Bendy Tom Seedlings!!

[Sparky]

My tomato seedlings camthrough a couple of days ago and the true leaves are just begining to form.  The stems seem a bit bendy tonight though and i am wondering if i am over watering them?!?  Should i let the compost get a bit drier instead?

Also when do i need to prick them out?  Am i ok to do it now or do i need to wait til the leaves are fully formed?

Sparky

[Sparky]

[Mrs Ava]

ooeerr....overwatering is bad bad bad.  I let the compost almost get dry, well, I judge when the compost is looking dryer before I water again.  If they are getting floppy and keeling over, you might have damping off disease, expert needed now please, but I think it is a fungal disease which spreads when there is poor aircirculation around the seedlings.  Or of course, it could be that there is lack of light so they are growing tall and spindly looking for light.  If I were you....I would prick them out into pots and plant them nice and deep, right down to their seed leaves so that the 'spare' stem can make roots and get them somewhere nice and bright.  Hope this helps.  :-\

[Hugh_Jones]

It may indeed be the result of overwatering, if so drying them off might help but if the seedlings are newly emerged the root systems may be damaged.

If it is `damping off` fungus, then the stems of the seedlings will look very thin, or `pinched` at soil level when they keel over, and any such should be removed and discarded immediately.  As the disease spreads very rapidly over the soil surface, any not now affected should be potted up singly as soon as possible.  If you have any Cheshunt Compound, water the compost with it (if you haven`t got Cheshunt Compound then get some - it is an invaluable stand-by when you`re growing seedlings in a confined space).

And whatever you do, don`t touch the stems.

[aquilegia]

Mine went rather leggy, so I moved them to somewhere cooler. Also make sure they have plenty of light. If they are bending towards the light, just turn them round every day to keep them straight.

Prick them out when the true leaves are forming and hold them by the seed leaves, not the stem. Plant them so the seed leaves are just above the surface of the compost.

[cleo]

Not easy to explain but in time one gets the `feel` of a pot or tray,the weight gives an idea of whether it needs watering or not. And look of course as well.

Stephan.

[Sparky]

Thanks guys

I don't think they look pinched so hopefully they'll be ok!  If not i've still got some seeds left so will have another go.  Didn't realise you could cover them up to their seed leaves when you prick them out, should i be doing that with my other seedlings too?

Sparky

[rdak]

I think John said it can be done with marigolds. Had a quick google and
http://www.plantea.com/seedstart.htm says that you can do it "For tomatoes, broccoli and other cabbage plants " However, that site also recommends fertilizer once seedlings have their first true leaves, so perhaps the advice be taken with caution!

http://www.floridata.com/tracks/peppergallery/start_pepper_plants.htm says "It doesn't matter whether or not you bury pepper and eggplant stems, but many other seedlings should not be buried deeper than they were in the original pot."

http://www.mrs.umn.edu/pyg/tips/soil_planting/tip_1115.shtml recommends burying seedlings, but doesn't mention any specifics about what types.

[Sparky]

Perhaps i'll try a few and see what happens?!? :-\

Thanks for looking though!

Sparky

[Hugh_Jones]

The seedlings which you can plant deeply are those which make adventitious new roots on the buried parts of the stems, and tomatoes are a prime example of this.  If you inspect the stem of a growing tomato plant carefully you will see that just above soil level there are numerous small nodules which are the beginnings of new roots, but they do not usually develop unless compost is added to cover them. Indeed, one of the advantages of using the `ring culture` method is that one can plant in only a small quantity of compost initially, and then top dress the rings regularly with an inch or so at a time, resulting in the production of new layers of root to add to the vigour of the plant as it grows. Using this method I regularly used to run tomato plants up to 12 - 15 fully developed fruit trusses.

This process, however, only works with a small number of plant types (particularly the solanum family), brassicas will stand deep planting, although I question whether any adventitious roots are thereby produced.  In most other types of young seedlings deep planting is an invitation to damping off and stem rot fungi

[john_miller]

  It is advantageous to bury tomatoes because they will root through the hypercotyl, the part of the plant between normal roots and the cotyledons. Most other vegetables don't. However, with these other plants, if you do bury the hypercotyls you will increase the contact area between the tender tissue and the soil. This may allow more access for opportunistic infections such as the damping off fungi, especially if extra damage results during the burying process.

