I had a big problem with blossom drop on my tomatoes this year. I'm pretty hard on my plants so there are all kinds of things that could have contributed to it, but I'm wondering if it was the heat we had this year since other people in my area (with different watering habits and soil) experienced the same problem. Does anyone here grow tomatoes that perform well when temperatures are in mid to upper 30s C for more than a few days at a time? If lots of people have no problem with this, then it's probably not the heat but one of the other tortures I subjected them to. If most people have problems when it gets hot, are there tomato varieties you've noticed that perform better at high temperatures?
Do best with night temps above 50F and days of less than 85F, especially older heirloom varieties and most beefsteaks. (there's one called Mr. Stripey, if it gets low 80'sF it does well, otherwise pull it out. If it gets things like it wants, it's delicious).
Afternoon shade, between 2 and 5 pm and even a little earlier to later. This isn't full shade but such as you would get from a tree or 30% shadecloth.
Windbreak. There is such a thing as windscald.
More than single digit humidity.
Less altitude not more, though that can be helped with shade.
Have your soil tested, if you are short on calcium you will get blossom end rot and that also causes problems.
I am in zone 6b at 4200ft and microclime is pretty close to high desert. This is the original dustbowl and it gets dry, lots of wind, and issues to be fought with subsurface moisture.
Heat loving tomatoes:
Heatmaster, Solar Fire, Summerset, Phoenix,
Florida 91 (commercially available plants, I can say Florida 91 did lousy for me here)
Big Beef (sort of another 'meh' but better than some)
Fourth of July (small strip cluster) (okay)
Heat wave II
Homestead 24 (not the greatest)
Manaluche, Mountain Crest,
Porter (okay but small fruit)
Sanibel, Solar Fire, Spitfire, Sunbeam, Sun Chaser, Sun Leaper, Sunmaster,
Super Fantastic (this is an improved and more disease resistant than Fantastic) (did pretty well here and medium fruits)
Brandywine (I usually grow Suddeth or pink, NOT potato leaf. Have to work at getting starts early and BIG and happy then in ground, and with enough regular water, settle in and produce. One of my regulars)
Early Girl (susceptible to blossom end rot, but does produce medium small and lots once it gets going)
Roma VF (likes to sunscald, I usually run 2-3 rings of support caging, determinant but will produce well)
I have also had good luck with Yellow Perfection. One of my earliest and the scraggliest sickliest looking vines but they will produce a few every day until frost once they get going. Is a go-to for fresh breakfast omlette additions here..
Black Pearl. These things have an itch factor, are like hunting easter eggs, and once they get going take over. They will also produce in direct sun here. 1-2oz fruits with a shoulder blush. Set them with a beefsteak rated tomato cage and steel fencepost.
Joseph Lofthouse Short Season (I lost the Red Stump and Hamonsita seedlings this year) they are squatting and making fruits right now, and very pleased with them.
Joseph Lofthouse is producing Landrace, which means he is picking the survivors at his warmer climate but higher altitude semi-desert location. I have slightly better conditions and his stuff grows here well. He also selects for flavor, so all his strains tend to be delicious.
By windbreakng to my worst sustained summer winds (SSW at 25mph) and afternoon shade from tree or growing under 30% shade cloth, have had very good results. I do have to put gypsum in for calcium issues and will use blossom end rot spray as a preventive for those issues.
There are many other varieties I have tried and will continue to try stuff to find a better tomato.
Early blossom drop in heat, give windbreak and shade, do make sure air can circulate though, and that will help some. Heat can cause many things to drop blossoms, and across the board, windbreak and shade... Adding soaker hose or T-tape or drip emitters and MULCH will help also. Or so it does here. (I see heat related drop in tomatoes, peppers, strawberries, pumpkins and related cucurbitaceae..)
I'm a pretty hands-off gardener, and I'm not going to be messing with shade cloth or watering any more than is convenient for me (no running water) so I need good varieties to grow for my conditions. I'll check out some of your suggestions.
