When to harden out/ plant out tomatoes

[CubanBenny]

I am wondering when people think is the perfect time to plant out tomatoes. I grow all my tomatoes outside here in Dublin. They are semi hardy heritage varieties that yield well every year for me.

However, I never know when to plant out

Coldest nights currently forecast are for 6 days time, where it's forecast to drop to 6 or maybe 5 degrees.

Previously, when my tomatoes have been exposed to these temperatures, the leaves have turned purple and the plants have been stunted. I think it's supposed to be from Potassium deficiency. So, I have tried spraying them with a Potassium rich fertilizer to overcome this.

I have just started hardening them out by bringing outside for a couple of hours a day.

Wondering what other people think/ are doing?

[burnie]

With the weather we have forecast, I am worried about tomatoes inside my greenhouse, I certainly would not want to have tomatoes outside just yet.

[ameno]

Mine are currently outside on the patio hardening off full time, as we're having warm nights for a few days. Like you, colder nights are forecast in a few days time (Sunday night to Tuesday night, inclusive), so I will bring them back in for those night. Then if the forecast looks good after that, I will probably plant them out Wednesday or Thursday next week (13th/14th).

[annie8]

It’s getting really awkward to keep bringing them inside but too cold here overnight and the next few nights are going to go down to about 4 degrees. Might be able to put them overnight a few nights before putting them out completely but there haven’t been any nights yet where the gh temp as been as high as 10.

[Bren In Pots]

In my area we're due to have temps of 1c during the early hours of Wednesday morning so my Toms are staying indoors on the window sills.

[littlemoney]

Thanks for the warning I have just brought my tomatoes and french beans in from the cold frame. Never done that before after starting to hardening off

[Bumblingbroccoli]

I may be crazy but I have 9 planted out since the weekend. They are planted through black weed suppresser and I have covered with fleece. Prob a bit cold but temps not below 3 degrees and mostly above 5 at night. And if they cark it I have another 12 in the greenhouse ready to harden off!

[Penellype]

If you can possibly wait a while longer it would be best to do so. While the weather may warm up over the next few days, we are due a likely arctic blast at the weekend, which could result in both frost and snow in places. It is forecast to be unusually cold for the time of year, and by Sunday temperatures could be struggling to reach double figures during the day even in the south - Sunday/Monday here are currently forecast to be max 8 and min 0 (usually upto a couple of degrees out either way). There is still time for it not to be quite as bad as the models are predicting, but all are now in agreement that it will be cold.

The forecast 2m temperatures are uncomfortably close to zero (for York at least) for the following week, possibly beyond:

[annie8]

Put the tomatoes out into the greenhouse. Have planted most in their final pots -bucket size - so no way they are coming in again. Put a bit of fleece over them but temp seems ok.

[peanut]

Mine will be spending their first night in the greenhouse tonight. Hoorah for double figure night time temps!

[Penellype]

Looking better from a temperature point of view (no frost in the forecast) but unless you are in a very warm area it is still a bit chilly at night to plant tomatoes outside. They should be fine in an unheated greenhouse unless you are in a cold area or in the north.

[Bren In Pots]

I left mine in the GH last night the temp was 10.5c plan for today is the plant them in the GH border.

[ameno]

Mine were planted out at the allotment today. Six plants. Some of them were already 2ft tall. Definitely sowed too early...
They've been out on the patio hardening off since early May, although I had to bring them in for 5 days during that cold snap last week, so that delayed things a little.

[bramble]

Mine are in my unheated greenhouse for the last two weeks.
They will stay there now as they are in their final containers.

[annie8]

Planted tomatoes in the raised beds yesterday