Gardener, the most common causes are:

Planting too late.
Lack of sunlight.
A fertilizer with too much nitrogen, and not enough potash.

We would have to have more particulars to determine which of these, or if something else was wrong.

mine are just coming into flower as i started them off later than usual. they will still fruit and ripen if you keep them warm.

Mine too...didn't plant the seeds till late! The flowers have only appeared this week.

Can someone tell me...do I now start feeding them? They are Tumbling Tom...not grown before.