Ask the Gardener: Try the Japanese mountain hydrangea for smaller yards
Q: I have a small yard and would like to plant a smaller variety of hydrangea. What would you recommend? And have you seen a hydrangea thrive in a pot? Is it too late to plant now? -J. Sullivan, Raleigh
A: The Japanese mountain hydrangea, Hydrangea serrata, is a smaller plant than most other species, only growing to about 3 feet tall and somewhat wider. Most of these have lacecap flower heads in shades of pink to blue and white. One of my favorites is especially compact and is known by its wild collection designation Wilson 7820. While this form isn’t widely available, it can often be found through specialty mail-order nurseries.
Hydrangeas are just fine in containers provided that you can keep them watered during the heat of the summer. As for planting, if you purchase a dormant hydrangea, it would be just fine to be planted now. If the plant is in active growth, it would be best to wait until spring.
Q: In the question from Jan. 21 about planting tulip bulbs, the suggestion was to plant Tulipa clusiana, which would come back each year in our region. Whenever I plant tulips in the ground they never even come up once. But I have lots of fat voles. Could there be a connection? (I plant tulips in pots and they do come up.) - A. McNamara
A: Voles are likely your problem if your tulips aren’t coming up in the spring. Next fall when you plant your tulips, try putting a handful of gravel on top of each bulb as you plant. Voles prefer not to dig through rocky soil and will leave your tulips alone.
Q: Do you have any advice for the best planting area and care of peonies? I have tried to grow them with little success. Either their buds drop or they get spots on the entire plant and die. Is full sun required? - J. Sullivan, Raleigh
A: In general, peonies really do prefer lots of sun to perform their best. There are quite a few leaf spot issues common to peonies and shady, so locations can exacerbate the problem. Plant your peonies in full sun and with good air movement to reduce your problems with leaf spot. Bud blast, where your flower buds fail to open, can happen if your plant is in too much shade or if it is planted too deep. The peony crown should be planted just at the leaf surface and shouldn’t be mulched deeply.
If you have nothing but shade and would still like to grow peonies, try the more shade tolerant species, Japanese woodland peony (Paeonia japonica) with white flowers or the pink Japanese woodland peony (Paeonia obovata). Both of these species thrive in light shade. The white species adds an extra season of interest with metallic blue seeds held on red stalks in fall while the pink one bears bright red seeds in autumn.
Plant Spotlight
Common name: Wilson’s compact mountain hydrangea
Botanical name: Hydrangea serrata (Wilson 7820)
Family: Hydrangea (Hydrangeaceae)
Category: Flowering shrub
Primary uses: Woodland gardens, containers
Dimensions: 30 inches tall by 48 inches wide
Culture: Part sun to shade. Hydrangeas thrive in light shade with moist, well-drained soil. They are quite attractive to deer so they may need protection especially when young. This compact form should not need much pruning other than to thin out some of the oldest stems every 3-4 years.
Bloom time: May to June
Color: Pink in alkaline soils, blue in our typical southern acidic soils.
General attributes: Although this form of Japanese mountain hydrangea has never been given an official name, it has been passed around and sold as Wilson 7820, the collection number of noted plant explorer E.H. Wilson. It is a diminutive form of the already small species, H. serrata. It is exceptionally tough and easy to grow and seems to tolerate dry spells once established with less leaf burn than many other forms.
This story was originally published February 17, 2017 at 9:00 AM with the headline "Ask the Gardener: Try the Japanese mountain hydrangea for smaller yards."