Peat Free Compost Trial 2017, Growing Calendula

Contents

Why Peat Free Compost?

There are many wild, beautiful, and fascinating areas of our planet that are diminishing due to human destruction.  These precious natural areas require our protection urgently, before it’s too late and they are destroyed or lost altogether.  There are relatively small areas of rainforests, peat bogs and peatlands remaining on our planet, yet these areas are continuing to be destroyed by humans.  The brutality that humans have inflicted on this planet must stop.  We must all work together to protect, savour, celebrate, and cherish what remains of these special environments and eco systems, and work to conserve, regenerate, and rebuild these precious habitats.

Peat has been widely, and abundantly, used in the horticultural industry, usually entirely unnecessarily, over a great many years now.  Many gardeners have a familiarity with, and fondness for their peat based composts.  The compost blends and recipes, and ideas on use have often been passed down from grandparents and parents, to children and grandchildren, so consequently, peat based compost blends often bring with them a significant emotional attachment, evoking memories which can bestow an almost magical quality onto peat based compost, as happy memories and associations come flooding back during use.

It is a mistake to believe that a peat based compost is a better compost, as this is simply not true at all.  Different plants naturally require different composts, soils, and growing conditions, to flourish.  There are many plants, for example snowdrops, that do not grow at all well in a peat based compost, yet thrive when they’re grown in a peat free compost.

I am not trying to kid you, there are a few plants which do favour peat free composts, carnivorous plants, for example.  However, nearly all plants will flourish in both peat free or peat based composts, and in these cases most especially I would urge and encourage you to use peat free composts, to avoid contributing to the unnecessary destruction of our precious peat bogs and peatlands.

Compost labelling

If you wish to use only peat free composts, to assist you as much as I can, I must firstly clarify that if you’re looking to purchase a compost which does not contain any peat in its composition, then you need to look for a compost which is explicitly labelled as ‘Peat Free’.  The packaging, labelling, and descriptions displayed on compost bags can at times be confusing.  With a cursory glance, it could be easy to mistake a peat based compost for a peat free compost, and a compost may appear to be more environmentally friendly than it actually is.  To clarify, all of the composts that were featured in this particular Compost Trial are 100% peat free.

I want to help you to find the best peat free composts, so that you can garden easily, happily, and successfully, with no ill effects whatsoever from the compost you use.  With this aim in mind, I have conducted this Peat Free Compost Trial, to test out the peat free composts on the market, to see how they perform when trialled alongside each other, under the same conditions, so that you can find the best peat free composts to use at your own gardens and allotments.

Peat Free Composts

Each of the composts that I selected for this trial were purchased at the same time, so as to avoid trialling old composts, which might have been depleted of nutrients, and to ensure a fair trial of every compost.

I chose the following peat free composts and compost blends for my trial:

  • B&Q Verve Peat Free Multi-Purpose Compost
  • Carbon Gold All Purpose Compost
  • Dalefoot Composts Double Strength Wool Compost
  • Dalefoot Composts Wool Potting Compost
  • Dalefoot Wool Compost for Vegetables and Salads
  • Dalefoot Composts 50/50 Double Strength Wool Compost and Dalefoot Composts Wool Potting Compost
  • Dalefoot Composts 50/50 Double Strength Wool Compost and Dalefoot Composts Wool Compost for Vegetables and Salads
  • Fertile Fibre Biodynamic Demeter Multipurpose Compost
  • Fertile Fibre Multipurpose Compost
  • Fertile Fibre Vegro Multipurpose Compost
  • Miracle-Gro Peat Free All Purpose Enriched Compost
  • Sylva Grow Sustainable Growing Media
  • Westland Gro-Sure Peat Free All Purpose Compost
  • Wickes Peat Free Multi-Purpose Compost
  • Wyevale Peat Free Multi Purpose Compost

Peat Free Composts trialled for my 2017 Peat Free Compost Trial, Growing Calendula.

Seeds

Calendula offinalis ‘Snow Princess’ seeds from Thompson & Morgan.

For this particular Peat Free Compost Trial, I opted to sow seeds of Calendula officinalis ‘Snow Princess’, a hardy annual, which produces pretty flowers, whose soft yellow coloured petals gently fade to a creamy yellow as they age.  The oldest Calendula officinalis ‘Snow Princess’ flowers display petals which have blanched to an antique cream tone, meaning that plants display two, to three different tones of soft yellow coloured flowers at any one time.  This multi toned effect is rather pleasing, it really adds to the plant’s interest and charm.

A closer look at Calendula officinalis ‘Snow Princess’ seeds. Calendula seeds are fascinating!

Calendula officinalis ‘Snow Princess’ grown in Fertile Fibre Biodynamic Demeter Compost, as pictured on the 1st July 2017.

Some Calendula officinalis ‘Snow Princess’ plants produce flowers which feature yellow centres to their flowers, while other plants produce flowers which display brown centres, these flowers resemble mini sunflowers when used as cut flowers.  There are other subtle differences too: some plants produce flowers with smaller centres than others, while a number of plants produce flowers which are semi double, and feature a greater number of petals.

Calendula officinalis ‘Snow Princess’ in flower, as pictured on the 1st July 2017. These plants were grown in Fertile Fibre Vegro Multipurpose Compost, for my 2017 Compost Trial.

Calendula officinalis ‘Snow Princess’ in flower, as pictured on the 1st July 2017. This plant was grown in Dalefoot Composts 50/50 Double Strength Wool Compost and Dalefoot Composts Wool Compost for Vegetables and Salads, for my 2017 Compost Trial.

