Tomatoes - 2005

[tim]

Can't find my picture thing on poor rooting in 1/2 grow-bags on end so - start again.

It certainly made watering much more effective, but how do I prevent the roots all going down the sides of the bag & not filling more than 20% of it?? Grow them on much further - into bigger pots - before planting out? But they would then be much more leggy in my lean-to. Ina - have you ever cchecked out your root system?? = Tim

[tim]

[Derekthefox]

Forgive my naivete and possible ignorance Tim, but I have presumed that by limiting the amount of water during the growing period, the plants (tomatoes) would generate more roots . . .

I grow my toms in plastic pots which hold 1/3 of a large growbag, and when I empty out the pots in the winter, the growing medium comes out in one large lump due to the intense rootball.

Having said that, I must admit, before the flowering phase, I am not afraid to stress the plants by restricting the watering occasionally. So it may be that the root system is enhanced unintentionally.

I seem to struggle more with the odd plant that gets overwatered due to drips from the greenhouse roof . . .

[tim]

Yes - like it did in flat grow-bags.
But interesting - what, in your terms,  is limiting??  From the time ours have started fruiting, in 1/2 bags, they get anything from 1 - 2l a day, depending on the weather. = Tim

[ina]

Hi Tim, is this what you were looking for? I copied and pasted it for you:

What DID I do wrong??
« on: October 22, 2004, 19:21:03 » 

--------------------------------------------------------------------------------
Upended grow-bags - so much easier to water - no significant improvement in crop - much better ventilation & bottom trusses don't touch the ground.

But - as you can see in the cross-section - most of the compost was wasted. Why??

Presumably some fault in watering?? = Tim 

--------------------------------------------------------------------------------
compost.JPG (42.57 KB - downloaded 0 times.)

« Last Edit: October 22, 2004, 19:22:08 by tim »   Logged 



Hugh_Jones
Guest


   Re:What DID I do wrong??
« Reply #1 on: October 22, 2004, 22:02:52 » 

--------------------------------------------------------------------------------
tim, I suspect that it`s not a fault in the watering so much as the natural result of growing them in an upright growbag watered from above.  Planted in a horizontal growbag, which is only a few inches deep, the roots simply spread out in all directions and use all the compost.  However, in a deep bag watered from above the roots will still spread out sideways at shallow depth at first, and, having reached the sides (where the inside of the polythene will amost always remain moister than the compost in the middle), the roots will travel down them, keeping close to the plastic.  Had the bags been watered from below the roots would have tended to go downwards for the moisture rather than outwards, which is, of course, the principle on which the ring culture system worked.

You can see a similar result with almost any pot plant which is greatly overpotted at first in a plastic pot - the roots tend to go out around the edges of the pot, the compost in the middle starts to stagnate and the plant roots will only use it when the plant is in danger of becoming potbpound.  That is why you should only move up one or two sizes at a time when potting on pot plants. 

  Logged 

[ina]

I just want to add Tim, that by the time mine go into the upright growbags, the rooted stem is already very long and I mean very long so they go very deep into the growbag.

The seedlings are re-potted several times up to their top few leaves, the last container is a narrow, tall yogurt container and when it grew tall in that, it goes into the growbag, again up to its top few leaves. I guess the plant goes maybe 40 cm deep into the growbag and it grows roots on the entire length of the buried stem. This may avoid the problem Hugh mentioned of the roots growing out, only in the top part of the soil (when it's not planted in very deep) and then following the sides down, leaving the center unused.

[tim]

Thanks, Ina (and John elsewhere). Your bags are full of roots?? = Tim

PS I do start mine deep down & fill as they grow.

[ina]

No Tim, the bags are not full of roots but look nothing like yours either. When I take them out, the whole stem is full of roots but they are not as extensive as yours, often barely reaching the sides of the bags.

[tim]

But remember that these roots are only on the outside - as the cross-section shows. = Tim

[Derekthefox]

When I say 'limiting', I control the amount of water by period rather than amount. Thus I will soak the pots so the plant has copious water, but then will not rewater until the plant is definitely showing signs of dehydration, ie drooping leaves, However, I only use this method during the initial growing phase, as soon as the flowers start to form, I revert to regular watering. The downside? - yes, I do get the odd fruit with blossom end rot. Sorry I don't have any pictures.

[ina]

But remember that these roots are only on the outside - as the cross-section shows. = Tim

Yes, I realize that.

[tim]

Got it, Derek! Quite a gamble? 

BER? Last year, with the deep bags, was the first for years with NONE.  = Tim

[Derekthefox]

Most definitely a gamble, but I console myself with the reminder that this is a hobby (for me), not a profession, so the amount of control I can exert is limited. The successes are then celebrated far more ! ! ! Such is life . . .

[aquilegia]

I was thinking about this too recently. I grew mine the same way as Tim (Idea stollen from him, in fact!) and my plant's roots didn't fill more than the top 1/4 of the bag. I think it's the problem of watering from overhead. This year, I'll plant a long bottle with the top and bottom cut out in each bag to ensure the water gets under the plant.

[growmore]

Despite the grow bags being very convenient I wonder if the compost that comes in grow bags is really the best medium for growing tomatoes in..
I tried using the bags as they come one year and despite thorougly soaking the compost prior to planting I found that after no time at all it was a real task to get enough water to penetrate the compost without it running off the top before getting to bottom of bag.The result was quite a bit of blossom end rot in the crop that year.
So I tried big bottomless buckets the following year filled with growbag compost.The results were better. But I still found the compost compacted and water was taking a long time to drain into pots.
Tim I would say that from your photo the roots have gone to where the water was  readily available.  IE top of bag and sides of bag where the water had drained down more readily.The reason no root structure  in middle of bag was maybe that this portion of compost was not getting soaked. Perhaps some sharp sand mixed in with growbag compost would help this.
I have now reverted back to a more drainable medium for the
tomatoes. Blossom end rot does not seem a problem at all now.
I find Derek's method of letting  tomatoe plants droop before watering interesting.. Jim

[aquilegia]

Growmore - in 2004 I grew mine in old compost bags, with a mix of 50:50 soil (clay) to homemade compost. I found it held water much better than the previous year, where I grew them in pots with growbag compost. The growbag compost dried out really quickly and never got wet again (water ran straight through it). I didn't have this problem at all last year.

[Derekthefox]

I don't want to be held responsible for lots of failed plants next year ! ! !