Hydrangea Not Blooming?

Dear David,

My hydrangea has never bloomed. I’ve tried everything - a soil test indicates the soil is extremely fertile, with no obvious nutrient deficiencies. I also fertilize the bed every season. This season I cut it back to encourage new growth, but still nothing.

Is it time to rip it out and try something else?

Laurel, MD

Dear Laurel,

Are these Hydrangea macrophylla - one of the usually-pink-or-blue varieties? There are a bunch of different kinds that grow well in our area, but it's hard to imagine the other varieties we've grown failing to bloom.

H. macrophylla are well adapted to a variety of soil conditions. Some cultivars famously turn pinker in alkaline soil and bluer when it's acidic. Our garden's soil is pretty acidic, which suits me fine, because pink!

Our soil is also extremely well-drained (lots of sand), which led to a problem with the plants not getting enough water. I wrote a piece at the time suggesting a hydrangea that isn’t thriving always needs more water, but it turns out there are a few other ways to get sideways with them.

So here's what you're going to do first: stop fertilizing, and stop cutting back. Too much nitrogen signals the plant to leaf instead of flowering, so back off. We do fertilize ours a little bit after flowering most years, but never in the spring. And as for cutting back - H. macrophylla blooms on "old wood." This isn't true of all hydrangea, so if you want something that likes being cut back, plant H. arborescens or H. paniculata. We love "Invincibelle" and "Little Lime" cultivars. But if you're sticking with the macrophylla, only cut back dead wood in the early summer and never cut back during the winter or anything green.

Finally, if that doesn’t work, try moving it. Maybe it just doesn’t like where you planted it. Plants take a long time to move themselves, and but the help of a gardener if the process is to go faster.

Warmly,

David