Are those indoor or outdoor?

Regardless where they are it's lack of pollination. Try spanking or shaking the plants, gently of course.

The plants are outside and it has been very breezy this spring.

How hot is it there now?

sirwes,

Patience. Every year about this time people ask why they don't have any tomatoes yet. Most cherries are 60-70 days from the date you transplant them. The early blooms may not have set fruit because of the stress of transplanting. So the blossoms that occurred 3 weeks or later after the transplant are the ones most likey to have set a tomato. If you look real close where some spent blooms are, between the sepals, you may see an itty, bitty, tiny little green tomato. (Or dozens when you spot one, there's usually more on cherry tomatoes.)

BTW, I think two tomato plants is about one too many for a Topsy-Turvey. Actually, two plants may be two too many. LOL!

Betsy

You are right that 2 is too many but they should still set fruit. The quality and quantity will be poor.

Someone asked about the weather. That is part of my impatience. Although it was cool today, we have already had three 90 degree days here in Phoenix. Within six weeks, we will be well over 100 degrees. Part of the reason I bought the upside down planter I thought I might get away with moving the planter to afternoon shade when temps exceed 105. I have no idea if that will work or not.

Toppsy Turvey, I had read the one complaint about these is they tip over easy, so when I planted it, I put 60 pounds of bricks on the base. We had 50mph winds over the weekend, so I think the bricks are going to do the trick.

l also thinks it too early to be concern however if its past the 60-70 days and every thing was done right yes then l would worry. give it some time

we have already had three 90 degree days

Ahhhh...... Didn't know you lived where it is so hot. (It would help if you would modify your profile to include you growing zone (and state.)

Tomato pollen becomes sterile at temperatures around 90-95ð and up, although in my experience cherries tend to handle it better. Here is the link to the FAQ on blossom drop, but bear in mind the remedies they mention are recommended for plants in the ground, not in a bag up in the air.

I am conjecturing here from the experience I have seen others have with that type of planter. How often do you water your planter? Those planters are notorious for drying out too rapidly, and if you just pour water in the top the effect is for the water to run down the inside of the bag without really wetting the growing medium. Think flash floods on dry hardpan soil, tons of water run over it, but if you dig into it right after the flood, it isn't wet past the top inch or so. Blossoms on stressed plants tend to drop.

One of the easiest ways to make sure the growing medium is watered is to deliver the water as slowly as possible. A drip system is ideal. If that's not feasible, you can take a gallon jug, make a tiny pinhole in the bottom and set it in the top of the topsy turvy to leak the water out slowly allowing the growing medium time to absorb the water rather than it cascading down the insides of the growbag.

But you have basil in the top of your planter, so you may have to figure out how to hang a jug to drip into it. Or you can use plant watering spikes with 2 liter bottles Also, in your heat, you are probably going to have to water at least two or three times a day.

I hope that helps.

Betsy

Here is a link that might be useful: Blossom Drop of Tomato

sirwes,

I see that your profile now includes Arizona in it. My apologies for not noticing that you had changed it. It would be a good idea to add your zone since Arizona has zones from 5a though 10 in it.

Betsy

Here is a link that might be useful: GardenWeb's Zone Finder

Arizona was always in the first post. That's why I asked how hot it was. A couple days in the 90's is not a problem for fruit set IME but when you hit 90's to triple digits and stay there for extended periods they will not set fruit.
Have you been using any fertilizer (possibly high in nitrogen)and are they in full sun for over 5 hours a day??

4 basil plants on top? Er...I usually plant one per sq. foot in my raised beds and it takes up the whole thing. My genovese plant was as big as my cherry tomato plants last year. I'd do one, tops. It's already going to be pretty overcrowded root-wise in there with two tomato plants, imo.

The night low temps and humidity also make a difference. I know this from personal bitter experience. Cooler night temps may balance high day temps.

Very good point and that's what I was getting at by "hit 90's to triple digits and stay there for extended periods". It's not just the day temps being in the 90's. It's constant 90's+ that hurt production IME.

Could the roots be getting too hot in the planter? I'm not sure that would affect production. I have similar weather here and topsy turveys do not do well in full sun around here, even with one plant in them. They dry out too fast and the roots get too hot under the plastic. I imagine with 2 plants and some basil, there are lots of roots in there.

topsy turveys, against the wind, running, we were always running against the wind. No chance, buttttttttttttt I wish you luck.
Plant em if you got em.
Sam