I purchased my Calendula officinalis ‘Snow Princess’ seeds from Thompson & Morgan.

2017 Peat Free Compost Trial

This Peat Free Compost Trial began on Saturday 15th April 2017, when thirteen Calendula officinalis ‘Snow Princess’ seeds were sown directly into containers filled with one of the aforementioned peat free composts, and compost blends featured in this Peat Free Compost Trial.

Each container of compost experienced the same conditions.  The Calendula plants were observed as they grew, and the results were monitored and recorded.

Irrigation

I had intended that the Calendula officinalis ‘Snow Princess’ plants that were grown for this 2017 Compost Trial would be almost entirely watered by the rain.  However, during periods of warm, dry weather, I found that the non Dalefoot Compost mixes were quite quick to dry out.  As a consequence, may of the Calendula plants that were grown for this Compost Trial required more frequent watering than I had expected, and so more frequent monitoring of the plants was required.  All of the Calendula officinalis ‘Snow Princess’ plants that were grown for this Compost Trial experienced the same conditions, at every stage of the trial.

Moisture retentive composts

Of the Dalefoot Composts blends that were trialled during this particular Compost Trial, I found that the Dalefoot Composts Double Strength Wool Compost, when used neat, was the most moisture retentive of all of the composts that were featured in this Compost Trial.  In my other Compost Trials I have noted that the composts produced by Dalefoot Composts, which are made from natural ingredients including bracken and sheep’s wool, offered greater moisture retention than the composts produced by the other brands trialled, but I have never previously noticed that one type of Dalefoot Compost was more water retentive than another, until now.

There was never a time during this Compost Trial, that I needed to water any of the Dalefoot Composts, especially the Dalefoot Composts Double Strength Wool Compost.  However, as this is a trial, I had to give all of the composts, and the plants growing in each compost, the exact same treatment.  So although the Dalefoot Composts Double Strength Wool Potting Compost remained moist and the plants were initially in very good shape, and did not require any additional irrigation whatsoever, as all of the Calendula officinalis ‘Snow Princess’ plants, which were grown in all of the non Dalefoot Composts, were suffering from the ill effects caused by drought and insufficient moisture, I had to make the decision to water all of the containers.  Each container of compost was given the same quantity of water, even though the containers of Dalefoot Compost didn’t require any water whatsoever.  Indeed, giving the Calendula officinalis ‘Snow Princess’ plants that were growing in the moisture retentive Dalefoot Composts, especially the plants that were growing in the Dalefoot Double Strength Compost, more water was highly detrimental to the health of these plants.  However, if I had not watered the non Dalefoot Composts, the Calendula officinalis ‘Snow Princess’ plants that were growing in the non Dalefoot composts would have died, and that would have been the end of this Compost Trial for those compost blends, which I didn’t think was fair.  I wanted to give the other compost brands the best chance of success, so all of the Calendula plants were watered.

A closer look at the waterlogged compost of Dalefoot Double Strength Wool Compost. Pictured during my Compost Trial on the 1st July 2017.

This same experience happened repeatedly throughout this particular Compost Trial.  The non Dalefoot composts needed irrigation, while the Dalefoot Composts did not require any additional water or attention.  Had I not watered the Calendula officinalis ‘Snow Princess’ plants that were growing in the Dalefoot Composts Double Strength Wool Compost, these plants would have flourished, but the other plants, which were growing in the non Dalefoot Composts would have died.

The photograph you see above was taken of Dalefoot Composts Double Strength Wool Compost during this trial.  As you can see, this compost is saturated with water, I have created a potted swamp!  These are not the conditions that I was hoping to create for this Compost Trial!  I am so sorry to Dalefoot Composts, as the Calendula plants that were grown in their composts would have performed so much better without the unnecessary irrigation and the corresponding adverse conditions that the plants grown in their composts endured

In addition to the unnecessary irrigation, Dalefoot Composts Double Strength Wool Compost isn’t designed to be used neat from the bag, which is exactly how I have used it in this Compost Trial, and in many of my other Compost Trials.  Dalefoot Composts Double Strength Wool Compost is a powerful, nutrient rich, concentrated compost, which was created and designed to be added to spent compost, to enrich the compost and create a viable growing medium.  When used in the way in which it was designed, and is recommended to be used, Dalefoot Composts Double Strength Compost performs so much better, and it goes a lot further too!

Tips for successful container gardening

If you live in an area with frequent rainfall, or if you will be using Dalefoot Compost, or another moisture retentive compost over the winter months, which tend to be wetter, you can still use Dalefoot Double Strength Wool Compost effectively and successfully.  Firstly, I would advise you to use the Double Strength Wool Compost in the manner in which it was intended to be used –  mixed with a spent compost or your garden soil.  You can also add sand or grit to your Dalefoot Compost Double Strength Compost, to create a more open, free draining compost blend if you wish.

Of course, it goes without saying that you should only use a container that has drainage holes at the base, to allow water to easily escape out of the container (the containers used for this trial, are all the same and all feature drainage holes – I would never use a container without drainage holes at the base, unless I was creating a pond!)

I often find that the compost within a terracotta pot tends to dry out more rapidly that the same compost mix would when used inside a plastic pot, as terracotta can be rather absorbent.  I much prefer terracotta pots to plastic too!   You can of course position your containers in a sheltered location, where they will receive less rainwater, or you could cover your plants to protect them from the weather as necessary.

