Bring positivity to a dreary autumn day by forgetting the outside world and focussing on creating your own miniature plant world! My step-by-step terrarium planting guide will help you plant your own long-lasting indoor centrepiece to enhance your home this autumn and winter. Get ready to make the most of the longer evenings getting busy designing your own plant paradise!
A terrarium creates a perfect environment for small plants that thrive in low light levels and high humidity. Choose short-growing species that will not out-grow their enclosure as they mature. Options include miniature ferns, Begonias, and Fittonias. Also known as ‘nerve plants’, colourful Fittonias possess green leaves with stunning-coloured veins in various shades of pink, orange, red, green, and white. To see my planting list for terrariums and bottle gardens, please click here.
A word of warning!
When planting a terrarium, vivarium, or bottle garden avoid cacti and succulents – these plants grow in bright and sunny, dry, arid conditions – the total opposite to the environment a terrarium creates!
Choose a terrarium
Select a clear glass container with a large enough opening that allows you to reach into the centre for planting. A 30cm (11.8”) diameter terrarium is an effective size; it works well for plants and makes a versatile feature. Generally speaking, the larger your terrarium is, the easier it is to care for.
To ensure you choose a large enough enclosure, measure the height of your prospective terrarium, and ensure it can accommodate the height of your fully-grown plants, but don’t stop there – remember to allocate space for a compost layer measuring at least 6-7cm (2-3”) deep, plus a 2-3cm (1”) layer of grit for drainage. If you skimp on space for drainage and compost your plants won’t flourish.
- A large, clear glass vessel: an old fish tank, a glass jar, vase, or an old carboy.
- An empty plastic bottle (or alternatively a large, flexible sheet of plastic or card): to make a funnel.
- Grit: to form a drainage layer at the base of your terrarium.
- Activated charcoal: to keep the compost sweet (available online and from aquarium and shops).
- Peat-free compost.
- A piece of weed suppressant fabric, or an old t-shirt, or material remnant: to create a barrier that will allow water through but prevent the compost from blending into the drainage layer below.
- Terrarium plants: choose species that form naturally small plants, suited to growing in low light levels and high humidity. See my planting list for terrariums and bottle hardens by clicking here.
- A piece of rubber matting to place under your finished terrarium (I used an off-cut of pond liner from my new wildlife pond).
- Wash your clear glass vessel and allow to dry.
- Water your plants to ensure that they are hydrated before planting.
- Cut the bottom off a plastic bottle or twist a sheet of plastic or card to make a funnel and secure with tape.
- Hold the funnel inside the opening of your terrarium and add a fine layer of activated charcoal over the base.
- Next, add a 2-3cm (1”) layer of grit mixed with activated charcoal in the base of your terrarium.
- Sprinkle a thin layer of activated charcoal over the grit.
- Cut your weed suppressant fabric or barrier material to size to cover the entire drainage layer at the base.
- Now cover the charcoal and grit with a piece of weed suppressant fabric or material that covers the base from edge to edge, all the way around. This covering will create a barrier to keep the compost separate from the drainage layer below.
- Check your peat-free compost with your hands – it should be moist, but not wet or waterlogged.
- This might not be needed, but, if necessary, use a small watering can or mister to moisten the compost; remembering that it is much easier to add water than remove it – use a small amount of water and a fine nozzle.
- Add a few tablespoons of activated charcoal to the compost.
- Next, use the funnel as you add the compost to create a layer about 6-7cm (2-3”) deep.
- Now you’re ready to plant your terrarium! Arrange your plants inside your terrarium to decide on your design before planting.
- When planting, avoid placing your plants tight up against the glass and don’t cram plants too closely together.
- Place your planted terrarium directly onto the piece of rubber matting. The cushioned surface will help protect your terrarium from breaking should any debris get between the glass and the surface it’s stationed on.
This stunning terrarium was given to me by Growth Technology Products several years ago. It’s actually a lantern style terrarium, and comes complete with a battery-run LED light that’s concealed in the lid. I love the look of this terrarium and it’s the perfect size for a miniature fern or Fittonia; I’ve planted my Growth Technology Products’ terrarium with a pretty Selaginella apoda.
NB: On their website this terrarium is called a Wardell Terrarium – here’s a link to the product on Growth Technology Products’ website.
Position your planted terrarium in a bright to semi-shaded position, away from harsh or direct sunlight, cold draughts, and extremes of temperature. The middle of the room is usually a good location. Position your terrarium further away from the window in an exceptionally bright room and nearer the window in a shaded room.
- If you water your plants before planting and use moist compost, you won’t need to water your terrarium for a few days at least.
- Feel the compost around your plants’ roots and check the moisture levels before you water.
- Small hand-held misters are useful for increasing the humidity levels inside terrariums and bottle gardens.
Find my Calendar of Houseplant Fairs, more houseplant articles, more terrarium articles, and plant pages for terrarium plants, terrarium ferns, and houseplants!
To see my houseplant plant pages, please click here.
To see more houseplant articles, please click here.