[ryetek]

In previous years we have only grown outdoor bush tomatoes with reasonable success. This year is our first attempt at growing cordon type tomatoes for the new unheated greenhouse.

We haven't been very adventerous and we only have Alicante and San Marzano varieties in addition to the Garden Pearl outdoor bush tomatoes. However we seem to be having a few teething troubles but only with the Alicante variety and would appreciate some advice please.

Firstly some of the underside leaves are going purple especially at the base of the plants. The top of the plants look very green, bushy and healthy. Googling around tends to imply over watering and/or cold conditions. I'm currently bringing the plants in every night and putting them out every morning so I'm not sure about the cold. However I may be over watering but they only get the same as the other varieties. How do I prevent the leaves from going purple? Is there a cure for the plants with purple leaves?

Secondly the stems are really thick (as thick as my little finger) but the plants are still quite tall at around 8 to 10 inch. Is thick stems a good or a bad thing or just common to Alicante?

Also I'm worried about the plants becoming pot bound as they're currently in 3.5 inch pots. Could this be causing purple leaves due to poor nutrient up take for example? I do want to get them potted on to 12 inch pots but that would prevent me from bringing them in on a night.

Unfortunately I'm not at home at the moment otherwise I could provide some pictures. However I would appreciate any advice on any of these issues.

Thank you in advance.

[shokkyy]

Oddly enough, Alicante, San Marzano and Gartenperle are my three varieties of choice for growing in my unheated polytunnel and hanging baskets (GP, obviously). I've always found all three to be enormously productive and very good robust plants. In fact, if you don't keep on top of the sideshoots on the Alicante and SMs, they'll turn into triffids.

I would normally associate purple leaves with getting a bit cold. We are having some very odd weather right now. I know you say you're bringing them in overnight, but is it possible they might be getting a bit chilly first thing in the morning or last thing in the day, just after you put them out or just before you bring them in?

And I would say 3.5 inch pots were a bit small for 10 inch plants. You don't have to move them on into a big 12 inch pot. I normally move them on once to an in between size, going from 3 inch to 4 inch before moving them into their final position. You don't want them to get pot bound. I'd say thick stems were a good thing though, much better than thin spindly stems.

[mumofstig]

My one plant in a small pot, which has always lived on the windowcill, has purple leaves as well - the plant has used all available nutrients from the compost by the time it's that tall.

Move into larger pots or cut down placcy milk bottles, if you are feeling frugal 

[ryetek]

Thank you for the replies shokkyy and mumofstig.

shokkyy, strange how you grow the same varieties as we've choosen to try. It's possible the plants may have got a bit of a chill when I put them out on a morning. On a couple of occasions it's been 8c in the GH but we've both had to get off to work and have not had any choice other than to leave them in the house. That said it does not appear to have affected the other varieties though. I will re-pot on in to 5 inch pots which we have plenty of.

mumofstig, it may well be the case that the compost has no nutrients left in it. I do like the milk bottle suggestion. Never thought of that before 

When I re-pot them on do you think I should give them a 1-off feed also?

[mumofstig]

A weak liquid feed would do no harm 

[ryetek]

Thank you mumofstig. I'll do that and ensure it's a weak mixture.

[Headgardener22]

You don't want them to get pot bound. I'd say thick stems were a good thing though, much better than thin spindly stems.

I agree that you don't want them to get too pot bound but I had heard that limiting the roots (a little) helps to encourage flowers and that feeding them too early discouraged flowers. As flowers are what you want, and you shouldn't plant them out before the first cluster of flowers, I would suggest potting them up into 9cm pots, that would probably give them enough fertiliser to avoid having to feed them.

BTW mine are now out in the unheated greenhouse full time. The temperature varies between 25C and 8C (which is a little cold I know but I can't move them all into the warm

[Totty]

You don't want them to get pot bound. I'd say thick stems were a good thing though, much better than thin spindly stems.

