Keeping roots cool in extreme heat?

Master Shake · October 8, 2020

Hello tomato peoples,

Does anyone have special tips for growing tomatoes through extreme heat?

I have an idea of putting down some weed matting and covering that with thick mulch to keep the roots reasonably cool and i have mesh bags to protect tomatoes from fruit fly etc.
Which i'm planning to attaching a piece of cloth to one side of each bag to protect fruit from sunscald as well.

The extreme days and warm nights may cause flowers to drop, not much i can do about that though. (Warm nights is a major cause of flower drop i think?)

Thanks for any input.

Barb_FL · October 8, 2020

I'm covering my Earthbox's with the potting mix bags and it is keeping the box itself (roots and 3 gallon reservoir) cool. Doesn't look so pretty, but plants did not have problems adapting the plantout.

I also cut a shower curtain liner and that is working well too. Also using not used Earthboxes to place in front of the ones with plants.

b54red · October 8, 2020

If you are growing in the ground then get a dense mulch like cypress mulch and put at least a 4 inch thick layer out at least two feet from the plant in all directions and further if you have the mulch. Make sure to water more often to stop blossom drop as soil too dry during times of high heat is more of a cause of blossom drop than the heat itself. As a matter of fact it is better during the fruit setting stage during high heat to over water than to give the plants a chance to dry out too much. If you can get any Texas Tomato Food feed them once a week with it. In short to get fruit set keep the ground moist and cool and feed them some.

Other tricks that help is keeping the plants pruned to no more than four or five stems but fewer is better especially with large fruited varieties. Keep the plants free of pests that can suck the life out of the plants in the heat especially mites. Regularly spray with fungicides to keep the leaves as healthy as possible in the intense heat. Make sure to do your spraying very late in the day.

I would only use shade to protect sensitive varieties like Red Barn from sun-scald unless you have poor foliage cover. I almost never use any shade cloth on my tomatoes but sometimes use it on bell peppers which are much more sensitive to scalding in high temps.

Another important thing is to plant varieties that will readily set fruit in high temperatures if properly maintained. No matter how well I follow the steps above there are just some varieties that won't set many or sometimes any fruit if the conditions are really hot and humid. There are varieties that will set well in high temps and even in high humidity. I'll give you a short list of the ones that usually work for me in the midsummer heat.

Indian Stripe Potato Leaf
Spudakee
Hege German Pink
Prudence Purple
Granny Cantrell
Neves Azorean Red
German Johnson
Red Barn
Stump of the World
Limbaugh's Legacy
Giant Belgium
Brandywine Cowlick's

The ones listed are mostly medium to very large beefsteaks that have done well in the last two years but some years one or two of them won't set as well as I hope. I didn't list all the ones that have done great some summers but tried to list the most consistent ones that I could recall. I don't grow cherries anymore but some of them can make a ton during the heat as well as some of the small salad tomatoes.

Bill

Tormato · October 8, 2020

2 1/2 to 3 inches of mulch does it for me. It will compact a bit over the season. Anything less, and you may be courting trouble.

I don't use it on peppers, as it keeps the soil too cool.

Master Shake · October 8, 2020

THANK YOU guys.

If anyone else grows tomatoes in extreme heat PLEASE share your tips that have helped, if you have any.

Nannon · October 10, 2020

The shade cloth over the garden will really help too. Or if you can’t put it up over the garden then around the garden to supply shade. If you have dry heat it should make a huge difference. If you’re in the tropics then the lack of air flow and humidity will likely cause fungal issues.
Are you growing in the ground or in pots? What sort of summer temps do you get where you are?

Whwoz · October 10, 2020

Where Master Shake is can regularly nudge 110F, generally with low humidity in summer, not sure about night temps, it maybe beneficial to the plants to give a short burst with a soaker hose spraying up on those hot nights Master Shake. Not too long as you need to allow the plants to dry without risking fungal problems. How open is your garden or are you in a typical Australian backyard situation hemmed in by paling fences? In our last hot summer, 2 years ago down here after last seasons fire affected one, a number of people I know who grow in suburban type backyards had a lot of issues with heat burn killing plants. I myself, living on a small acreage surrounded by farmland with nearly constant breeze did not have anywhere near the issue, Being able to pump out of a dam of an evening (I would regularly water tomatoes starting around 7pm) for half an hour or so would cool off the patch quite a bit. Sprayed up only when I was sure plants would dry.

