Rootrainer substitute?

[Vinlander]

I need to make tall narrow pots that can produce a tight matrix of seedlings in Feb to fit heated trays under LEDs.

I still use beercan Alu (free once you've bought the 7% contents) to make 35x35x90mm 'tallboys' but I was looking for something tighter, easier, quicker and less lacerating.

It occurred to me that fitting clip-top trunking in my sunroom was quite expensive but a 2m length could make 20+ tallboys with sides that would slide out nicely.

The 16x16mm is probably too fiddly but the 25x16mm is exactly right @ £1.68 per 2m.

I may even invest later in the larger size of 38x38mm (sadly not available from Screwfix) because it works out a similar price to the equivalent Rootrainers and similar P&P (if you don't have a big DIY nearby) Oh, and it's about, say, 1000 times more durable?

You have to find a way to stop the soil falling out and let the moisture in from below (capillary matting). I use several methods and haven't settled on one yet.

You can buy a bit of 2-3mm Alu mesh pretty cheaply to make springy shallow U's to fit in the bottom. Expanded metal is good, I have a very similar-looking green plastic equivalent called "shade mesh" that's just stiff & springy enough (though I haven't seen it available lately). Metal lathing is good but don't blame me if it slashes your fingers.

Bits of green kitchen scourers are usable if you pack the compost a bit to push the U against the sides - or you could put something across the bottom to hold in whatever you use.

I've just started using this method so if anyone else has tried it your experience would be useful.

Cheers.

[Vinlander]

[Tee Gee]

You have to find a way to stop the soil falling out and let the moisture in from below (capillary matting). I use several methods and haven't settled on one yet.

Have you considered Oasis foam?

You could push the trunking/ tubing into it like a cake cutter into dough and this would create a moisture retaining plug that would hold in the compost a suck up moisture from you capillary matting.

[InfraDig]

Sorry, a dumb question! What makes a rootrainer a rootrainer and not a pot? I have been considering using Benecol type tubes, but really am not sure whether I should have slits in the sides, or bottom. Hence the question!!

Thanks.

[Tee Gee]

What makes a rootrainer a rootrainer and not a pot?

I don't really know myself but I look upon root trainers as the 'flat pack' of the gardening fraternity.

That is they come flat, are connected together to form a container then dismantled after use!

Although I have some I do not particularly like them because of their flimsy connecting system particularly after they have been used a few times.

Then I find if I do not use the full complement of sections in the carrier frame they are quite unstable.

I am keeping a watchful eye on Vins suggestion as I think he might be on to a good cheap alternative.

[InfraDig]

Is it a hole in the bottom that makes the difference? Does it need holes or maybe grooves in the side? Is it like an airpot?

[InfraDig]

Mmmm...

This is what Wikipedia has to say....

"A root pruning container is an aid to the cultivation of young plants and trees in nurseries. There are many different designs of pots that will train the roots. One example is a truncated plastic cone in which a seedling is planted. There is a drainage hole at the bottom and the main tap root tends to grow towards this.

What this achieves is to encourage the roots the grow a denser system of root hairs. How it does this is to have the pots designed so as to air prune the roots.The advantage is when the plant is planted into its home environment it has a stronger root base to start with.[1]

When polythene bags are used instead, this root tends to go through the bag into the ground and is then broken off when the tree is moved for planting. The other roots are insufficiently developed to cope with the shock caused by this and so the tree's chances of survival are reduced. The root trainer is mounted in a stand above ground so that, when the tap root emerges, it is dried by the air. This air pruning causes the root inside the pot to thicken with stored carbohydrates which will support vigorous root growth when the plant is put into the ground.[2] The other lateral roots of the plant grow to compensate for this and so a stronger root ball is formed which improves the sapling's chances.[3]

When raising multiple seedlings, the root trainers are commonly placed in trays or racks. The size of each trainer depends upon the species but, for broad-leaved trees, the capacity will be about a cup. Vertical ribs inside the trainer are positioned to train the roots to grow downwards and so prevent root spiralling."

