Question
Our rose of sharon has hundreds of buds with pink showing but do not open up to a flower.  This is the second year this has happened.  What can we do?

Answer
When bushes drop their buds prematurely or do not flower as abundantly as advertised, it is usually an indication of inconsistent watering or a lack of phosphorus in the soil.

Be sure that you are not overwatering the plants. This tends to saturate the roots, which in turn makes it difficult to absorb nutrients. Also be sure to mulch generously around the plants with straw or dried grass clippings to hold in the moisture. Finally, only supplement enough watering to ensure 1"-1.5" of water per week.

The second problem can be the soil. Soils heavy in clay tend to drain poorly. This will result in the same problem as overwatering. Amend the soil this fall and again next spring with organic matter, including peat moss, aged manure, and compost.

Finally, be sure to feed the plants every 10-14 days with a fertilizer high in phosphorus and low in nitrogen. Nitrogen promotes lush foliage at the expense of blooms. Phosphorus, on the other hand, stimulates prolific blooming and strong stems.

I hope this answered your question. Please write again if I can ever be of assistance.

Regards,

Mike