When you’re gardening, it’s wise to regularly check on your plants to avoid suddenly discovering that your plants have been enduring some unnecessary, and easily averted trauma.  Before watering your plants, feel the compost to see if it is dry and find out if it really needs watering.  Compost is lighter when it’s dry.  You might discover that a potted plant has dried out, as you come to move the pot, when you surprise yourself at how the container feels extraordinarily light, and weighs far less than you expect.  For established plants, you can even tip your plant out of its pot and examine your plant’s roots and growing media, if you want to.  It’s important to remember that the effects plants display when they have been over watered can look almost exactly the same as the effects of under watering – plants are limp and flopping and their leaves can sometimes  turn as more yellowish shade of unpleasant, unforgiving green.  Having your plants constantly siting in a wet, saturated compost is just as likely to kill your plants as if you do not water your plants at all and they experience a severe drought.

Avoid over potting your plants

I would always advise against over potting your plants.  A more successful way to grow Calendula officinalis ‘Snow Princess’ plants, or indeed any plants, would be to sow your seeds into small pots filled with compost, and then pot your plants up at regular intervals as they grow, increasing the size of your pot by a couple of sizes at a time.  For this Compost Trial, I have tried to show how you can grow an annual flowering plant over the summer by simply sowing some seeds in a pot of compost, leaving the plants to grow and flower, without being potted on. This is however not the best way to garden.  For optimum results do pot your plants up regularly.

I am amazed that the Calendula officinalis ‘Snow Princess’ plants that were grown in the various Dalefoot Composts for this particular Compost Trial, especially the Dalefoot Double Strength Compost, performed as well as they did after enduring such unfavourable conditions throughout this particular Compost Trial.

If you’re looking for tips on how to successfully plant up containers, please click here.

Calendula flowering times

Generally speaking, the Calendula officinalis ‘Snow Princess’ plants that were grown for this Compost Trial reached flowering size by the middle of June 2017 (these plants were raised from seeds which were sown outside, without any protection, on the 15th April 2017).  Of course there were exceptions, sadly the Calendula plants that were grown in Wickes Peat Free Multi Purpose Compost did not manage to produce any flowers.  Of the flowering Calendula plants, the plants that were grown in the Dalefoot Composts Double Strength Wool Compost, used in its neat form, were the last to come into flower.

The first Calendula officinalis ‘Snow Princess’ plant to come into flower was grown in Fertile Fibre Biodynamic Demeter Multipurpose Compost.  This first flower opened on the 17th June 2017.  The next Calendula plant to flower was grown in Fertile Fibre Vegro Multipurpose Compost, this plant started blooming on the 19th June 2017.

On the 21st June 2017, the Calendula plants grown in the Dalefoot Composts Wool Potting Compost came into flower.  You can see the flower production of all of the Calendula officinalis ‘Snow Princess’ plants grown for this Compost Trial in this table below.

This table shows the total number of flowers harvested from the Calendula officinalis ‘Snow Princess’ plants, by date and compost type.

The last Calendula officinalis ‘Snow Princess’ plants to come into bloom were grown in Dalefoot Composts Double Strength Wool Compost, used in its neat form.  These Calendula plants were set back, having been adversely affected by the excessive water levels in this compost.  Consequently, the first flowers harvested from these plants were collected on the 15th August 2017.

The last harvest of all of the Calendula officinalis ‘Snow Princess’ flowers grown for this Compost Trial was collected on the 19th November 2017.  All of the Calendula plants grown for this trial were looking very scrappy and tatty in their appearance long before this time, although the plants still continued to flower.

After the last flower harvest on the 19th November 2017, the containers of Calendula officinalis ‘Snow Princess’ plants that were grown for this Compost Trial were left outside without any protection, or any attention paid to them.  No deadheading, watering, or attention was paid to these plants after the 19th November 2017.

On the 14th January 2018, it was noted that the Calendula officinalis ‘Snow Princess’ plants that were growing in Dalefoot Composts Wool Potting Compost, Dalefoot Wool Compost for Vegetables and Salads, Miracle Gro Peat Free All Purpose Enriched Compost, and Wyevale Peat Free Multi Purpose Compost had continued to flower, and were in bloom at this time.

Calendula officinalis ‘Snow Princess’ plants

Here is a clearer look at the Calendula officinalis ‘Snow Princess’ plants that were grown for this Compost Trial.  The plants were all photographed on the same date so their growth and development could be assessed and compared more easily.

B&Q Verve Peat Free Multi-Purpose Compost

Calendula officinalis ‘Snow Princess’ in flower, as pictured on the 1st July 2017. These plants were grown in B&Q Verve Peat Free Multi-Purpose Compost, for my 2017 Compost Trial.

Calendula officinalis ‘Snow Princess’ in flower, as pictured on the 22nd August 2017. These plants were grown in B&Q Verve Peat Free Multi-Purpose Compost, for my 2017 Compost Trial.

Calendula officinalis ‘Snow Princess’ plants, as pictured on the 30th September 2017. These plants were grown in B&Q Verve Peat Free Multi-Purpose Compost, for my 2017 Compost Trial.

The Calendula officinalis ‘Snow Princess’ plants that were grown in B&Q Verve Peat Free Multi-Purpose Compost formed plants which were small in size, short in height and less bushy and branching in their nature than I had hoped for.

