I’ve had a few questions about hydrangeas.  What causes hydrangeas to bloom on the old wood?  After talking to the LSU Ag Center, my best answer is that they were pruned too late this year if they didn’t bloom.  Hydrangeas need to be pruned in February or March.  This time of the year we need to winterize them by making their roots are mulched in by either pine straw or mulch.  Doing this will protect the plant.  That makes it simple for now.

When spring comes fertilize with a complete fertilizer like a 13-13-13.  There are ways to control the color of the blooms.  For white blooms use magnesium sulfate as an additive to your fertilizer.  Not only making a color difference in your plants, magnesium sulfate is an effective, soluble source of magnesium that helps prevent and control chlorosis (yellowing of plant foliage due to magnesium deficiencies).  Apply at the rate of 1 lb. per 100 square feet and water thoroughly.  Use aluminum sulfate to get blue hydrangeas.  Use 1 lb. per 3 foot of height.  Mix 1 lb. in 5 gallons pf water and apply at the drip line of the shrub.  Aluminum sulfate can also be spread dry around the drip line and watered in.  

So, now we have a plan. Winterize with mulch or straw, prune in February or March, and fertilize with a complete fertilizer in the spring.  With that said, our hydrangeas ought to be beautiful in the spring.

(Mitzi Thomas owns Minden Farm & Garden LLC. Watch for her column on Fridays in Webster Parish Journal. Email Mitzi questions at  mitzithomas40@yahoo.com.)