Having some problems with heirloom strawberries in the winter greenhouse.

Starting with five plants, an heirloom called Fort Laramie, I propagated about twenty from runners. The original plants, in hanging baskets, are densely leafed and put out clusters of blooms. But the flowers turn brown and any fruit they set either shrivels or rots on the stem.

Soil problem? Disease? I'm puzzled.

It sounds like complete lack of pollination.
Try hand-pollinating the flowers: strawberries are self-fertile but need help moving the pollen from the anthers (male organs) to the pistils (female organs). A small clean brush is usually enough to do the trick.

Thanks! I'll give that a go.

Tried pollinating with a brush. No result.

Lots of big flowers but none will set fruit. This variety is day neutral and said to yield well in spring and fall.

Started with five plants and propagated about twenty-five from runners. That's worked fine before.

I've just noticed: Medicine Bow Range may be a bit on the cold side for unprotected strawberries.