Expert: C.L. Fornari - 7/12/2006

Question
I currently recieved 2 blue hydrangea plants, they were so beutiful, I planted them and they are dying or maybe even gone already. I read th instructions and know that I needed special fertilizer for them, so I purchased mircle grow specifically for the hydrangea and they still are dying? Can I still save them or is there anything else I can do? P.S.- I think they are annuals which mean they should come up every year?

Answer
Rebecca,
Hydrangeas are shrubs, and they come back every year.  Some types bloom on both old and new growth, and others only bloom on old growth...this means that no matter what type you have, they will form flower buds on the stems that they have right now.  So never cut the stems down to the ground...the best rule of thumb is to only remove dead wood (canes with NO leaves on them - or parts of canes with no leaves on them) and do this in the spring when the new leaves are about the size of quarters.

As to what is killing your plants now...the most likely problem is too much or too little water.  Too much water gives the leaves black spots and the leaves turn yellow and fall off.  Too little water and the plant wilts, the flowers turn brown.

The other possibility is fertilizer burn.  If you mix fertilizer too strong, or fertilize a thirsty plant, the edges of the leaves turn brown, the flowers shrivel and turn tan/brown, and leaves fall off.

At this point I'd do the following:
1. no more fertilizer for this year. (contrary to the fertilizer labels, plants DON"T need to be fertilized every time you water - annuals, which are plants that die after one season, can use fertilizer every two or three weeks, but twice in the season is plenty for shrubs like hydrangeas.
2. Water deeply less often - hydrangeas like more frequent water than most plants, but in all but the hottest of regions they can go four days between watering.  Water by wrapping a soaker hose around the plant and turning it on for a half hour - don't hand water... people get bored long before the plant gets enough moisture.
3. Put an inch layer of compost or composted manure over the surface of the soil around the plant - this will amend the soil from the top down and help it to have the right amount of moisture for your plant.
4. Don't cut off any stems that might look dead until next spring - follow pruning guidelines above.

I hope this helps!

all the best,
C.L.