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How to water greenhouse tomatoes properly?
ZeroZero1
Posts: 577
Hi All,
I have been growing tomatoes for a few years now and have made a few mistakes. I have had split tomatoes, blossom end rot and leaf curl.
In the present incessant heat I have been watering my pots twice a day. I have realised that I don't really understand how to water them
With a standard pot plant, I usually wait for the soil to feel dry to the finger, then water. With tomatoes, doing this feels too late and the plant shows obvious signs of stress.
The pots are large - say 4 gallon, and the plants are large too at about 6ft. They have maramande type tomatoes, one of which is Gigantum (T&M) and the rest are standard maramande
How does one ensure that they are not under or over watered?
I have been growing tomatoes for a few years now and have made a few mistakes. I have had split tomatoes, blossom end rot and leaf curl.
In the present incessant heat I have been watering my pots twice a day. I have realised that I don't really understand how to water them
With a standard pot plant, I usually wait for the soil to feel dry to the finger, then water. With tomatoes, doing this feels too late and the plant shows obvious signs of stress.
The pots are large - say 4 gallon, and the plants are large too at about 6ft. They have maramande type tomatoes, one of which is Gigantum (T&M) and the rest are standard maramande
How does one ensure that they are not under or over watered?
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Posts
I now grow them in the border in my greenhouse, but I used to grow them in 22L pots in the g/house and I kept to a routine of giving them something every other day.
Tuesdays they get tomorite, Friday they get seaweed extract and in between plain water ever other day. But if it's extra hot, they may need watering every day.
I've got a cucumber in a 22L pot that is doing very well. In this weather I'm giving it 6L in the morning and 6L in the evening.
I don't follow the - only water when the leaves are drooping - routine. If the leaves are drooping the plant is stressed, which is not good for the plant.
Billericay - Essex
Knowledge is knowing that a tomato is a fruit.
Wisdom is not putting it in a fruit salad.
Try and cool the greenhouse down.
I'm not sure if you're growing them in pots but that's not a great idea in a green house. If it's drooping and you can't water it more often then you're probably being greedy with how many tomatoes you're trying to get from it (I'm always too greedy).
I created some drip feeders from old Appletiser bottles (other brands available), drill 2-3 holes in the lid and shove it into the soil. Usually drips out over about 12 hours. I find this to be sufficient in addition to my once-per-day watering effort (I fill it up at the same time I water them, in the evening).
The leaf rolling is most likely heat rather than watering. Blossom end rot is the classic sign of too little water, split skins means inconsistent water, blight means too much water.
The trouble is tomatoes are tricksy things - easy to germinate but actually not very easy to get good fruit ripe, because 'rules' don't work very well, IME. What is right in one greenhouse one year won't be right in another place or a different year. My neighbour has a very large polytunnel with quite a stable temperature. Mine is tiny and it gets very hot and very cold. So we have to do things differently. Generally cherry toms are easier than the big ones. But I'm afraid it's a trial and (lots of) error process to find a method that works for you most years and time to gain enough experience to be able to see when things are going awry and correct it. I'm getting better at it, 8 years in, but still haven't got a sure fire set up I'm happy with.
So I suggest you try a few different things, different sized pots, growing them in the ground, even outside (working well this year - last year, not so much). Drip watering, twice a week watering, watering the greenhouse floor on sunny days (cools the air), gravel trays, ring culture, different potting mixes and some day all the stars will align and you'll get a perfect crop. Or at least that's what I keep telling myself.
“It's still magic even if you know how it's done.”
This year I have grown Maramande (Seedparade) and Gigantimo. I find maramande to be excellent, meaty, well flavoured and large. I have grown some in the greenhouse and some outside. I water twice a day. Both are doing well except the garden ones have flopped having outgrown their stakes - at about five feet high. Plenty of green fruit on all trusses sometimes four large toms per truss and several trusses per plant, even with pinching out
I picked my first tomato today, a gigantimo, it started to turn colour and I found it haf blossom end rot - salvageable. The Gigantimos don't seem that special, this plant had one tomato on one truss only and it's not exceptionally large.
From reading through the replies it seems there is not a single method (as was pointed out) but rather a reaction to weather. So far, my other tomatoes (inside and outside) look healthy, too small to pick yet.
Thank you all for the advice