Hydrangeas! One of our largest and most floriferous collections of plants here at Yew Dell. Beginning in June, species of this large genus of shrubs begin to flower throughout the gardens and they continue throughout the summer. Do we have a bunch of those “pink and blue” ones? Nope. The Hydrangea macrophylla, or big leaf hydrangea, are just simply not reliable bloomers in this area year to year. One warm spell in winter followed by a cold snap can freeze their buds off and potentially eliminate any flowers for the next year.
So no, there isn’t a big collection of the “pink and blue” ones but we do have extensive collections of three other species of Hydrangeas that reliably bloom every year without worry about a bad winter. Let’s take a quick look at these three species, their bloom time, the time to prune them, and some of the cultivars that you can see around the gardens here at Yew Dell.
Smooth Leaf Hydrangea
Up first, Hydrangea arborescens (Smooth leaf Hydrangea). This is our only native hydrangea to Kentucky and one incredible garden and landscape plant. You can cut this plant back to the ground in the winter and it will still bloom every single spring without issue. Take that “pink and blues!!!” Still want a pink blooming Hydrangea? Give‘NCHA7’ (Invincibell Mini Mauvette® Smooth Hydrangea) a try. Only growing to about 3-feet tall this plant is covered in bright pink flowers.
- Bloom time: June-July
- When to prune: Winter
- Sun Exposure: Shade to Part Sun
Oakleaf Hydrangea
Next, Hydrangea quercifolia (Oakleaf Hydrangea). Native to the southeast United States, this coarsely branched Hydrangea is another workhorse in the garden and landscape. Don’t prune this one at the wrong time. Like the “pink and blues,” oakleaf Hydrangeas bloom on old wood. This means that each fall they set their flower buds for the following spring. If you, or a deer, prune this plant back in winter it will not flower. Winter weather is never an issue but pruning at the wrong time is. If you do not want to lose a season of flowers make sure to cut back right after they flower in early July. Or, just plant a smaller cultivar like ‘Sikes Dwarf’, ‘Ruby Slippers’, or ‘Peewee’.
- Bloom time: June-July
- When to prune: July
- Sun Exposure: Shade to Part Sun
Panicle Hydrangea
Lastly, Hydrangea paniculata (Panicle Hydrangea). Although this one isn’t native to the U.S, it can be found in the woodlands of Asia, it is also a spectacular garden and landscape plant. This is another Hydrangea you can cut back to a couple feet from the ground each winter and it will still flower every year!
These have a wide range of bloom time. Here at Yew Dell ‘Dharuma’ is one of the earliest flowering, starting in late June. ‘Tardiva’ is our latest flowering variety, waiting until late August to open up.
- Bloom time: July-August
- When to prune: Winter
- Sun Exposure: Part Sun
What about pruning and sun exposure?
Pruning is always the biggest question we get with these plants, but with the simple direction above it is easy to prune these plants and still get flower each year. What about sun exposure? Shade, part sun, sun?!?!?! A lot of the answer can simply be answered by whether or not you can keep them well irrigated during the summer. All three species mentioned prefer protection from the afternoon sun. Can an oakleaf hydrangea survive full sun in a parking lot island? Yes, but it doesn’t want to be there. In these more harsh, sunny environments water is going to be key to keeping them healthy and happy during the summer. The best bet? Give them all a good amount of morning sun, afternoon shade, and a slow soak of water during dry spells.