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.

Probably fruitworms. They are moth larvae. The moth, usually active at night, lays tiny eggs. The eggs are hard to see unless you catch them at just the right time, in just the right place. When the eggs hatch the very small larvae find the fruit and burrow in. That's where the larvae stay and grow, along with the fruit. Once big enough, they sometimes travel fruit to fruit leaving a mess behind them. I have never noticed the eggs and never noticed the larvae on leaves. I'm not sure I want to notice them. But they are hard not to see once they invade the fruit. :-) I hate these things - they give me the creeps. I found that spraying the plants with an insecticide for vegetables (such as Safer for vegetable gardens) every week or two has prevented this from happening. I don't get too fancy - just spray the leaves, especially near the flowers and young fruit. I don't go crazy with getting undersides of leaves - I hit them when I can but don't bother with the ones that are too difficult to get at. I start at the flowering stage and then spray every week or two (usually every 2 weeks because I'm forgetful). That does a good job of keeping the fruitworms at bay. I've rarely seen a fruitworm in the last couple of years as a result. I realize that doesn't help you now because the damage is already done, but it may help in the future. I just grow about 10 tomato plants and find that the quart/liter bottle (no mixing required) lasts quite a while. If I run out, I just get an additional bottle. I wouldn't go crazy with stocking up and I wouldn't go crazy using a lot of product unless you have lots of plants.

This is an old thread (2006). I also posted a comment in 2011, mentioning that my SINGLE tomatillo plant did fine previous year but my 3 plant are not fruiting, as of the end of June. Once again, there are posts written by the gardeners who mention their sole tomatillo plant is doing fine. This puts the "self incompatibility theory" in doubt. I have experimented single plant , 3 times in the past plus this season. YOU DON'T HAVE TO HAVE MORE THAN ONE PLANT unless you want more fruits. Read my thread titled "Tomatillo, Facts and Myth" if you like.

"Can and should tomatillos be pruned " Ideally, no. It sounds good in theory but doesn't work in practice. In reality the more you prune it the taller it gets. You'll find many discussions about this question over on the Growing Tomatoes forum here. But pinching off early blooms isn't "pruning". In most cases the plant would have dropped those blooms anyway since it is already highly stressed. If it is already "long and leggy" then it isn't getting nearly enough light. If you can't plant it out soon and plant it deep then root cuttings off of it to use in the garden instead. Dave