Getting the Blooming Hydrangeas of Your Dreams!
Warm climate gardeners have been enjoying hydrangea flowers for several weeks. Cold climate
gardeners, on the other hand, are just now seeing the buds and blooms on their bigleaf hydrangeas (macrophylla). Alas, however, some may not be seeing anything except either dead stems or live stems with no flowers. So what happened?
7 Tips that Answer “Why Aren’t my Hydrangeas Blooming?”
#1- Properly Siting your Hydrangea
Bigleaf hydrangeas need a half day of sun, ideally in the morning.
Don’t fret if all you can provide is afternoon sun; you can still get flowers. You just need to keep an eye on the moisture level in the soil so that there is enough for them to rehydrate when needed.
The more important part of their siting is to protect them from winter conditions as best you can. To do this, consider planting them in the protection of winter persistent barriers like evergreens (conifers, rhododendrons, azaleas) or plants that hold their browned-out leaves like beeches, parrotias, and oaks. Other barriers could be a fence, a neighbor’s house, a shed or even an Adirondack chair or other lawn furniture turned sideways to block the prevailing cold winds and icy precipitation.
#2 Ensure your plants are strong and healthy enough to produce flowers
Producing flowers takes a lot of energy from the plant so you need to make sure they are well fed. You do that by fertilizing your hydrangeas, ideally in the spring up until about August 1. Rose fertilizer or a granular shrub fertilizer have the right mix of nutrients to do the job.
#3 Check to see that your hydrangea isn’t getting nitrogen from an adjacent fertilized lawn
Too much nitrogen can be a problem especially if the plant is downhill of that lawn or if a rotary spreader is used to fertilize. If that’s the case, that “casual” nitrogen that your hydrangea is getting is encouraging it to make leaves and not flowers. See if you can either move the plant or somehow prevent that fertilizer from reaching the roots.
#4 Take a look at your watering habits
It’s a normal reaction to water your plant when you see it drooping from being in the sun. Most times, additional watering won’t be necessary as hydrangeas rehydrate as soon as the sun is off them. They reach back into the surrounding soil and perk back up within a few hours. Consider holding off on any spot irrigation until the sun is off the plant to see if it snaps back. You might have to wait until the next morning. If it is still flagging, then, by all means, go ahead and give it a drink.
Keep in mind that excess water in the roots can rob your plant of necessary oxygen and rot it, eventually killing it. But more importantly, too much water will cause your plant to make leaves and not flowers or even kill it. Oops — and you thought you were saving it!
This photo shows a plant at two different times of a typical day: you can clearly see how it recovers.
#6 Pruned Your Hydrangeas at the Wrong Time
Of course, the most common reason your plant might not flower is it was pruned at the wrong time. Your bigleaf hydrangeas start to develop their flower buds for next year from about August 1 onward. Those buds take several weeks to form and then stay on the stems until the following season. Anytime you prune that plant between August 1 and when you see the buds – not just the leaves – you run the risk of cutting off “sleeping” flowers.
Despite the fact that those stems look dead, most are alive. You can test a stem’s viability by scratching it: if it shows green, it’s alive as in this photo.
Take heart, however, you can save your season and get blooming hydrangeas from seemingly barren plants. The way you do this is to grow bigleaf hydrangeas that rebloom more than once since rebloomers have been bred to produce flowers in the current season. Those flowers come either from a newly grown stem or from sleeping buds from last year that made it through the ups and downs of the prior six months.
Reblooming stems that deliver flowers along their length look like this:
# 7 Weather Conditions affect Blooming Hydrangeas
If cold and/or fluctuating temperatures are your enemy, you can avoid all this angst by growing hydrangeas that bloom only on new wood. They are foolproof as the flowers come only from stems grown in the current year. All woodland/smooth varieties and panicle hydrangeas fall into this category. They still need the right fertility, cultural conditions, and pruning smarts applied to them. ‘Annabelle’ and ‘Limelight’ are two such examples.