So I have a bunch of tomato varieties that are new to me this year, getting pretty big in 1 gallon pots. From past experience I know that soon they will be these huge unmanageable plants and will have to go out. I am trying to slow them down by not fertilizing and minimal watering but I give them 2 weeks at most before they are too huge to deal with. It is still getting down to between 45 and 48 degrees at night.They are all supposed to be cold tolerant varieties. But what does that mean? What is the minimum nighttime temperature for a cool tolerant tomato variety?
What are the daytime temps like? That will impact the temp of your soil which makes the biggest difference. Cold tolerant typically means it can survive temps down to just above freezing. Many cold tolerant will be able to set fruit below 50 degrees.
If you are in the high 40’s at night you will be fine. Your plants will slow down growth far more when they are out in the cold than they will with limited water. The underside of the leaves might turn purple, that means that they aren’t getting enough phosphorus because the soil is too cold. Not a permanent problem, as the weather warms it will start growing and becoming greener again.
Thanks mcav0y that was of interest to me too!
Can you tell me are my cold tolerent tomatoes likely to survive light frosts if the days are warm and sunny? Night temps are likely to be 28-40F with day temps likely to be 65-80F.
I have never grown tomatoes before and just want to have an idea of how they will go over the next couple of months.
Our lowest temp so far this year was 42F last night and the tomatoes are currently thriving and setting lots of fruit! The plants are medium and large in size and mostly sheltered from the wind.
Your plants are not going to like you for those cold temps. They will be fine in the day, but at night they will be grouchy and possibly not survive below 35. I guess it depends how much you are willing to pamper them. You could make a mini greenhouse/row cover/hoop house. You definitely have to cover them on those colder nights. I would say go for it, what’s the worst that could happen- your tomatoes die for the winter and you start again in the spring? That’s what the large majority of tomato growers do across the world.
@Ktthevillain: Tomatoes will not survive light frost. If you want them outside during light frosts, you need to cover them with something. That said, you’re in zone 10, and if you feel like going out and putting sheets over your tomatoes when it frosts during the winter, they should make it through to the spring. You’ll probably have to prune them way back in the spring to get strong new growth, but they’ll have a head start over new seedlings.
I’d plant those Maters now. Any tomato will survive anything above freezing. Frosts are freezing temps at ground level, or freezing dew. So covering for frosts are a must.
Not only frosts, but if you get a freeze at ground level, then they’re toast. I cover with sheets for a frost, and use blankets if there’s a freeze. Keep in mind if the thermometer reads 3ºC to 5ºC at 1 meter above the ground, then it’s usually freezing at ground level. I envy your climate. I’d have my portable hoop-house moved over tomato plants and be eating BLT’s all winter long. We have freezing temps for weeks at a time here.
Hot wired if you say so! I’ll work on hardening them off this week.
I’m in zone 5a and I’m planting tomatoes Tuesday. My last frost date is May 9th. I’ve been tilling all day. Last frost date for Seattle is March 22nd, but the “safe” date for planting is April 15th.
Our lows aren’t so low, but our highs are pretty low. Average high for April was 52. I dont think tomatoes would like that.
‘Like’ probably not. But they’ll live with it.
I was going to plant mine out but I’m waiting until payday when I can get the rest of my stakes, because I like to put them in at the same time I plant.
If that was the average temp for the summer (like it seemed to be up here last summer), I would say invest in a greenhouse, but since it will only get warmer for you, plant them out!
I grew my plants in a greenhouse at 40F. The growth is a little slower, but that’s a good thing for building a strong root system. When you have them inside at warm temps, they put their energy into top-growth, so I’d definitely get them hardened and planted. Remember that hardening is 90% about building a tolerance to UV light, and 10% about acclimating to temperature change.
I second @hotwired’s ideas. I also grow my toms in 40-50F until they are ready to start flowering; it creates a strong root system and thick healthy stems. Then they get put in a warmer spot because I want to focus on more development and ripening of fruits. When I said “plant them out,” I really meant “harden them off, THEN put them in the ground.”
Thanks for all the advice guys! I will plan to cover them on the coldest winter nights. I also have a few plants growing in pots on the verandah which will hopefully be warm enough without needing to be covered!!
Our ground doesn’t normally freeze thankfully but we do get those light frosts in the early morning hours and i would prefer not to have to start again in spring (since i got my seeds planted so late).
Winter BLTs here i come!
According to west coast seeds, early varieties can be set out when night time temperatures are reliably above 7°C (45°F).
We are there now!
That’s great news hotwired and anelson! I’m raring to get my toms out into the real world. I’ll start hardening them off today, which will give my peppers some breathing room.