Carbon Gold All Purpose Compost

Calendula officinalis ‘Snow Princess’ in flower, as pictured on the 1st July 2017. These plants were grown in Carbon Gold All Purpose Compost, for my 2017 Compost Trial.

Calendula officinalis ‘Snow Princess’ in flower, as pictured on the 22nd August 2017. These plants were grown in Carbon Gold All Purpose Compost, for my 2017 Compost Trial.

Calendula officinalis ‘Snow Princess’ plants, as pictured on the 30th September 2017. These plants were grown in Carbon Gold All Purpose Compost, for my 2017 Compost Trial.

 

Dalefoot Composts Double Strength Wool Compost

Calendula officinalis ‘Snow Princess’, as pictured on the 1st July 2017. These plants were grown in Dalefoot Composts Double Strength Wool Compost used neat, for my 2017 Compost Trial.

Calendula officinalis ‘Snow Princess’ in flower, as pictured on the 22nd August 2017. These plants were grown in Dalefoot Composts Double Strength Wool Compost, for my 2017 Compost Trial.

Calendula officinalis ‘Snow Princess’ plants, as pictured on the 30th September 2017. These plants were grown in Dalefoot Composts Double Strength Wool Compost, for my 2017 Compost Trial.

Dalefoot Composts Wool Potting Compost

Calendula officinalis ‘Snow Princess’ in flower, as pictured on the 1st July 2017. These plants were grown in Dalefoot Composts Wool Potting Compost, for my 2017 Compost Trial.

Calendula officinalis ‘Snow Princess’ in flower, as pictured on the 22nd August 2017. These plants were grown in Dalefoot Composts Wool Potting Compost, for my 2017 Compost Trial.

Calendula officinalis ‘Snow Princess’ plants, as pictured on the 30th September 2017. These plants were grown in Dalefoot Composts Wool Potting Compost, for my 2017 Compost Trial.

Dalefoot Wool Compost for Vegetables and Salads

Calendula officinalis ‘Snow Princess’ in flower, as pictured on the 1st July 2017. These plants were grown in Dalefoot Wool Compost for Vegetables and Salads, for my 2017 Compost Trial.

Calendula officinalis ‘Snow Princess’ in flower, as pictured on the 22nd August 2017. These plants were grown in Dalefoot Wool Compost for Vegetables and Salads, for my 2017 Compost Trial.

Calendula officinalis ‘Snow Princess’ plants, as pictured on the 30th September 2017. These plants were grown in Dalefoot Wool Compost for Vegetables and Salads, for my 2017 Compost Trial.

Dalefoot Composts 50/50 Double Strength Wool Compost and Dalefoot Composts Wool Potting Compost

Calendula officinalis ‘Snow Princess’ in flower, as pictured on the 1st July 2017. These plants were grown in a blend of Dalefoot Composts 50/50 Double Strength Wool Compost and Dalefoot Composts Wool Potting Compost, for my 2017 Compost Trial.

Calendula officinalis ‘Snow Princess’ in flower, as pictured on the 22nd August 2017. These plants were grown in blend of Dalefoot Composts 50/50 Double Strength Wool Compost and Dalefoot Composts Wool Potting Compost, for my 2017 Compost Trial.

Calendula officinalis ‘Snow Princess’ plants, as pictured on the 30th September 2017. These plants were grown in a blend of Dalefoot Composts 50/50 Double Strength Wool Compost and Dalefoot Composts Wool Potting Compost, for my 2017 Compost Trial.

Dalefoot Composts 50/50 Double Strength Wool Compost and Dalefoot Composts Wool Compost for Vegetables and Salads

Calendula officinalis ‘Snow Princess’ as pictured on the 1st July 2017. These plants were grown in a blend of Dalefoot Composts 50/50 Double Strength Wool Compost and Dalefoot Composts Wool Compost for Vegetables and Salads, for my 2017 Compost Trial.

Calendula officinalis ‘Snow Princess’ in flower, as pictured on the 22nd August 2017. These plants were grown in blend of Dalefoot Composts 50/50 Double Strength Wool Compost and Dalefoot Composts Wool Compost for Vegetables and Salads, for my 2017 Compost Trial.

Calendula officinalis ‘Snow Princess’ plants, as pictured on the 30th September 2017. These plants were grown in a blend of Dalefoot Composts 50/50 Double Strength Wool Compost and Dalefoot Composts Wool Compost for Vegetables and Salads, for my 2017 Compost Trial.

Fertile Fibre Biodynamic Demeter Multipurpose Compost

Calendula officinalis ‘Snow Princess’ in flower, as pictured on the 1st July 2017. These plants were grown in Fertile Fibre Biodynamic Demeter Multipurpose Compost, for my 2017 Compost Trial.

Calendula officinalis ‘Snow Princess’ in flower, as pictured on the 22nd August 2017. These plants were grown in Fertile Fibre Biodynamic Demeter Multipurpose Compost, for my 2017 Compost Trial.

Calendula officinalis ‘Snow Princess’ plants, as pictured on the 30th September 2017. These plants were grown in Fertile Fibre Biodynamic Demeter Multipurpose Compost, for my 2017 Compost Trial.

Fertile Fibre Multipurpose Compost

Calendula officinalis ‘Snow Princess’ in flower, as pictured on the 1st July 2017. These plants were grown in Fertile Fibre Multipurpose Compost, for my 2017 Compost Trial.

Calendula officinalis ‘Snow Princess’ in flower, as pictured on the 22nd August 2017. These plants were grown in Fertile Fibre Multipurpose Compost, for my 2017 Compost Trial.

