What are Rootrainers?

Rootrainers are planting cells that have been used by professional growers for decades. Their three main advantages are:

  1. Plant roots are Air Pruned resulting in stronger healthier plants.
  2. Cells open for much less root disturbance
  3. They save space and compost

Lets look a bit deeper into each of those:

What is Air Pruning?

The grooves you see in Rootrainers aren't for show. The roots are guided down these until they come out of the bottom. Upon hitting the air, the root tip dies off. This causes the plant to send out more roots from the centre which again use the grooves as a guide. The end result of this is a plant that has lots of straight, strong roots with a fundamentally different - and better - structure than those grown in a pot.

Rootrainer plant cells diagram of how air prunign gives better roots

The plants will be stronger, healthier and cope better with sudden changes in temperature. They will also be more disease resistant as a result meaning you will have to use less fertilisers and pesticides to look after them.

Why is Root Disturbance a Problem?

Diagram showing straight roots grown in root trainer plant cells and tangled roots grown in a standard plant pot

For plants in a standard pot, as soon as the roots hit the side of the pot they follow it round and you end up with a tangled rootball. In order to plant them out this rootball needs to be teased apart.  Even if it is a plant that is OK with root disturbance, this process sends the plant into mild shock and delays it establishing in its new location.  If it is deep rooted plant such as a climbing bean or a sweet pea that really suffers when the roots are disturbed then this could mean a total failure of the plant.  

Rootrainer Cells solve this by opening up like a book. The seedlings can then be lifted out and transplanted without root disturbance. They can establish without delay to make the most of the growing season. so if you have heard of gardeners using Root trainers for sweet peas then this is the reason.

Rootrainers for Space Saving

This is one for you if you are short of space - 32 plants in the space that a laptop would take up?  Yes please! It will fit nicely on a window sill to start a very early crop like Broad Beans off and then use them once (or even twice) more in the same season for the rest of your veg.

Which Size Rootrainer Should I use?

When it comes to Rootrainers bigger is not better!

You might think that by putting your beans in the much deeper Maxi Rootrainers you will get larger stronger roots.  In actual fact you will just have to wait longer for the air pruning process to start which is unnecessary. Growers often claim the quicker a plant is in its final growing habitat, the better. Also, if you plant too deep the roots may be below the best top soil and be inhibited by poor soil.  So try to get the right size for your project.

Deep Rootrainers

32 Cells  Depth: 12cm Volume 175cc

deep rootrainers root trainer plant cells for planting seeds

Those vegetables with fast growing root structures, which is most commonly grown vegetables, prefer deep pots.  So your climbing beans, sweetcorn and of course sweet peas.  Plants that have to over-winter, like perennials may also benefit from Deep Rootrainers.

Cuttings of Fruit Bushes fare well in Deep Rootrainers

Replacement cells for rootrainers are also available 

Rapid Rootrainers

32 Cells Depth: 8cm Volume 115cc

Rapid Rootrainer books open showing plant roots

The shorter Rapid Rootrainers are best for annual plants that go out after the frost into shallow flower beds or hanging baskets. So this will be your bedding plants, salads and herbs. You might also want to do your onions in them. Not that onions really need a planting cell but if you have a problem with squirrels digging up your crops then arming your onions with a strong set of roots will make them harder to steal!

Smaller cuttings are also good in Rapid Rootrainers as early air pruning will help them establish.

Rapid Rootrianers replacement cells are also available 

Compact Rapid Rootrainers

Compact Rapid Rootrainers root trainer cells for planting seeds

20 Cells Depth: 8cm Volume 115cc

Compact Rapid Rootrainers are the same depth as Rapid Rootrainers but only 20 cells instead of 32 - for those tight on space. Perfect for urban gardeners growing in containers.

Maxi Rootrainers  

40 Cells Depth: 20cm Volume: 350cc

Maxi Rootrainer root trainer plant cells for planting trees

Maxi Rootrainers are ideal for broadleaved trees and plants destined for dry sites. So whether growing from cuttings or from seed a Maxi Rootrainer is perfect. The advantage is that they can stay in the Rootrainers for over a year if needed and will not become pot bound. So if you don't have the garden of your dreams yet but want to start growing an oak tree for when you do, plant in Maxi Rootrainers.

Do comment if there is anything more you would like to know about Rootrainers and follow us over on YouTube to learn more Haxnicks Rootrainers.

Check out our guides to Growing Sweet Peas and Growing Beans for more inspiration of what to do with Rootrainers.