Master Shake · October 11, 2020

Quote:

Originally Posted by Whwoz

Where Master Shake is can regularly nudge 110F, generally with low humidity in summer, not sure about night temps, it maybe beneficial to the plants to give a short burst with a soaker hose spraying up on those hot nights Master Shake. Not too long as you need to allow the plants to dry without risking fungal problems. How open is your garden or are you in a typical Australian backyard situation hemmed in by paling fences? In our last hot summer, 2 years ago down here after last seasons fire affected one, a number of people I know who grow in suburban type backyards had a lot of issues with heat burn killing plants. I myself, living on a small acreage surrounded by farmland with nearly constant breeze did not have anywhere near the issue, Being able to pump out of a dam of an evening (I would regularly water tomatoes starting around 7pm) for half an hour or so would cool off the patch quite a bit. Sprayed up only when I was sure plants would dry.

I live in town but have a huge yard, i will be using dripper hose to water them.
Do you think i should use a sprinkler on super hot nights for 10 minutes?

Also, watering at night is recommended isn't it?
I know when we have water restrictions it's between 6pm to 10pm i think, so that's when i would water the last few years, but i don't think we have any restrictions this year.

Whwoz · October 11, 2020

Quote:

Originally Posted by Master Shake

I live in town but have a huge yard, i will be using dripper hose to water them.
Do you think i should use a sprinkler on super hot nights for 10 minutes?

Also, watering at night is recommended isn't it?
I know when we have water restrictions it's between 6pm to 10pm i think, so that's when i would water the last few years, but i don't think we have any restrictions this year.

Try it if you want to Master Shake, but watch out for signs of fungal problems on leaves, although from what I see of your weather you should not have to many problems getting the plants to dry off of an evening.

zipcode · October 13, 2020

Quote:

Originally Posted by Master Shake

I live in town but have a huge yard, i will be using dripper hose to water them.
Do you think i should use a sprinkler on super hot nights for 10 minutes?

Keeping well watered at night in the summer is the way to go if you want to keep the plants reasonably vegetative. Not sure it's just about cool, but also water absorption lowers when the soil is warm so they need good water saturation.
I use alu foil on my pots, but I guess that's another story, for soil probably a thick white mulching foil would be best, usually they have them for sale in countries with heat problems, but also I saw them used to cover asparagus in spring (the white asparagus).

Volvo · October 14, 2020

Try mulching around your plant and water well in the morning , keep an eye on how wett he soil is around your plant every few days.
The Mulch/Hay will keep the heat off them and should keep the roots cool. What i do for other plants come our Summers here ..

Redbaron · October 24, 2020

I use mulch in the rows, living grass between rows, companion plants like basil between every two tomato plants, and a periodic giant sunflower every 10-30 feet or so for shade. I have been able to manage fruit set and minimal watering in Oklahoma summers where temps reach 100+ f (38 c) frequently. Although at the highest summer heat, fruit set slows way down. Looks a bit messy sometimes, but there are tomatoes!

slugworth · October 24, 2020

I let the grass grow taller for more shade/cooler soil.
I just dug up a plant that was still alive at this late date, for indoor fun.
It has blossoms and green tomatoes.
The tall grass protected it from a direct hurricane hit.

October 8, 2020	#1
Master Shake Tomatovillian™ Join Date: Oct 2019 Location: australia Posts: 117	Keeping roots cool in extreme heat? Hello tomato peoples, Does anyone have special tips for growing tomatoes through extreme heat? I have an idea of putting down some weed matting and covering that with thick mulch to keep the roots reasonably cool and i have mesh bags to protect tomatoes from fruit fly etc. Which i'm planning to attaching a piece of cloth to one side of each bag to protect fruit from sunscald as well. The extreme days and warm nights may cause flowers to drop, not much i can do about that though. (Warm nights is a major cause of flower drop i think?) Thanks for any input.

October 14, 2020	#11
Volvo Tomatovillian™ Join Date: Mar 2006 Location: Australia Posts: 289	Try mulching around your plant and water well in the morning , keep an eye on how wett he soil is around your plant every few days. The Mulch/Hay will keep the heat off them and should keep the roots cool. What i do for other plants come our Summers here .. __________________ Good Better Best Never let It rest Until Your Good Is Better And Your Better Best

October 8, 2020	#2
Barb_FL Tomatovillian™ Join Date: Apr 2014 Location: Indialantic, Florida Posts: 2,000	I'm covering my Earthbox's with the potting mix bags and it is keeping the box itself (roots and 3 gallon reservoir) cool. Doesn't look so pretty, but plants did not have problems adapting the plantout. I also cut a shower curtain liner and that is working well too. Also using not used Earthboxes to place in front of the ones with plants.

