Problems with tomato plants

[helena]

This is my first greenhouse and I'm fairly new to veggie growing so not sure if this is normal or not.

I've got some tomatoes planted in an unheated greenhouse (they're about 8" tall) but I have noticed that the lower leaves are starting to turn yellowy green. They all started out a nice dark green colour Do you know if this is a lack of fertiliser or what I should do to try and counteract this.

Some of my other seedlings (brassicas) also seem to be going slightly yellowy.

Any help would be appreciated.

[Norm]

From what I understand, there's usually only about 2 weeks nutrient in potting compost. I give everything a half dose of tomato feed once a week after the first fortnight and just keep the soil damp for the rest of the time. Always works for me.

[rustylady]

Sounds as if they need feeding. What size pots are your tomato plants in? They need potting on into bigger pots regularly - the addition of fresh compost and nutrients keeps the plants healthy. If in spite of this they look a bit poorly give a foliar feed - works wonders. Also keep an eye on the temperature, as if the air is cold and the compost is wet the little dears will suffer.

[helena]

thanks for the advice - I shall give them all a feed tomorrow and if that doesn't pick them up I will try the epsom salts. (Where do you buy epsom salts from tho?)

[bramble]

Might you be overwatering them. Its a common mistake to make when starting off. Just keep the compost slightly moist rather than wet.

[vegman]

Dont know in which part of the country you live but Tomato plants dont like fluctuations in temerature. It may be too cold during the night,

[helena]

I'm in the north of england so it is entirely possible that the cold has got to them. They are in an unheated greenhouse. Some of the other seedlings seems to have got cold as well so I've had to invest in a parafin heater for the really cold nights.

They seem to have picked up a bit with the feed and there are flower buds visible. Wasn't expecting them this early.

Thanks for all the advice.

[Flummery]

I'm in the north too Helena and I still bring my toms in at night from my unheated greenhouse. It's only a walk to the end of the garden for me, so I'd rather not take the chance. Different, I admit, if you need to travel to an allotment.

[Cutecumber]

In my experience, the leaves of tomatoes that are kept too cold go bluey purple, so I don't think this is the problem.

An 8 inch tall plant is likely to be at a really strong growing stage (think puberty!) and wants nutrients - a regular, balanced fertiliser (at this stage) could be worth a try.

[has-bean]

mines 4-5 inches high and in 3-4inch pots an a few starting to go yellow which worries me as offered some to friends. I think is prob overwatering but will give em a quick dose of tomorite in the morn and maybe get em in pots and growbags asap. Any advice most welcome. Mine in unheated greenhouse too but lowest temp now is about 8 deg. very hot during day tho and i am out a lot with worki