Question
I planted 2 hydrangeas about 4 years ago. (1 white, 1 blue)
They never bloom.  The foliage is very healthy and the 1 has grown rather large.  It all dies off in the winter leaving the canes sticking up until summer(zone 6) The new leaves start growing and the plant gets very healthy looking with lots of leaves.  I leave the old canes.  We never get any flowers.  These get about 3-4hrs of morning sun, then shade.  Should we try to move them or are we not pruning them correctly, or????  Thanks.

Answer
Diane, it is important to prune the hydrangea in early spring, before the plant produces buds. This includes cutting the dead canes as far back as possible. This will promote a stockier growth habit and also stimulate blooming. In early fall, prune the entire bush by 1/4 to promote buds for the following spring.

It is also important to grow hydrangea in soil that is slightly acidic; generally with a ph level at around 6. You can purchase a ph meter that will give you the current level for your particular soil. These test kits are relatively inexpensive and very accurate. If the soil is above 6, you can add gypsum or sulfur to the soil to lower the ph.

Finally, hydrangea needs soil that is fertile with a high level of phosphorus for blooming. You can accomplish this by adding organic amendments to the soil such as compost, humus, and aged manure. You can also supplement feeding is early spring with a ware-soluble or granular fertilizer with a high ratio of phosphorus. Phosphorus is the second number on the fertilizer label. It should be at least double the ratio of the first number, which represents nitrogen.

I hope this answered your question. Good luck, and please write again if I can ever be of assistance.

Regards,

Mike