Can't hurt. But where are you? Are your tomatoes maturing when it's getting hot? Once it's very hot, hand pollination isn't going to help. In our area, the trick is to plant as early as possible, so the plants mature before the heat sets in.

I am in SW Pa, zone 6a. Please explain why hand pollination does not work when its hot. and how hot prohibits hand pollination.

You could always choose more productive OP varieties. For example, I LOVE Cherokee Purple, but I found that Margaret Curtain is much more productive (even though the taste of CP is very slightly better).

I will never grow Brandywine again because it never does well for me. It is so late that the fruit rot before they ripen. However, I adore the taste, so I grow Little Lucky instead. The smaller fruit ripen sooner and I seem to get lots. I also love the taste. BW is a parent :).

I don't know about pollination in hot climates, but I have used an electric toothpaste to pollinate my compact tomatoes that I grow in the winter. I also have a friend who lives in Florida and grows 100 or more tomato plants in the winter, and she pollinates them to get more fruit :).

Linda

There is a condition known as 'Blossom Drop' (Google and FAQs here quite informative) that explains the tomato plants inability to pollinate during periods of high heat and/or humidity. Basically the pollen becomes tacky/sticky and non-viable and the bloom dies and "drops". Think of damp talcum powder. ;-)

During such periods one can hand pollinate forever but results will be minimal and fruit is often deformed if it sets. It is a problem we all have to deal with at some point in the season.

Are some varieties more or less affected? Possibly but all varieties are affected to some degree.

https://www.gardenweb.com/discussions/2766768/why-are-the-blooms-on-my-tomato-plant-dying-and-falling-off

Dave

I hand-pollinated with a tuning fork last year. I have yet to do a scientific side-by-side comparison (actually, I have 2 yellow brandywines growing next to one another this year, so I think I'll do that! As one of the varieties toward the low-yielding end, that would be an excellent candidate.) but I had a TON of fruit set last year and very few deformed fruits. So my initial impression is that it can help a lot.

But it's also a myth that heirlooms/OPs are low-yielding because they're not hybrids. I've grown many types that are really productive. Most new heirloom growers seem to go straight to the large-fruited, late-season "prestige" varieties like Brandywines, which are, indeed, lower yielding as heirlooms go. Or they often go for varieties that might not be suitable for their growing area. But there's whole world of open-pollinated tomatoes out there.

As Dave says, when it is hot, the pollen gets sticky/tacky. Vibration of the flowers with an electric toothbrush won't make pollen fall any more than vibration of a toothpaste tube will make toothpaste drop out of the tube. Electric toothbrushes are nice. If you don't have a lot of flowers to help pollinate, just flick the flowers with your finger. Pollination will be reduced if there is little wind and foliage shaking.

It's not quite clear what sort of weather you get, but zone 6a sounds pretty much great for growing tomatoes. As long as you grow outside or at least have some ventilation etc, pollination should not be a problem. It sounds more like a nutrition problem. So called 'balanced' plants set fruit easily as long as weather is not extreme (so with the right amount of everything but not too much)

Cherokee Purple was mid-season for me and productive.

I haven't grown ARGG, but I've grown other green-when-ripe large tomatoes, i.e., Green Giant and Malakhitovaya Shkatulka, and both were pretty early (MS was very early) and very productive for me. MS was almost as productive as Big Beef. GG gave fewer fruit than MS, but the fruit were larger.

WAY more than 6 tomatoes per plant for all of the above. And all were delicious. I had to give many away because I had way more than I could eat before they went bad.

Don't forget that tomatoes have perfect flowers (every flower has both pollen and the ability to turn into fruit). A tomato flower can pollinate itself (although not all plants with perfect flowers can do that). Wind can be enough to cause a tomato flower to pollinate itself by shaking it. So, regardless of whether you have pollinators, if you get a breeze now and then, I wouldn't worry too much. I hardly ever see pollinators on our tomatoes (but there are plenty on other kinds of plants).

Great to know. I don't suppose microscopic spider mites could pollinate, could they? They've probably been crawling around everything in our garden.

Now that our last fruit tree is gone, I wonder if they'll be as abundant this year.