[john_miller]

  You must type a lot quicker than me Hugh!

[Hugh_Jones]

And there was I thinking you were trying to upstage me with big words. Put the typing down to years of practice, John.

However, purely as a debating point, how certain are you in restricting adventitious root formation in tomato plants to the hypercotyl?  In using the `ring culture` method over many years, I would regularly top dress to above the cotyledons, and roots would still form.  Indeed, to get my plants up to 15 trusses I used to take the stems down from the canes at 10 trusses, lay them horizontally for 3 or 4 feet, and then fasten them up the next cane. Invariably the stems would slide slowly subside to ground level under the plant top weight, and I usually found that where they touched the bed medium more roots would form.

And that reminds me, I completely forgot to include cucurbits among the list of those plants happy to make adventitious roots - must be getting forgetful in my old age!

[john_miller]

  I certainly didn't mean to infer that adventitious roots were confined to the hypercotyl, Hugh. Apologies if I misled anyone as well as yourself.
 Possibly because I grow all my cucumbers through black plastic I haven't ever noticed (may just not be paying enough attention though) adventitious roots growing from them. I have seen Cucurbits producing roots where the nodes touch the ground, but this is not true adventitious rooting.

[Hugh_Jones]

Well John, I always grew my cucumbers in the old fashioned way - on a mound on top of the bench over the hot water pipes - and followed the old practice of adding an inch or so of soil over the mound every time the roots appeared on the surface.  Over the growing season I would add four or five inches to the mound, but when I cleared the plants out in the autumn the stems always appeared to be rooted into the top layers of soil surrounding them.

I also grew my marrows outdoors on mounds in the same way, with the stems supported on a horizontal frame, and again, after several top dressings, the stems always appeared to have rooted out into the new compost.

Maybe this wasn`t adventitious rooting in the true sense - I don`t know - but it certainly grew fine cucumbers and marrows.

[john_miller]

  Of that I have no doubt Hugh. I will do some checking whether they root adventiously but if it works in your situation it is simply academic and fun to find out.

[The gardener]

One for Hugh!

I take your point of increasing the root system by 'mounding' the soil at the base of the plant/s

But I use the mound method for a totally different reason, I find it reduces the risk of 'neck rot'

[Hugh_Jones]

Well, of course it does. But as the point which John and I were discussing related to adventitious rooting the question of neck rot didn`t arise, and in any case I would have considered it an insult to remind John of something so obvious and well known.

Neck rot usually occurs when the soil around the neck is allowed to remain cold and wet - as when the plants are grown on the level or in growbags.  The effect of the mound is to drain surplus water from around the neck instead of allowing it to lie, which is the other reason why every serious grower of cucurbits always used the method until the advent of growbags induced indolent methods.

[john_miller]

      Instead of waiting to check with my local adviser Hugh, which was my original intent, I had the bright idea of googling (is that a verb nowadays?) adventitious roots. A topic as equally tortured as photoperiodic response in potatoes I think! What I read in some papers contradicts others. My definition of adventitious roots is too restrictive (simply applying to plants that had root buds along the aerial stems).
 Apparently, according to some papers, adventitious roots can be produced by plant roots too, especially in response to stress (as in your cucumbers and marrows it would seem)  while others indicated that more plants than I realized can spontaneously initiate roots simply by having their stems in contact with the soil.
 Adventitious roots are botanically different from ordinary roots, being more open structurally, as they are used by the plant to increase gaseous exchange should the regular roots be restricted in their ability to do this. This is why your cucumber plants produced roots as you buried the stems.  

[Hugh_Jones]

Of course, John, it used to be a fairly widespread belief among cucurbit growers using the mound system that covering the stems resulted in the production of new roots, and, of course, where such an ability exists in a plant the propensity to do so will increase when the plant is under the stress of producing a crop.  The same principles were used in the regular topping up of tomatoes in the ring culture method.  My doubt (mainly resulting from your reference to adventitious rooting through the hypercotyl) was merely as to whether such roots - often initiated above the level of the cotyledons - were true adventitious roots, and I think that we are now both in agreement that they probably are.