Kitchen Garden Forum

I planted most my tomatoes outside 2 weeks ago and protected them with large square mineral water bottle cloches, some made of clear plastic and some made of pale blue plastic.
I've noticed that compared with the few tomato plants I still have indoors on my window sill, the leaves on the outdoor plants are a much paler green and don't look quite as healthy as the plants inside.
Can the plastic cloches be having that effect on them by filtering out sunlight in some way? I'm puzzled because I don't think leaves on greenhouse grown plants are affected in this way and the leaves on the single plant still in my mini greenhouse with the plastic cover still has darker green leaves. Any suggestions for the cause, and how to cure it?

Dear Primrose, have they got any ventilation, i was just wondering if they were getting to much humidity in the bottles.
It can't be the cold, as they are like us, and turn a bluey colour.

I wonder if you have a point or they're suffering from a slight lack of oxygen? I've slipped the bottle cloches over the thin carbon lead pole to which I eventually tie them, which keeps them anchored when it's windy. There's a slight air gap in the remainder of the bottle top hole but possibly not enough. Perhaps I should remove the cloche bottles during the day for a while and return them at night to see if the leaves green up.

Hello Primrose
Did you harden them off before planting out? They may have been set back slightly by a sudden change of growing conditions. Keep your fingers crossed and all should be well after they have settled in.

John

I hardened them off for several days outside during the day, but it was during that spell of really warm weather, so I suspect they didn't really have a chance to get acclimatised to the current temperatures we're experiencing which are probably more normal for this time of year. I'm beginning to find that this global warming we're experiencing, although it's nice to enjoy early warmth, is going to cause we gardeners a lot of headaches going forward, not knowing how best to nurture our seedlings to take account of wildly fluctuating temperatures in short spaces of time. I did throw a handful of chicken manure pellets along the growing area and wonder whether these, combined with the composted manure which was dug in in late winter has proved over-rich for the roots.

again primrose: why are you doing things so early? outside tomatoes should really only go planted outside in june at earliest in british isles.

i would say the leaves are gong paler , due to getting acclimatised to new conditions, but in a cool enviroment. If you see them start to take stock and grow. i would give them a nitrogen boost. but i am guessing.

my tomatoes in glasshouse in intermediate pots went a bit paler. i gave them a dose of miracle grow. they have gained a bit of colour.

Of course if u want to be strictly oragnic then, manure tea would probably do the same trick.

forget the day time temps. work by the night temps with these 'hot-type' plants.

cloches do 'sweet F all' regarding min night temps. they protect plants from wind primarily.

polytunnels the same.

Dear Dewwex, i have to slightly disagree with you over the cloches and night time temperatures.
It must keep slightly warmer under the cloches at night because the soil gets warmer during the day, so lets a little more warmth out during the night.
I know this wouldn't be a huge difference, but one that i would have thought would be more pleasing towards the plants.

Hi OH,
To a great degree Dewwex is correct. Temperatures inside a cloche type that Primrose is using the night temperatures would be the same. Where cloches score is that the plant will not receive any direct frost should one occur. Plants will survive quite low temperatures but cannot withstand frost directly on their leaves. Certainly cloches are a very useful tool in the gardeners armoury as they protect against the wind, frost and to a very great degree pests.
Certainly the recent night temperatures have been quite low and in fact too low for Tomatoes to really thrive.
The colour of the material can cause certain things to be filtered out of the spectrum. Some years ago a Japanese University did quite a deal of research with light filters but the only snag is that I cannot remember which Uni or the outcome of their experiments. All I can remember was there were some striking examples.
JB