Cherokee Purple was the best tasting tomato I ever grew but the worst yielding variety in my garden (WI). I tried it for several years and sadly gave it up. I presume it does better in a warmer climate and longer growing season than what I have. The last year I grew it some of the plants only produced a few fruits. I guess I had the room I would plant it again but not if I was looking for a lot of production.

Cherokee Purple is one that is prolific and can even be early for some people, but not either for others—from what I've read about it. My guess is it probably does better in certain kinds of soil or something. On average, it seems like people out east rave about it more, but people in dry climates do, too.

Cherokee Purple seems to dislike extended cool weather. People who live far north or in the PNW seem to be less impressed by it.

Much of Washington State is a desert, that's where I live. It is hot and very dry here. Cherokee Purple does excellent for me. Tons of tomatoes, and pretty early.

Hot and dry here as well (Southern California), Cherokee Purple does horribly for me. Horrible to the point where if I get one small ripe tomato out of 5 plants I'm lucky.

I've tried quite a few heirlooms and only keep the ones that taste good and produce well. I was curious this morning, went out and counted tomatoes. My best Black Krim (since the OP mentioned it) has 48 tomatoes on it right now, minus 3 we've already eaten. My best Black from Tula, I stopped counting at 50. Most others are averaging between 30-50+ tomatoes, except my Kellogg's Breakfast, which have about 15-20 each (I consider that pretty good for that variety). They've mostly been in ground since February, just so it can be put into perspective - didn't start them last month and they're already sitting at those numbers ;)

So, anyway, heirlooms definitely can produce more than 5-6 tomatoes. I do "toothbrush" them, and it does help with production, here. Don't fall for the "heirlooms don't produce" hype. You just have to find the ones that produce in your conditions.

Cherokee Purple was a notoriously low producer for me in southern Louisiana. I now grow Indian Stripe and Cherokee Carbon instead. Much better results with that same wonderful flavor.

Orange County, Ca. zone 10, one Brandywine in the ground produced 42 pounds of tomatoes. Probably a combination of ideal tomato weather and growing it on the former site of a compost bin. There are loads of pollinators in my garden because I also have flowering plants, although it's the vibration of the bee's wings that moves the pollen, not the bee itself. Don't wish for spider mites! They can kill your plant.

When high temps cause sticky pollen,will spray bloom set work? Cherry types set fruit at higher temps than slicing types. Will breaking a limb with viable blossoms from a cherry and tapping it on slicing blossoms pollenate them? Will fruit from cross pollination show characteristics of cherry?

I've always bought a varity of hybrid transplants offered at nurseries,yall have inspired me to try growing some heirlooms from seed next year. Mom used to plant out early then cover plants at night when frost was expected. When I try that,the plants usually overheat,go into shock then spend a week in recovery. I rarly read about covering here but hear lots about growing indoors until danger of frost is passed. Are they growing under lights or on a window sill? How much effort is required to harden plants before planting out? I havn't researched stats but this year might be a record short time between cold nights and first 100F day in N.Cent. Tx.

Pollen won't fall out easily from tomato blossoms because they have tubular anthers that require strong vibration to release the pollen outside of the flower. Also, in most varieties, the stigma is inside the anther cone, not sticking out of the flower, so shaking pollen over it won't do anything. When people say that wind helps tomato pollination, it's not because the pollen is carried on the wind but because the wind shakes the blossoms, causing a little pollen to be released from the anther tubes so the flower can fertilize itself.

And while things like vibration may help in humid conditions, extreme heat during the formation of the anthers results in pollen not forming properly, and nothing can overcome that. Different varieties have different tolerance to heat.

klem, there's an FAQ about starting tomatoes from seed here: https://faq.gardenweb.com/discussions/2766771/how-do-i-start-tomatoes-from-seed

Thanks gorbelly,hopfully someone will chime in with how hybrids are created and if home gardeners are able to do it. As far as pollination being halted by heat,I wonder if effect on determinate and in-determinate are different.

Klem, you can certainly breed your own crosses at home. https://www.youtube.com/watch?v=3aj5TPzhDuI