Do you have experience growing any purple/black varieties other than the Black Pearl in high heat? I see cherokee Purple and Black Krim appear on some heat-tolerant tomato lists and I already have seeds for those, but didn't grow any this year. Any input on those or others? I grew Black Beauty which did okay, but it dropped blossoms for a while too, and Roger's best black which was not happy at all.
I've tried Cherokee Purple and Cherokee Carbon this year. Cherokee Carbon has just been slow off the block, though it is in the RGGS system pails and has 30% shadecloth. It's still debating on setting fruit. The Purple just didn't thrive.
I finally got a Black Sea Man from Tula, been trying for that for years. The cut fruit looked interesting. I can say it's a really meaty beefsteak type, and prone to cracking and doing fused megabloom fugly/fused tomatoes.
If you can recruit a tree to give you that afternoon shade that is a lot lower work. The year I was growing competition tomatoes along with competition pumpkins, I put the tomatoes in local high noon to an hour before sunset shade from a tree and turned it into a bit of a swamp (watered to give air cooling as well when temps hit 85F (to be fair that was the year we had a week of 113-117F) and turned off two hours before dark to let it dry out to prevent powdery mildew. I did get a red brandywine to give me 20 fruits over 1 pound, another 16 over 12 oz, and one at 1.52 pounds. It was in the boggiest part near the impact sprinkler head mounted on a steel post and got the most cooling and water. Fruits were so big I had to get old pantyhose and rig little hammocks so they didn't pull off the plant. (it gave me about fifty fruits, none less than 7 oz)
I got a few Black Krim, first year I've tried them, and nothing really outstanding in either size or production.
I truly recommend Joseph Lofthouse's landrace seeds if you want something that will produce and take some abuse and neglect. Note the word SOME.
Another bit about tomatoes, do put some time in on them when they're small and you'll love yourself later and so will the plants.
I plant in and put marigolds, either French or the special nematode chasing varieties (Golden Guardian or Nemagone) with the tomatoes. This is one companion planting that pays seriouis dividends. Two to four plants about 6" away from the tomato plant. (I plant inside the circle of the cages) This makes a big difference in the growth and production of the plants. Don't grow tomatoes without their marigolds! If you start tomato plants from seed, start the marigolds at the same time so they can go in the ground at the same time. Even in my RGGS (self watering pail system, or Rain Gutter Grow System) I will put 1-2 marigolds in each pail.
As the tomato plants grow and the training to stay in the cages start, I start removing bottom leaves and taking suckers. So that by the time a plant is 18" tall, it is clear to 6" from the soil to the first leaves. A 3-4 foot plant will be bare 12-18". I stop at about 18" on say a 5' tall or taller plant. This helps prevent a lot of disease issues, lets air circulate at the bottom of the plant, and otherwise makes later care of that plant easy. It helps to see the weeds easier to remove the competition.
I strongly suggest for anyone growing tomatoes, buy a copy of this book: https://www.amazon.com/Giant-Tomatoes-Marvin-H-Meisner/dp/0975515314/ref=tmm_pap_swatch_0?_encoding=UTF8&qid=1505950218&sr=8-1 How to grow Giant Tomatoes. As he said, he retired and wanted to grow tomatoes, especially competition ones, and nothing out there was very organized, so he found out all he could, grew some, and wrote the book. It is for growing competition fruit, but. FIRST he tells you how to grow tomatoes. THEN he tells you, if you want to grow for greatness, how to do that. If you stop before the last part, you will have nice healthy tomato plants that will produce.
I can vouch that I use a lot of what is in that book, though I use things like DE, compost tea, etc; and the companion planting marigolds. And I have grown for greatness. I've also started suckers and airlayer propagated tomato plants. Maybe your library has a copy or will get one for you. Good luck.
One more note, if it seems you are always hitting the hottest part of your growing season just as your plants are trying to set, it might solve problems to shift growing season by starting plants earlier or later to start setting before the hottest part of your season. I do two cold season, one hot season, and one long season that overlaps the others, here. It is a fight to get cauliflower and broccoli here as it has to come into maturity just before it heats up, then making sure the seedlings for fall are started early enough to finish out before coldframes won't work any more. Coldframes can be made from a ring of bales, an old window pane that will cover completely, and a couple of old blankets for cold nights/and or snowy days.