Calendula officinalis ‘Snow Princess’ plants, as pictured on the 30th September 2017. These plants were grown in Fertile Fibre Multipurpose Compost, for my 2017 Compost Trial.

Fertile Fibre Vegro Multipurpose Compost

Calendula officinalis ‘Snow Princess’ in flower, as pictured on the 1st July 2017. These plants were grown in Fertile Fibre Vegro Multipurpose Compost, for my 2017 Compost Trial

Calendula officinalis ‘Snow Princess’ in flower, as pictured on the 22nd August 2017. These plants were grown in Fertile Fibre Vegro Multipurpose compost, for my 2017 Compost Trial.

Calendula officinalis ‘Snow Princess’ plants, as pictured on the 30th September 2017. These plants were grown in Fertile Fibre Vegro Multipurpose Compost, for my 2017 Compost Trial.

Miracle-Gro Peat Free All Purpose Enriched Compost

Calendula officinalis ‘Snow Princess’ in flower, as pictured on the 1st July 2017. These plants were grown in Miracle-Gro Peat Free All Purpose Enriched Compost, for my 2017 Compost Trial.

Calendula officinalis ‘Snow Princess’ in flower, as pictured on the 22nd August 2017. These plants were grown in Miracle Gro Peat Free All Purpose Enriched Compost, for my 2017 Compost Trial.

Calendula officinalis ‘Snow Princess’ plants, as pictured on the 30th September 2017. These plants were grown in Miracle-Gro Peat Free All Purpose Enriched Compost, for my 2017 Compost Trial.

Sylva Grow Sustainable Growing Media

Calendula officinalis ‘Snow Princess’ in flower, as pictured on the 1st July 2017. These plants were grown in Sylva Grow Sustainable Growing Media, for my 2017 Compost Trial.

Calendula officinalis ‘Snow Princess’ in flower, as pictured on the 22nd August 2017. These plants were grown in Sylva Grow Sustainable Growing Media, for my 2017 Compost Trial.

Calendula officinalis ‘Snow Princess’ plants, as pictured on the 30th September 2017. These plants were grown in Sylva Grow Sustainable Growing Media, for my 2017 Compost Trial.

Westland Gro-Sure Peat Free All Purpose Compost

Calendula officinalis ‘Snow Princess’ in flower, as pictured on the 1st July 2017. These plants were grown in Westland Gro-Sure Peat Free All Purpose Compost, for my 2017 Compost Trial.

Calendula officinalis ‘Snow Princess’ in flower, as pictured on the 22nd August 2017. These plants were grown in Westland Gro-Sure Peat Free All Purpose Compost, for my 2017 Compost Trial.

Calendula officinalis ‘Snow Princess’ plants, as pictured on the 30th September 2017. These plants were grown in Westland Gro-Sure Peat Free All Purpose Compost, for my 2017 Compost Trial.

Wickes Peat Free Multi-Purpose Compost

Calendula officinalis ‘Snow Princess’, as pictured on the 1st July 2017. These plants were grown in Wickes Peat Free Multi-Purpose Compost, for my 2017 Compost Trial.

Calendula officinalis ‘Snow Princess’, as pictured on the 22nd August 2017. These plants were grown in Wickes Peat Free Multi-Purpose Compost, for my 2017 Compost Trial.

Calendula officinalis ‘Snow Princess’ plants, as pictured on the 30th September 2017. These plants were grown in Wickes Peat Free Multi-Purpose Compost, for my 2017 Compost Trial.

The Calendula officinalis ‘Snow Princess’ plants that were grown in Wickes Peat Free Multi-Purpose Compost, for this Compost Trial achieved 100% germination.  Following on from germination the plants did not grow or develop as I would have hoped.  These small weak Calendula plants appeared to have been suspended in time, as they remained the same size for the majority of this trial, never managing to produce a single flower.

Wyevale Peat Free Multi Purpose Compost

Calendula officinalis ‘Snow Princess’ in flower, as pictured on the 1st July 2017. These plants were grown in Wyevale Peat Free Multi Purpose Compost, for my 2017 Compost Trial.

Calendula officinalis ‘Snow Princess’ in flower, as pictured on the 22nd August 2017. These plants were grown in Wyevale Peat Free Multi Purpose Compost, for my 2017 Compost Trial.

Calendula officinalis ‘Snow Princess’ plants, as pictured on the 30th September 2017. These plants were grown in Wyevale Peat Free Multi Purpose Compost, for my 2017 Compost Trial.

The Calendula officinalis ‘Snow Princess’ plants that were grown in Wyevale Peat Free Multi Purpose Compost, for this Compost Trial, very noticeably germinated on one side of the compost in the pot they were growing in.  I assume that one side of this compost received more shade than the other while the seeds were germinating, if this was the case, I assume that the shaded side allowed one side of the compost to remain just moist enough to allow for the germination of the Calendula seeds, while the other side was just too dry for successful germination.  Another explanation for this difference in plant growth is that a slug, snail, or other creature ate the germinating seedlings on one side of the pot and left the other side alone.  However, I believe that my first assumption is more likely.

Calendula officinalis ‘Snow Princess’ flowers

A vase of Calendula officinalis ‘Snow Princess’ flowers picked from Calendula plants that were grown for my 2017 Compost Trial. Pictured on the 24th June 2017.

A vase of Calendula officinalis ‘Snow Princess’ flowers picked from Calendula plants that were grown for my 2017 Compost Trial. Pictured on the 1st July 2017.

