Hydrangea paniculata ‘Limelight’ blooms on new growth
Even seasoned gardeners seem to be confused as to when to prune Hydrangea.
Begin by identifying which Hydrangea species you are growing, to determine whether it will bloom on new growth or on old wood (last year’s stalks). The species arborescens, paniculata and some newer forms of macrophylla bloom on new wood. All the Hydrangea macrophylla (Mophead and Lacecap types) and quercifolia (Oakleaf) bloom on old wood, as long as there isn’t winter damage. Next year?s blossoms are set on the upper portion of the woody stalks in late summer and fall. H. macrophylla selections should not be pruned until after the plants have leafed out. In late spring, prune out or tip back any dead wood for a clean appearance.
The hardiest and most foolproof of all the Hydrangea are the paniculata group (Pee Gee types) and the arborescens group (Smooth Hydrangea). Both of these species can be cut within inches of the ground each spring if you want to control the size of your plants. They stalks can always be thinned to improve plant shape, and there is no harm to next year’s display if you want to cut long stemmed bouquets in summer and fall.
There are a lot of new Hydrangea macrophylla selections on the market, including ‘Double Expressions’, ‘Red Sensation’, ‘Let’s Dance Starlight’, and ‘Endless Summer’ that bloom on old and new wood. The blossoms appearing on old growth will display in early summer, while the flowers that form on new growth will appear later in August and September, for a long continuous display. If you live in the colder parts of zone 6 or zone 5, you may get too much winterkill for blossoms on the old growth, but you will still be able to enjoy a late summer through fall display.
Should you lime your garden?
Here in the northeast, we seldom consider the effects of acid rain anymore. Since most public water departments deliver water with a neutral ph, the effects of acid rain have been largely neutralized in landscapes that use public water. Still, we cant be certain of the soil pH unless we periodically test it. it is a good idea to purchase soil pH testers, either online or at a local garden centers.
Be on the lookout…there may be treasure in your garden.
During your spring cleanup, you will no doubt uncover all kinds of delightful signs of life: the healthy shoots of perennials, dozens of tiny seedlings or wiggly earthworms under fallen leaves. One treasure you should be on the lookout for, and not mistake as something bad is the over wintering egg case of Praying Mantes (or Mantids). These pale tan Styrofoam looking sacs are attached in the crotches and on the undersides of bare branches. In late spring they will begin to split, upon which a hundred or more tiny translucent Praying Mantes will unfurl and march away to devour a wide variety of your most irritating garden pests. We were absolutely delighted to learn that they voraciously eat grasshoppers, which are a nuisance we’ve had difficulty with in the past.
The Praying Mantis is a most fascinating insect to observe in the garden. They sit motionless in the garden waiting for their prey to pass by. And yes, it is true that the females practice sexual cannibalism, (but not always, we’re told). Often the male is just not thinking straight when he has copulation on his mind and surprises the female as she sits motionless. Her first reaction is to grab hold and bite off his head (she needs the extra protein for pregnancy!). The male is able to fulfill his mission nonetheless and we hear he dies happily ever after.
Tending to Hellebores in March
One of the first things we tackle in the garden is raking up windblown leaves that have accumulated around the crowns of the early blooming Lenten Roses (Helleborus orientalis hybrids) and removing last year’s tarnished foliage, which may harbor pesky Botrytis spores.
As you cleanup that decaying growth, you may be fortunate to discover dozens of tiny seedlings at the plant’s base (of course that’s if the Hellebore bloomed well for you last year). These seedlings may be variable in color, especially if you’re growing a hybrid selection or have more than one variety. You can always leave them undisturbed, and a few will eventually establish in situ or you can very gently lift the delicate seedlings and transplant them into small pots using a well drained potting soil. After a few months they will have put on enough growth for transplanting to other spots in your garden.