Tomtil's need insect visiting activity moreso than almost any of the garden nightshades (along with "ground cherries"). If you're not seeing bee/insect/etc activity on those flowers, they're probably not going to set well.

It's not uncommon to see Tomtil's flower like crazy for weeks and only "take" when the insects finally discover and pollinate them.

There's also temperature/humidity considerations, but Sept/Oct in north FL, that shouldn't be a pressing issue.

This discussion has come up time and time again, that tomatillo has to have girlfriend or boyfriend to fruit, needs to have visiting insect ... But none is true and I have proven that to be not true(to myself) more than once but twice.

Just this season I planted one Tomatillo plant. It kept growing and blooming but no flowers. There had been enough bees (various kinds) but no results. Come September, it suddenly got loaded with husks. It is actually live and well right now. I will take a picture tomorrow. But the husk will not have a chance to get filled because of cool/cold anyway.

I have com to conclusion that Tomatillo is day length sensitive. Or at least the strain that I have(mexican strain) is. Our summer days here at the PNW being over 16 hours was not just right. So when by September the day length got close to 12 hours flowers started setting fruits. Now all my tomatoes are dead and gone but the tomatillo is the happiest of everything in the garden. At first I was suspecting our not so hot weather but that was not the case.

And one more Thing: we did not have any high temperature, high humidity,The amount sun has been the same ... it kept blooming non-stop from early on. there was no lack of insect problem/. The flowers did not drop. They lasted for days but just did not set fruit. Now maybe it has 200 husks.

Thanks so much guys! I am going to try repoting them today. We experimented with container size, some are in 3 gallon pots & some in 5 gallon. I did put 3 plants in the 5 gallons so I will move them to a 10 gallon and see what happens.
We have a lot of bees in the garden but honestly I think they love the Tahitian Squash & weren't paying much attention to the tomatillos... I will move them closer to the bee habitat, reorienting them in the process.
It's also possible that now we will have a couple months of non scorching temps they will take off like we want them to?
Your guidance is much appreciated! I will keep you posted!

OK. As I said, my tomatillo plant kept flowering all summer long not did not set any husks/fruits. As of early September, when the day length approached 12 hours it suddenly burst into husks.
So, the belief that you have to have more than one plant is not true. I have challenged that once more in the past and have proven that to be wrong. At least to myself.

Here is a close up picture

You don't have to have more than 1 plant...your chance of pollination goes up greatly with more than 1 plant, though.

They are entirely fruitful on their own, especially with visiting insects, but more plants give more open flowers and more of a chance for pollination by visitors.

There's a bit of a misconception about tomtils that they're self-incompatible for pollination...but closer to the truth is that your chances of fruits taking goes up considerably with multiple plants.

nc-crn,
Are ground cherries also finicky this way? I'd like to grow some in a high tunnel next year. They grow fine outdoors but I'd like to get some earlier yields by putting them in a tunnel. I suppose I can't do that if they are dependent on bees.

Ground cherries are considered notoriously picky fruit setters, too.

They do have a good reputation for being acclimated to cooler climates, though. It's not like they're cold climate plants, but they seem to set fruit well in cooler temperatures compared to a lot of Solanaceae.

This post was edited by nc-crn on Tue, Oct 15, 13 at 20:24

Yeah they were just fabulous this year. I had them planted next to a hay field, and the patch was buzzing with bumble bees all summer long. But I got a relatively narrow harvest season from mid August to late September.

Seysonn, your tomatillos look much happier than ours!! Of course it's been raining for days so I haven't had a chance to repot mine... Are yours in the ground? Anyone having luck in containers?

MidnightG .... yes mine is in the ground . It is huge. Too bad, it started too late. . BUT i will let'm live till frost.

Tomatillos are pollinated by bees and other insects that move from flower to flower. When temperatures or humidity are extremely high, the pollen adheres to the inside of the flower, making pollination difficult. ... Tomatillo plants aren't good self-pollinators.