A vase of Calendula officinalis ‘Snow Princess’ flowers picked from Calendula plants that were grown for my 2017 Compost Trial. Pictured on the 8th July 2017.

A vase of Calendula officinalis ‘Snow Princess’ flowers picked from Calendula plants that were grown for my 2017 Compost Trial. Pictured on the 15th July 2017.

A vase of Calendula officinalis ‘Snow Princess’ flowers picked from Calendula plants that were grown for my 2017 Compost Trial. Pictured on the 30th July 2017.

A vase of Calendula officinalis ‘Snow Princess’ flowers picked from Calendula plants that were grown for my 2017 Compost Trial. Pictured on the 26th August 2017.

A vase of Calendula officinalis ‘Snow Princess’ flowers picked from Calendula plants grown for my 2017 Compost Trial. Pictured on the 10th September 2017.

A vase of Calendula officinalis ‘Snow Princess’ flowers picked from Calendula plants grown for my 2017 Compost Trial. Pictured on the 30th September 2017.

Pests and Diseases

The main problems that the Calendula officinalis ‘Snow Princess’ plants encountered during this particular Compost Trial were to do with irrigation – receiving too much or insufficient water.  Although for some plants, most noticeably those grown in the Wickes Peat Free Multi-Purpose Compost, their biggest problem was the compost they were grown in, which did not provide the plants with sufficient nutrients to allow for successful growth.  Apart from these troubles, the Calendula officinalis ‘Snow Princess’ plants grown for this Compost Trial were not troubled by pests.

Aphids

There is a tiny aphid on this Calendula officinalis ‘Snow Princess’ flower, as pictured on the 30th August 2017. This plant was grown in Dalefoot Composts 50/50 Double Strength Wool Compost and Dalefoot Composts Wool Potting Compost, for my 2017 Compost Trial.

You might just be able to make out the aphid in the centre of the Calendula officinalis ‘Snow Princess’ bloom pictured above.  Aphids were seen occasionally, in very small numbers, on the Calendula officinalis ‘Snow Princess’ plants that were grown for this Compost Trial.   Aphids were never a problem for any of the Calendula officinalis ‘Snow Princess’ plants during any any stage of this 2017 Compost Trial.

Slugs and snails

I won’t use any slug pellets under any circumstances, not even organic slug pellets.  I didn’t use any slug or snail deterrents, or any methods to prevent slugs and snails from accessing or eating the Calendula officinalis ‘Snow Princess’ plants that were grown for this Compost Trial.  If I saw a snail or a slug, I left the mollusk alone.  I never attempted to remove any slugs or snails from the area around the plants, or from the plants themselves.

This Calendula officinalis ‘Snow Princess’ plant has a young garden snail, also known by its scientific name of Cornu aspersum, hiding within its leaf. This plant was grown for my 2017 Compost Trial, and was pictured on the 26th July 2017.

Slugs and snails were seen frequently throughout the period of time that this Compost Trial ran for.  If I had spent any time looking I am sure I would have found slugs and snails around the plants grown for this trial every day.  Despite this none of the plants that were grown for this trial were adversely affected by either slugs or snails.  None of the plants were lost or disfigured by the slugs or snails.  Only very minor slug and snail damage was seen on the Calendula officinalis ‘Snow Princess’ plants that were grown for this trial.

This Calendula officinalis ‘Snow Princess’ plant has a heart shaped hole its leaf. This plant was grown for my 2017 Compost Trial, pictured on the 11th July 2017.

If you’re interested in protecting your plants from slugs and snails, you might be interested in reading about my Slug and Snail Trial.

Compost costs

The price of the composts I have trialled for this 2017 Peat Free Compost Trial vary greatly.

When comparing the trialled composts and their cost when purchasing one bag, the most expensive composts that featured in this trial were produced by Dalefoot Composts, their products cost 53 pence/litre.  The cheapest compost per litre for one bag was the B&Q Verve Peat Free Multi-Purpose Compost, which cost 8 pence/litre.

However, these prices apply when a customer purchases a single bag of compost at a time; it’s worth remembering that the price for some of the more expensive (usually mail-order) composts drops when you buy in bulk.  If you buy 5 or 10 bags of Dalefoot Compost, for example, the price per litre drops by 25%, from 53p/litre to 40p/litre.  When ordering compost you can make substantial savings by joining together with other gardeners, fellow allotment holders, friends, family, or neighbours, and making a bulk order of compost which is delivered to one address.

As I am writing about compost costs, I must say that Dalefoot Double Strength Wool Compost is not designed, or recommended, to be used in its neat form as I have used the compost in this trial.  This is a concentrated compost, made of a powerful blend of ingredients, which is designed to be mixed with spent compost to create a viable growing medium.  When used in the manner for which it was designed, a bag of Dalefoot Double Strength Compost becomes very good value indeed, and as I have found in previous Compost Trials, the plants that were grown in a mixture of spent compost and Dalefoot Double Strength Wool Compost perform much better than the plants which are grown in this compost when its used in its neat form.

A bulk discount does not apply to all of the  trialled composts though; Carbon Gold Gro-Char costs the same regardless of the quantity purchased, meaning that this compost is by far the most expensive compost in the trial when more than one bag of compost is purchased.

