Expert: Mike Mascio - 8/10/2004

Question
my purple wave petunias are spindley. HOw do I make them much fuller like all my neighbors? I dead head them daily. Is that wrong. Sometimes I pick the whole green part as well and other times I just pick the flower out. I have always had good luck growing them, just not getting them full. The neighbors never do anything to theirs and they look beautiful!! I have used fert. on them most of the summer (once a month). I have stopped fert. them. Any suggestions for next year?

Answer
Cheryl, it is not too late to cut them back for one more flush of blooms.  When petunias receive too much fertilization, especially with a fertilizer high in nitrogen, they can become spindly.  To correct this, you must prune them like a bush, shaping them into a round mound.  I would suggest cutting the plants back by a third.  They should then develop a bushier habit and bloom one more time before your first frost.

Next year, use a fertilizer high in phosphorus and potassium, but low in nitrogen.  Phosphorus encourages blooming, while nitrogen results in taller plants and more foliage.  Also, add organic amendments to the soil this fall such as shredded leaves, compost, peat moss, and aged manure.  This will help improve the soil and neutralize any imbalance in your ph levels.

I hope this helps.  Good luck, and enjoy the rest of the summer.

Regards,

Mike