Getting Tomatillos to set fruit

[realfood]

This year I tried tomatillos in the greenhouse and they have grown very vigorously, now well over 2 m tall and climbing out of the windows as well.
They have carried thousands of flowers with copious pollen since June. I have regularly shaken the flowers to pollinate them, left the windows open to allow insects in, but it has only been in the last month that the flowers have been successfully pollinated. The question is why?
I know that others have had similar problems but no answers. I am now wondering if it is something to do with sensitivity to the daylight length, as in Glasgow we have long Summer days which are only now rapidly shortening.
In their natural habitat in Central America, they grow much, much closer to the equator and the hours of light and darkness will be quite similar.
Can anyone throw some light on this problem? ;D

[realfood]

[saddad]

I don't know any Solanums that rely on daylength to flower... tubers yes..  :-\

[GodfreyRob]

Doing a search on the subject indicates that there are two possible causes:

1. Need more than 1 plant to get a good fruit set.
2. Too much nitrogen can discourage fruit setting.

Here in Wharfedale I have grown Tomatillos for the past 2 seasons and have had no problems with the fruit setting inside or out (but I have always had several plants together).

[realfood]

I had 3 plants of the same variety growing together. I do not think that the ground was too nitrogenous as I used tomato feed.
From a Google search, it does seem that tomatillos are much more difficult to get to set fruit than tomatoes.