Although the mail-order composts featured in this trial have generally proved themselves to be of better quality (in terms of harvest and plant health – see the results below), cost is one factor where the mail order composts can’t compete with the more widely available brands such as Miracle-Gro and Westland.  By virtue of their many local stockists, these garden centre branded composts are available for collection, and so consequently do not incur a delivery fee, making them significantly cheaper – in some cases a quarter of the cost of the more expensive mail-order brands.  However if you require a taxi, or are unable to carry a hefty bag of compost yourself, you will appreciate being able to purchase a top quality compost and have it delivered directly to your garden or allotment.

One way that you can get the best of both worlds – to use a great compost without a great cost – is to mix spent compost with a premium mail-order brand.  For example, in previous Peat Free Compost trials, I have shown that mixing a spent compost, which was unable to sustain plant growth much beyond germination when used alone, with Dalefoot Double Strength Wool Compost, a concentrated compost made of powerful ingredients that is designed to be used in this manner.  By combining a top quality, concentrated compost formula with your own spent compost you will receive excellent results at a greatly reduced cost.

This chart shows the price per litre for the different types of compost and for different amounts (1, 5, and 10 bags). You can see that for the compost bought at local suppliers (garden centres etc) the lack of delivery fees keeps the price low, and many of the garden centres have offers that make it cheaper to buy more (e.g. buy-one-get-one-free, three for £10 etc).
The composts that are delivered are more expensive per litre, but the way delivery is charged can significantly affect the price. For example, Dalefoot’s flat delivery rate (£5 for up to 11 bags) means that a bulk load really brings the price per litre down. This contrasts with Carbon Gold, who charge a per-bag delivery fee regardless of quantity – making their compost (which already costs £19/bag) much more expensive to buy.

Calendula Compost Trial Results

This table shows the total number of flowers harvested from the Calendula officinalis ‘Snow Princess’ plants, by date and compost type.

This table shows the total number of flowers harvested from the Calendula officinalis ‘Snow Princess’ plants, by date and compost type.

2017 Peat Free Compost Trial – Growing Calendula Conclusions

Final Compost Trial Ranking

I have ranked the trialled composts by the total number of flowers that the Calendula officinalis ‘Snow Princess’ plants grown in each of the trialled composts produced during this Compost Trial.

Compost Trial Conclusions

Rank Compost Type Conclusions

1

In first place, the clear winner and the best performing compost in this Compost Trial was a blend of Dalefoot Composts 50/50 Double Strength Wool Compost and Dalefoot Composts Wool Compost for Vegetables and Salads.  This compost blend performed exceptionally well, and consistently across this entire trial.  The Calendula plants grown in this compost produced the best harvest by some margin (28% more than the next-best compost, which was also a Dalefoot Compost).

2

In second place, Dalefoot Wool Compost for Vegetables and Salads, produced 10% more flowers than the 3rd placed compost, producing tall, yet upright, strong Calendula plants, that were productive and flowered prolifically.  The Calendula officinalis ‘Snow Princess’ plants that were grown in Dalefoot Wool Compost for Vegetables and Salads flowered consistently throughout this Compost Trial.  The Calendula plants that were grown in this compost continued to flower long after this trial had finished.

3

In third place, Dalefoot Composts Wool Potting Compost produced plants that generated 10% more flowers than the 4th placed compost in this trial.  The Calendula officinalis ‘Snow Princess’ plants that were grown in Dalefoot Composts Wool Potting Compost were tall, upright, strong and healthy.  The Calendula plants that were grown in this compost flowered prolifically with great longevity, the plants continued to flower, with no dead heading or maintenance long after this Compost Trial had finished.

4

In fourth place, a blend of Dalefoot Composts 50/50 Double Strength Wool Compost and Dalefoot Composts Wool Potting Compost produced plants that generated 18% more flowers than the 5th placed compost.  This compost blend produced large Calendula plants.  This compost blend was full of nutrients, producing top sized plants that provided a great harvest of flowers through the summer months and into autumn.

5

In fifth place, the first non Dalefoot compost was Sylva Grow Sustainable Growing Medium, which performed well during this Compost Trial.  The Calendula officinalis ‘Snow Princess’ plants that were grown in Sylva Grow Sustainable Growing Medium produced just under half as many flowers as the winning compost during this particular Compost Trial.  Sylva Grow Sustainable Growing Medium produced Calendula plants that were 7% more productive than the 6th placed compost in this Compost Trial.

6

In sixth place, Fertile Fibre Vegro Multipurpose Compost produced Calendula plants that flowered early, and put in their best performance early on in the Trial.  As time passed, the Calendula plants that were grown in this compost flowered less consistently.  The Calendula officinalis ‘Snow Princess’ plants that were grown in Fertile Fibre Vegro Multipurpose Compost produced 7% fewer flowers than the Calendula plants that were grown in the 5th placed Sylva Grow Sustainable Growing Medium.  The Calendula plants that were grown in the composts that were placed in 5th, 6th, and 7th position were very close indeed in their productivity, all of these composts produced plants which generated just under half as many flowers as the winning Dalefoot Compost.

7

In seventh place, Fertile Fibre Biodynamic Demeter Multipurpose Compost produced very attractive looking Calendula officinalis ‘Snow Princess’ plants, which performed and flowered at their best very early on in the trial.  The Calendula plants grown in this compost lost their ‘oomph’ by mid July, after they had been growing for just 3 months and flowering for 1 month in this compost.  This compost produced just under half as many flowers as the winning Dalefoot Compost during this Compost Trial.

