This spring I planted seven hydrangeas – three ‘Annabelle’ and four ‘Limelight’. The intention was to provide a continuous display from early summer through fall, with the huge round white flowers of ‘Annabelle’ appearing from June through late summer, and ‘Limelight’, with its green blooms slightly tapering acid, beginning in late summer. and changing color to ivory then flushed pink before fading in late fall. A good combination.
But there was a catch. I planted them all on the west-facing length of the long orchard beds which I widened last winter, so they would have the dappled shade they like from the apple trees and also take advantage of the rain that always blows from the west in this part of the country.
But, as we all know, the rain never came. I planted them in March, watered them well and then a very dry spring was followed by the driest summer in over 40 years. The trees sucked up all the available water and the shrubs only survived because I watered them spot on every few weeks, but they didn’t thrive.
No matter. Their time will come. However, it exemplifies what hydrangeas like best, which is light shade and a generous, steady water supply, along with rich soil and good drainage.
Hydrangeas in Giardini Reali in Venice
My choice of the two varieties was heavily influenced by a visit to the Giardini Reali in Venice, where both hydrangeas are used to massive and exceptional effect. ‘Annabelle’ is a cultivar of H. arborescens, native to North America.
The flower heads are huge and dramatic, so they make a big impression even when young. It reaches 1.5 m in height, with the same width, but can be pruned to its space. It should be pruned in the spring, and the harder you prune – even cutting down to ground level – the larger the flower heads.
The only problem is that the flower heads are produced on new wood, so pruning the flower heads on unripe stems can cause them to fall off.
H. paniculata ‘Limelight’ will grow, like ‘Annabelle’, in most soils as long as it has good drainage. It was bred in Holland in the 1990s and can grow substantial, reaching 3m or more in height and width.
The acid green flowers of ‘Limelight’
If pruned annually, it will still show up to 2m of growth during the season. It also flowers on new wood, so can be pruned four or five buds above the base each March.
I would recommend planting hydrangeas in the ground over the next month rather than waiting, as I did, until spring. This will give the roots time to establish themselves before new growth begins in the spring and they will be better able to reach the moisture in the soil.
One caveat: if you have the more traditional H. macrophylla, whether mop-headed or lace-headed varieties, don’t prune in winter.
Their buds form in late summer, and faded flowers form an important protective layer for them, so they should not be removed until the last frosts. When pruning, cut back to the first pair of healthy buds. Any old, through, or dead wood should be cut down to the base of the shrub.
MONTY’S WORK OF THE WEEK
Garlic can be planted any time in the fall, but cloves planted in September have the best chance.
This is especially true for hard-necked varieties such as ‘Lautrec Wight’ (above). A second planting of soft-necked varieties such as ‘Early Purple Wight’, which grow faster, can be done any time up to Christmas.
Plant individual plump seed pods 15cm apart, pointed end up and with the top 2.5cm below the surface. Garlic does best in a sunny position in well-drained soil that contains plenty of organic matter.
Many years ago I planted a 30 cm high conifer (left) 1.5 m from our detached house. It is now 6m tall – are the roots a threat to the building?
John Mullin, Glasgow
A general rule in tree planting is to plant it at the ultimate height of the tree away from the house – so a minimum of 6m in your case. If the foundation is good and the soil well drained, you should be fine. However, if the house has a poor foundation on clay soil (as is the case on many downtown Victorian streets), encroaching roots could cause cracks. If you are worried, remove it and next time plant further!
I lost most of my Buxus to box tree caterpillars. I don’t like to use pesticides, but I have only three bushes left and I remove the caterpillars by hand.
Linda Worby, Clacton-on-Sea
The vaporizers do not work. Pluck them, or better yet, catch the parent moths at night before they lay their eggs. The prognosis is not good, I’m afraid.
I accidentally sprayed weedkiller on the roots of my privet hedge, which created a “dead zone”. What can I do?
Peter Reed, Grimsby
Your best bet is to dig up the roots of the affected area, add compost, and replant with healthy young bushes. They will soon fill the hedge.