A number of forms of air pruning pots are available, I am a fan of these types of containers, as they prevent plants’ roots from becoming pot-bound. I have found that plants grown in air pruning pots establish more readily when they’re planted in the garden, when compared to plants grown in regular containers. They’re very effective.
Last year, as part of my Tomato Trial, I used Haxnicks Vigoroot Planters for the first time.