They seem to be talking about airpots, but also mention vertical ribs....

[Tee Gee]

Root trainers in use and you can see the ribs as mentioned in the wiki article.

[lezelle]

Hi Ya, I am trying to replace my 22cm root trainers due to them breaking at the hinge but the price seems to be rather excessive. I only want the books as I have the trays already. All I have seen are the smaller ones or the whole lot including cage. I am very interested in alternatives and your idea vin seems like it may be the thing. Could you please tell us the name of the product clip tube? where you purchase it? and possibly a photo of it so I can see it exactly before purchase. I would be most gratefull if any one could in the mean time point me in the right direction of trainers (22cm) if possible. Thanks to all and happy gardening

[InfraDig]

www.garden-roots.co.uk might be selling what you want.

I have only just found them, and know nothing about them!!Caveat emptor!!

[squeezyjohn]

www.garden-roots.co.uk might be selling what you want.

I have only just found them, and know nothing about them!!Caveat emptor!!

Haha - I just found that site and ordered a load of replacement inserts this morning.  Must be that time of the year!

at £4.99 a pop they're still quite expensive - but I have to say there's something about those rootrainers which just works to get a great root system in a tiny space and I swear by them.

[Vinlander]

The smaller "25mm x 16mm" and "38mm x 25mm" versions I'm most interested in can be found on Google by typing "mini trunking" plus the size as left.

Typing "Mita MT5 3m 38 x 38mm Mini Trunking" will find the bigger version - that's much harder to find.

That garden-roots site is a good find... Buying the flimsy books at £3.99 for 32 cells (£16 for 128) is nothing like as bad as paying another £18 for the 4 flimsy propagators that come in the kit. 

Even I might be tempted - except I can't overcome my abhorrence for any device that is made with a material so inadequate to the task that it is already landfill - it just doesn't know it yet  .

I've said it before and I have to repeat myself - I would grudgingly pay 50% more if they made them in 1mm propylene. I would buy them today if the price only went up by how much more it would cost them (1%?) - and their profits would probably double.

Hell, I might even buy them today if they cost the same but were made from the plastic they use for sausage trays - not the mushroom-tray rubbish that matches what they use now.

Cheers.

[InfraDig]

Amen to that!

[lezelle]

Hiya, thanks for the effort. I would like 22cm deep to match what I have already. I have found the sites selling them but they are all 8 and 12cm. I have the trays and only want the books as the trays match the size of the books. I must admit they have gone a bt expensive so alternatives are on the list. I like them but maybe it's time to move on. Cheers all

[squeezyjohn]

That trunking stuff looks like a good idea - I'd be interested to see if the roots go down as nicely as they do in rootrainers without the ribs in the sides of the modules.  I've tried something similar with cardboard tubes in the past and the roots didn't develop as well.

The only down side to this type of arrangement (including real rootrainers) is how dreadfully fiddly they are to fill with compost without loads of air pockets.  I find I can only do it successfully if using a very fine compost that is very dry otherwise it clumps and causes problems.

[peanuts]

i've had my root-trainers for years, and a long while ago the hinges broke at the bottom, but it doesn't seem to make any difference to the ease of using them. In fact, they are easier to put away after I've used them, packed flat, and  next time I want to use them I just slot them together again in the cradle. 
I often  use only some of them.  It is just necessary to fill the cradle first with all of them, then put compost in the ones you want to use, leaving the others empty, to give stability.

[Vinlander]

I've just added a funnel template to my gallery. Print it and use it to cut out the funnel I use for filling my 2.5x10cm 'pots' (that allow me to get more seedlings under a light). You'll have to get the magnification to suit your printer and your cells.

The better the fit the easier it is to encourage the mix to go in without caking...

It's not difficult to cut and tape the template to shorten 2 sides for a better fit in cells that are rectangular eg. electrical trunking.

Will also work with rootrainers and other substitutes.

Cheers.