October 8, 2020	#3
b54red Tomatovillian™ Join Date: Sep 2009 Location: Alabama Posts: 7,068	If you are growing in the ground then get a dense mulch like cypress mulch and put at least a 4 inch thick layer out at least two feet from the plant in all directions and further if you have the mulch. Make sure to water more often to stop blossom drop as soil too dry during times of high heat is more of a cause of blossom drop than the heat itself. As a matter of fact it is better during the fruit setting stage during high heat to over water than to give the plants a chance to dry out too much. If you can get any Texas Tomato Food feed them once a week with it. In short to get fruit set keep the ground moist and cool and feed them some. Other tricks that help is keeping the plants pruned to no more than four or five stems but fewer is better especially with large fruited varieties. Keep the plants free of pests that can suck the life out of the plants in the heat especially mites. Regularly spray with fungicides to keep the leaves as healthy as possible in the intense heat. Make sure to do your spraying very late in the day. I would only use shade to protect sensitive varieties like Red Barn from sun-scald unless you have poor foliage cover. I almost never use any shade cloth on my tomatoes but sometimes use it on bell peppers which are much more sensitive to scalding in high temps. Another important thing is to plant varieties that will readily set fruit in high temperatures if properly maintained. No matter how well I follow the steps above there are just some varieties that won't set many or sometimes any fruit if the conditions are really hot and humid. There are varieties that will set well in high temps and even in high humidity. I'll give you a short list of the ones that usually work for me in the midsummer heat. Indian Stripe Potato Leaf Spudakee Hege German Pink Prudence Purple Granny Cantrell Neves Azorean Red German Johnson Red Barn Stump of the World Limbaugh's Legacy Giant Belgium Brandywine Cowlick's The ones listed are mostly medium to very large beefsteaks that have done well in the last two years but some years one or two of them won't set as well as I hope. I didn't list all the ones that have done great some summers but tried to list the most consistent ones that I could recall. I don't grow cherries anymore but some of them can make a ton during the heat as well as some of the small salad tomatoes. Bill

October 8, 2020	#4
Tormato Tomatovillian™ Join Date: Feb 2006 Location: MA Posts: 4,959	2 1/2 to 3 inches of mulch does it for me. It will compact a bit over the season. Anything less, and you may be courting trouble. I don't use it on peppers, as it keeps the soil too cool.

October 10, 2020	#6
Nannon Tomatovillian™ Join Date: Aug 2015 Location: NSW Australia Posts: 11	The shade cloth over the garden will really help too. Or if you can’t put it up over the garden then around the garden to supply shade. If you have dry heat it should make a huge difference. If you’re in the tropics then the lack of air flow and humidity will likely cause fungal issues. Are you growing in the ground or in pots? What sort of summer temps do you get where you are?

October 10, 2020	#7
Whwoz Tomatovillian™ Join Date: Jun 2013 Location: Victoria, Australia Posts: 870	Where Master Shake is can regularly nudge 110F, generally with low humidity in summer, not sure about night temps, it maybe beneficial to the plants to give a short burst with a soaker hose spraying up on those hot nights Master Shake. Not too long as you need to allow the plants to dry without risking fungal problems. How open is your garden or are you in a typical Australian backyard situation hemmed in by paling fences? In our last hot summer, 2 years ago down here after last seasons fire affected one, a number of people I know who grow in suburban type backyards had a lot of issues with heat burn killing plants. I myself, living on a small acreage surrounded by farmland with nearly constant breeze did not have anywhere near the issue, Being able to pump out of a dam of an evening (I would regularly water tomatoes starting around 7pm) for half an hour or so would cool off the patch quite a bit. Sprayed up only when I was sure plants would dry.

October 24, 2020	#13
slugworth Tomatovillian™ Join Date: Oct 2014 Location: connecticut,usa Posts: 1,150	I let the grass grow taller for more shade/cooler soil. I just dug up a plant that was still alive at this late date, for indoor fun. It has blossoms and green tomatoes. The tall grass protected it from a direct hurricane hit.