Can Heat Affect Plant Growth?

[Fred in Maine]

This heat has certainly reduced fruit set in my garden. What really baffles me is how much smaller my plants are this year. Most are about half the size of last year.

Is it possible that this sledge hammer heat has stunted the plants' growth?

[TomatoDon]

Yes, it can make a big difference. Not only in plant size, but how many blossoms the plant makes, it they fall of due to heat or actually produce fruit, and size of fruit. Most here at T'ville seem to have had a unusually hot summer.

[b54red]

I do staggered plantings from early spring through August. I have found that the first two plantings almost always have the larger plants with larger fruit. The seedlings that I set out towards summer grow slower and try to set fruit sooner but they rarely reach the size of the ones set out in early spring.

[mensplace]

I feel sure that had I not planted my tomatoes very early, between the extreme, sustained heat, humidity, drought, and infestation of insects in the garden now, I would not have enjoyed the fruits I did. The temps have been in the upper 90's every day for many weeks and the outlook is for them to rise even higher throughout this week. Even without bearing fruit, the plants themselves are pitiful looking, with the only sign of green being at the tops. With August and September being our hottest months, I can't even foresee more productivity from them this year. Have been tempted to cut them back to a few feet from the ground, but have read here of tomatoes starting to produce again in the fall. Too, in the production of tomatoes in greenhouses, they lower the viney part of the plants and lay those along the ground, while picking from the new growth. I'm debating whether it is better to cut them all down and start with new plants, or rely on patience. Your experience?

[Timmah!]

I've read of folks that allow the plant to root in a second spot & use that as an additional point of feeding, whether via direct watering or a subsoil reservoir.

[nctomatoman]

My big lesson from 2010 will be to get my tomatoes planted as early as possible. Our Raleigh oven effect has pretty much ruined my season - both in terms of plant health, and yield. Worst tomato crop will experience in 25 years, I suspect!

[barkeater]

Craig,

I don't know how you (or your tomatoes) can handle such temperatures! My sister moved to Durham last year, and I can't remember a high lower than the nineties there the last 2 months, and many at a 100.

Now you know why I moved up near the Canadian border!

[creister]

Heat defiantely will slow plant growth, fruit set, and fruit size. I used to be concerned that I never got many fruits that fell into the size range on the package. Early fruits will, but once we start getting some hot days, they start not to grow as large.

If you compare animals in the north and the south, those found in the north are always large on average. Average body weight of Texas deer is less than those of Michigan.

[northraleighboy]

The heat in Raleigh has indeed been ridiculous this summer (Thank you Bermuda High) and my container tomato plants on my deck have borne the brunt of it. I'm getting simultaneous BER and cracking indicating inconsistent watering issues, but the truth is I water every morning and come home and find their soil to be bone-dry. There is nothing I can do about it.

Maybe it will start cooling off in November.

[chalstonsc]

North....depending on the size of your containers, you may be able to support them over a resevoir of water....put nylon wicks up the drain holes and dangle into water...soil will not dry out.