I agree that you don't want them to get too pot bound but I had heard that limiting the roots (a little) helps to encourage flowers and that feeding them too early discouraged flowers. As flowers are what you want, and you shouldn't plant them out before the first cluster of flowers, I would suggest potting them up into 9cm pots, that would probably give them enough fertiliser to avoid having to feed them.

BTW mine are now out in the unheated greenhouse full time. The temperature varies between 25C and 8C (which is a little cold I know but I can't move them all into the warm

Sorry but I totally disagree. I make sure the toms have NO flower trusses when planting out. If they start forming before I plant them out, I'll nip the truss off.

You want the plants to concentrate on getting roots established and growing strongly before they start putting the energy into flowering and fruiting.
 I would pot them on, give them a weak feed and nip off any flowers forming now, so that the plant forces out new roots for nourishment and has to grow with vigour in order to produce more leaf and another truss so that it can do it's job (create seed), by which time it will be time to plant out and they will fly away.

Totty

[tribs]

Interesting. I too thought the general advice was to stress them a bit by keeping the pots small so they'll flower sooner. I've never heard anyone advise removing the first trusses on tomatoes before. I may try it with one of my plants this year. I've got loads.

[Totty]

In an ideal world we would sow seed at the perfect time to allow planting out when the weather is warm enough and the plants are growing strongly, nearly filling the pots with roots and just about to start thinking about throwing out a truss. In reality though we all sow things a bit to early and to get timings perfect with our climate is impossible.
IMO I would rather sacrifice the first truss and have a better established plant to crop well throughout the season.
Each to their own though, everyone does there own thing to good effect in this game [img]

Totty

[ryetek]

Thank you for all the replies.

Last night I decided to pot them on and also give them a really weak feed. I put them in to 5 inch pots in order that I can still bring them in on a night. Our GH is regularly dropping to between 4 and 6c during the night at the moment. The plants currently don't have any flower trusses on them at the moment so I had nothing to nip off. Rightly or wrongly I'll see how it goes.

[Stree]

With regard to planting out and flower trusses, I intend to plant some in Levingtons Giant tomato planter bags this year for in the greenhouse.
Most of my plants are 8 to 11" high and I have been  waiting for the first flower trusses to set before planting out. The reason for this is because this is what the instructions on the bag say.........Plant out ONLY  when first flower trusses set.
The reasoning behind this is that if you plant out before then the extra nutrients in these bags ( inbuilt nutrients and fertilizers), will promote root and foliage growth at the expense of crop production.
An ordinary grow bag does not contain anywhere near the same level of food, the Levingtons are specifically for growing tomatoes and the mix is tailored for this.
I am more than happy to go along with this advice and really find it hard to imagine why cutting off the first truss can help in anyway.
Not saying its wrong, I do not know enough yet to reach an informed conclusion, but it goes against all the advice I can find.
Still. whatever works. We all do things differently and I might even give it a go with some plants in ordinary compost.

[A Reyt Tayty]

All my toms are now in the unheated greenhouse and have been for about a fornight. They seem quite happy. Even the smaller wrecklings of the litter are now picking up really well.

[Totty]

Plants that have better root systems will be able to take up more nutrients, resulting in bigger, more desiese resistant plants that crop heavier.
 If a plant is in a pot and its used most of the nutrients up, then starts flowering, itis actively seeking potassium which will aid its fruit and flower development, the pot lacks nutrient as the plant has been feeding and getting the nutes washed out for some time, so the first truss, if formed while the plant is in a small pot, will be weaker and smaller. The time it took to form this weak truss, it could have been growing root and foliage to support a long growing season.
The key is to have smaller plants to plant out in the first place, not plants struggling to get nourishment.

Totty

[Headgardener22]

It only goes to show that there probably isn't a "right" way, only one that suits you. I have found in the past that planting tomatoes before they have the first truss of flowers showing tends to mean that the first truss is higher off the ground so there are fewer trusses before the plant has to be stopped because its reached the top of the greenhouse.

But then again, I've found that some varieties (red berry in particular) grow a good two feet before the first truss, and that's too big to keep in a pot (and digging a hole two feet deep is into solid clay).

If you've enough plants, try different things then some will grow better than others (this year).