Return to the Growing Tomatoes Forum | Post a Follow-Up

Effect of cold weather on planted tomatoes

Posted by maryann45 z8bGA (My Page) on
Tue, Mar 29, 11 at 9:31

I am in Savannah, GA. I planted my tomatoes on March 26 - 2 weeks after the last frost date. Since then we have not had frost, but cool, rainy, cloudy weather - almost no sun so the plants have been wet a lot. The temp dropped to 44 last night and is expected to be in the 40s most nights thru the weekend (today is Wednesday). I have covered them at night, but of course that doesn't help much with the temps and just keeps them damp. Does anyone know if and how this will affect my tomatoes? Should I cover them at night or leave them open so they can dry out?

Follow-Up Postings:

RE: Effect of cold weather on planted tomatoes

Temps in the 40's are not going to harm your tomatoes. They won't get much growth until temperatures are higher, but I would quit covering them and let them dry out.

The only time I would cover tomatoes is if a freeze is forecast. Hope that helps and good luck.

RE: Effect of cold weather on planted tomatoes

Agree. 40s won't hurt them but keeping them covered can. Cover only if the air temps at ground level are in the lower 30s. Set a thermometer at plant level since forecast air temps are at the 5-6' level.


RE: Effect of cold weather on planted tomatoes

Will do as you 2 suggest. Thanks a bunch!

RE: Effect of cold weather on planted tomatoes

I disagree with what has been posted based on scientific findings concerning temperatures and damage.

No they wont "freeze" but plants have shown to get damaged at temperatures below 45. Much depends on the variety, how hardened they are when the exposure started, the amount of wind and the length of exposure but it would be best to keep them covered for now.

At temps below 55F most plants just sit there.

RE: Effect of cold weather on planted tomatoes

I dont have access to scientific data but have planted tomatoes in the past when night lows had dropped to low 40s and hi 30s. And my plants did fine that season.
More than air teperatures, soil temperatures are important.
When soil temperature measure over 60, during the day, it is not going to cool down considerably (at roots level at night) even when air temperature goes down to 30s.This is especially true, if the plant is mulched well.
But as mentioned above, surviving is one thing and growing another. That is why , in my experience, late planted tomatoes catch up with the early one, very fast in warmer soil and air temperature.

RE: Effect of cold weather on planted tomatoes

I am a total newb, but I have to agree with mulio. I started a few seeds in a cold frame in the middle of December (average low 40). The seedlings started great but showed obvious cold stress later. I then started the same seed indoors with artificial light and brought the outdoor seedlings indoors to place under this same light. The cold stressed plants never recovered and my new seedlings outgrew the competition.
I would suggest not placing them outdoors until the temps are averaging 55, or 50 but with some form of cover. Good luck.

RE: Effect of cold weather on planted tomatoes

We just had a 7 day stretch of weather like metioned in the opening post. My plants got hammered and took some damage and didn't look great. Since then the weather here has warmed up (80 expected the next 2 days) and my plants are bouncing back very nicely.


RE: Effect of cold weather on planted tomatoes

I think the problem is a lot of people set out tomatoes that are not properly hardened off. A tomato plant that is ready for the outdoors should have no problems at 40 degree temps. In my opinion high winds are much more of a problem than cool temps.

I have no scientific evidence to back up my statements, all I have is 50 years of gardening experience.

Eetrey, 40 is too cold for small seedlings. Gotta make them tough first.

 o Post a Follow-Up

Please Note: Only registered members are able to post messages to this forum.

    If you are a member, please log in.

    If you aren't yet a member, join now!

Return to the Growing Tomatoes Forum

Information about Posting

  • You must be logged in to post a message. Once you are logged in, a posting window will appear at the bottom of the messages. If you are not a member, please register for an account.
  • Please review our Rules of Play before posting.
  • Posting is a two-step process. Once you have composed your message, you will be taken to the preview page. You will then have a chance to review your post, make changes and upload photos.
  • After posting your message, you may need to refresh the forum page in order to see it.
  • Before posting copyrighted material, please read about Copyright and Fair Use.
  • We have a strict no-advertising policy!
  • If you would like to practice posting or uploading photos, please visit our Test forum.
  • If you need assistance, please Contact Us and we will be happy to help.

Learn more about in-text links on this page here