Topic: Leggy tomato plants :(

[fitzsie]

This is my first time at growing tomatoes from seed, Marmande and Fioritino (sp?) which started off well but the plants seem to be growing so slowly, and when they do it is upwards rather then outwards !! At the momennt they are in my porch which has sun for a good part of the day. I only have a 4 tier plastic greenhouse which I will put in when (if) they get bigger.
I've just had my parents round and my Dads first comment was, "they're very leggy". What am I doing wrong? When I potted them on I made sure the soil was higher up the stem taking off the first leaves. Is it because of the cool weather we have been having? Any tips gratefully received.

[Deb P]

Plants usually get leggy from inadequate light....so that is the first thing I would check. Tomato plants like to be kept over 10 degrees at all times too, the undersides of the leaves look slightly purple if cool temperatures are contributing to the slow growth. I would also consider giving then some seaweed tonic to boost root growth and general vigour, they don't usually require feeding with tomato fertiliser until the first flowers appear so don't be tempted to feed too early. My tomatoes have really only started taking off since I repotted them last week, so you could consider potting them on into bigger pots if the roots have filled the current pots.   ;D

[fitzsie]

I only potted them on last week where they had been spending time on my kitchen window sill. No purple leaves although it does get cool at night in the porch. Haven't used tomato fertiliser as I know I have to wait for flowers. Will look at getting seaweed tonic as I think the "general vigour" of my plants is sadly lacking.

[Borlotti]

You have sun in your porch.  Lucky you, but we have had sun for the first time this weekend.  My tomatos are very slow this year, not even leggy yet, hopefully they will come on when it gets warmer.  They are in my leanto which does get very hot when we get sun.  Not going to pay 79p for one plant at Morrisons, so will hope that mine recover when the weather gets warmer. Not going to put them on the allotment, but will put in pots in front garden when bigger as they love the sun out there, if we get any this year.

[SueK]

Really sympathize with the last two comments, my seedlings are on a go slow as well.

[martinburo]

Aluminium foil at the North side of the pot helps. Eat more chocolate  ;)

[Coastie]

I had leggy tom plants at the start of the year and bought a light lamp and repotted them lower in the compost.  This worked for me and I have them out in the greenhouse now where they are flourishing and the first sets of flowers are in full bloom.

[AdeTheSpade]

Every year, I always grew my tomato plants on the conservatory windowsill and I didn't put them in the (cold) greenhouse (in pots) until late May.  They were always leggy, but did produce plenty of tomatoes. 

This year however, I started them as usual on the heated propogator in the conservatory, then after they'd germinated and been potted on, every morning I've put them in the greenhouse, and every evening brought them back in the conservatory, just to keep them a bit warmer overnight as the temps have been so low.  I'm just starting to leave them in the greenhouse overnight if it's not going to be too cold.  As a result, they are not leggy at all, but really compact, so I'm sure they must prefer the extra light they get from the greenhouse during the daytime.

[Ian Pearson]

I think high light levels are especially important for tomatoes. Even in a greenhouse, I think they do not get full spectrum daylight, and suffer as a result.
You don't get suntanned through glass, which proves that part of the spectrum is excluded, so i reckon it's good to get the plants outdoors during the day whenever possible. Movement from the wind also toughens up the plants.

[picman]

Light and more light ... I tried watering with a very dilute organic seaweed solution this year ,I seem to have greener stronger plants , chocolate fingers crossed....

[BarriedaleNick]

I think high light levels are especially important for tomatoes. Even in a greenhouse, I think they do not get full spectrum daylight, and suffer as a result.
You don't get suntanned through glass, which proves that part of the spectrum is excluded, so i reckon it's good to get the plants outdoors during the day whenever possible. Movement from the wind also toughens up the plants.

Glass absorbs a lot of very shortwave UV light but passes most other light - From wiki "Ordinary window glass passes about 90% of the light above 350 nm, but blocks over 90% of the light below 300 nm"  Plants dont make use of UV in terms of absorbtion of light by chlorophyll which absorbs mainly red and blue visible light (and reflecting green).  Plants under glass or plastic get all the light they need to grow porperly which is why most toms etc are comercially grown under glass.
However plants grown indoors are not subject to any environmental stress and are held at near constant temp which is why they get leggy.  Toms subjected to a bit of cold, a bit of temp  variation and to wind stresses will toughen up and produce much stronger stems.