8

In eighth position, Carbon Gold All Purpose Compost produced attractive Calendula plants that flowered early and reached their peak of productivity very early on in this Trial.  The Calendula officinalis ‘Snow Princess’ plants that were grown in Carbon Gold All Purpose Compost produced 5% more flowers than the 9th placed compost in this Compost Trial.  The Calendula officinalis ‘Snow Princess’ plants grown in Carbon Gold All Purpose Compost produced 26% fewer flowers than those grown in Fertile Fibre Biodynamic Demeter Multipurpose Compost during this Compost Trial.

9

In ninth place, Dalefoot Double Strength Wool Compost was too powerful a blend of compost for the Calendula officinalis ‘Snow Princess’ plants that were grown for this Compost Trial.  The Calendula plants that were grown in this compost endured excessive water logging, and really terrible growing conditions.  Despite these significant set backs, the plants grown in this compost produced 23% more flowers than the plants grown in Fertile Fibre Multipurpose Compost.  I must say that I was surprised that the plants that were grown in this compost managed to survive the trial, let alone flower.

10

 In tenth place, Fertile Fibre Multipurpose Compost produced Calendula officinalis ‘Snow Princess’ plants that had a rather slimline, thin appearance.  These Calendula plants were less stocky and bushy than I would have wished for.  The Calendula officinalis ‘Snow Princess’ plants that were grown for this Compost Trial were not as strong, or as productive as I had hoped, yet the plants grown in this Compost produced 28% more flowers than the Calendula plants that were grown in the 9th placed Miracle-Gro Peat Free All Purpose Enriched Compost.  The plants grown in this compost did not flower consistently, they ran out of steam early in the trial and were the first of these trial grown plants to stop flowering.

11

In eleventh place, Miracle-Gro Peat Free All Purpose Enriched Compost, produced Calendula officinalis ‘Snow Princess’ plants that were altogether ‘less’ than I would have liked.  Having said this, a big plus point for the Calendula plants that were grown in this compost was their longevity, these plants were still producing flowers in January 2018, long after most of the other plants had ceased flowering and after this Compost Trial’s assessments had finished.

 12

In twelfth position, Wyevale Garden Centres Peat Free Multipurpose Compost produced Calendula officinalis ‘Snow Princess’ plants which also managed great longevity and were flowering in January 2018, two months after they were last deadheaded!  However, the Calendula officinalis ‘Snow Princess’ plants that were grown in this compost were often too dry, as this compost was not as water retentive as I had hoped, and these plants were not as productive as I had wished during the main part of this Compost Trial.

13

In thirteenth place, Westland Gro-Sure Peat Free All Purpose Compost produced Calendula officinalis ‘Snow Princess’ plants that were rather dwarf, much slimmer, more compact, and less floriferous than I had hoped for.  As this Compost Trial progressed, the Calendula officinalis ‘Snow Princess’ plants that were grown in Westland Gro-Sure Peat Free All Purpose Compost seemed to degrade, they become even more slender, with leaves that were smaller and thinner in their appearance.

14

In fourteenth position, B&Q Verve Peat Free Multipurpose Compost produced very small, stunted, dwarf Calendula officinalis ‘Snow Princess’ plants, that produced exceptionally small flowers.  The Calendula plants that were grown in B&Q Verve Peat Free Multipurpose Compost looked insignificant and fragile.  The plants grown in this compost were not strong or healthy, and they did not flower very often.

15

Finally, in fifteenth place, Wickes Peat Free Multi-Purpose Compost.   Sadly the Calendula officinalis ‘Snow Princess’ plants that were grown in Wickes Peat Free Multi Purpose Compost for this Compost Trial did not manage to grow strong enough to produce any flowers.  The Calendula plants that were grown in this compost were so very small in size that the container looked to be empty when viewed from most angles at every stage of this trial.  The plants grown in Wickes Peat Free Multi-Purpose Compost were stunted, and weak due to the lack of available nutrients provided by this compost.

Further Trials

You may be interested in some of the other trials I have conducted.

Compost Trial Reports

To see all of my Compost Trials, please click here.

To read advice on planting up containers, please click here.

Slug and Snail Trials

To read about effective methods of protecting your plants from slugs and snails, please click here.

Sweet Pea Trial Reports

To read the results of my 2017 Sweet Pea Trial, please click here.

To read the results of my 2016 Sweet Pea Trial, please click here.

To read the results of my 2015 Sweet Pea Trial, please click here.

Scented Daffodil Trial Reports

To read the results of my 2018 Scented Daffodil Container Trial, please click here.

To read the results of my 2017 Scented Daffodil Trial, please click here.

Terrarium, Vivarium, and Orchidarium Trials

To see how my Orchidarium was created, please click here.

To read the first part of my White Orchid BiOrbAir Terrarium Trial, please click here.

To read the first part of my Madagascar BiOrbAir Terrarium Trial, please click here.

To read the first part of my Miniature Orchid BiOrbAir Terrarium Trial, please click here.

To read about the general care I give to my orchids and terrarium plants, and the general maintenance I give to my BiOrbAir terrariums, please click here.

To read how I track the temperature, humidity, and light conditions inside my terrariums, my home, and garden, please click here.

Other articles that may interest you…………………..

To read tips and advice for growing Sweet Peas, please click here.

To read about growing mushrooms indoors, please click here.

For gardening advice, tips, and lovely ideas of what you could do in your garden, or at your allotment, in February, please click here.

For gardening advice, tips, and lovely ideas of what you could do in your garden, or at your allotment, from mid-February to mid-March, please click here.

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