Question
Hello my name is Alex I'm in SW Ohio so I'm not sure what zone that is. I have a beautiful Hydrangea bush in my front yard that was here when I moved. The first 3yrs or so I had no problem with blooms, last year no blooms at all. Some time last year I broke off the dead stems and this year I have a beautiful range of pink, purple, light blue and dark blue all on one bush! I don't know anything about gardening and I just want to know what I could do to make sure they keep coming back every year. I was told that I should prune them a certain time of year? And now this year the bush has spread alot more since last year, what should I do with it? Is it going to keep growing and growing?  The Hydrangea bush is surrounder by a bush to the left and a little flowing bush to the right in front of the Hydrangea.  Thank you in advance for any guidance and suggestions that you have.

Answer
Sounds like a really beautiful shrub you have there, Alex.

Pruning is tricky with Hydrangeas so make sure you know what you are doing when you pick up the clippers.

What could go wrong?  Hydrangeas bloom on second year wood. If you clip your Hydrangea now, you will probably lose all the buds for next year.

Any chance you did that two years ago -- and lost the summer's blooms?  Think back.

The colors on your Hydrangea are truly beautiful - I get the same colors and I really love them.  Coloring is determined by the genes, but further determined by soil acidity.  Acid soil renders the flowers more blue.  Alkaline soil produces pinkish flowers.  The change is gradual, a season or longer, so if you water your Hydrangea for the next 3 weeks with water and vinegar, you still won't see any noticeable blue-ing of the blooms any time soon.  

At my house, where food is never wasted, we pour unused but nonfresh juices and leftover black coffee on the Hydrangea.  Every little bit counts.  

DO NOT fertilize with Mir-Acid.  You will be pushing a button that says "More Leaves" instead of "Blue Flowers".  Regular watering with a gallon of water and a teaspoon of vinegar will bring more blue into the petals -- eventually.

Keep the shrubs around your Hydrangea well pruned, lower is best.  Your Hydrangea needs all the sun it can get.  A little Superphosphate scratched into the soil (make sure you don't put too much down and water it in well) will boost the size and number of buds, because Superphosphate is pure flower food.  Triple Phosphate is also a great choice.

At the very least, you can cut off the spent blossoms as they fade to keep your Hydrangea from expending its resources on seed production.  

If you want to keep it compact, cut back a few of the longest canes to the first set of leaves, or at least 15 inches from the crown.  But not too many -- you don't want to lose the next years' blooms.

Thank you very much for writing.  Let me know if you have further questions.