Gardening with Gary

Gardening Advice from an Expert

Hedges

John writes~ I have a hedge that is about 35 years old. My gardener can't seem to trim it evenly. Over the years, the hedge has also gotten very wide. It stays green and seems healthy. It is very woody inside. If I trim it down (by hand) and trim the sides will it die on me? I realize this is hard to answer because you have to see it.

A. Keep in mind the age of the hedge. Imagine any of us growing and struggling with Nature all that time and not needed a bit of help! I know I need a good trim quite often.

Your gardener is doing an easy job but not very well. If he had been well-trained in Horticulture, he would know that a simple uneven trimming is not good for an old hedge.

I want you to go ahead and even it out as you have suggested. But, not drastically, please. That would shock it and since the plant has gone so long without a proper pruning, you have a lot of work ahead and no need to try and get to square one all at once. I want you to go all along the sides and tops and take off a little bit. I am unaware as to where you live, but winter is not the time to do this, in the Northern Hemisphere.

Early spring is when I want you to do the first trimming. Take sharp, clean hedge trimmers and also remove some of the dead inside wood. Exposing the center to the sunlight will allow new growth to then sprout and fill in.

Wait a little bit, but not after the new growth has begun to pop. You do not want to cut that off. Shape it well before this time and then allow to grow. Start applying a good general gardening fertilizer, as a 20-20-20, every 2-4 weeks, diluted according to the label.

Then, later in the early summer, go through and trim out some more. Remove more dead inside wood, but do not take so much as to make a totally hollow center. That just may never fill in. Use discretion and common sense. You are not going to kill it if you proceed cautiously. But, if you leave it as is, you will risk the dying off of the entire hedge.

G.G. South writes~ What kind of hedge is quick growing, thick and most of all cheap?

A. Depending on light and climatic conditions, you have several choices if you want an evergreen.

Arborvitae, which like sun or mottled sun.

New hedge which I love called "Ilex Chesapeake" which likes shade or mottled sun and is a member of the holly family. It gets wide and high and has a small, waxy dark green, thick shiny leaf, but it grows fast. This is a beautiful pyramid shaped tree that doesn't lose it's lower branches leaves as it grows, unlike pines, an unwise choice for a hedge. I have planted several on the front of my property and I can attest to their vigor and quick growth as well as ease of growing. They are a beautiful hedge which grows quickly and add they a dark green background of superior quality. Unlike a regular holly, Chesapeake leaves have no thorns and are similar to a boxwood's leaves except thicker and waxy. They are tall and do require pruning for shape, if you want perfection. Ilex Chesapeake are relatively new as a hedge. To my knowledge, there are no diseases associated with this species as opposed to hemlocks which are threatened by a spreading disease [see below].

Arborvitae, yew, or large ornamental grasses such as miscanthus. There are species that grow over 8' tall and retain their dense, bushy foliage all winter (turns golden brown).

Thuja "green giant" advertised to grow 3-5 ft/year. Nice.

"Blue Stallion" & "Blue Maid" Hollies that are pretty fast growers and relatively reasonable.

Lilacs, willows, rugosa roses, forsythia, Russian olive, mulberry and honeysuckle. All these a pretty fast growing and within a few years grow from rooted cuttings to 6' tall. This row is kind of neat because it attracts birds all year round. All these are very fast growing shrubs/small trees.

Leland Cypress trees, usually they grow 5' in a year.

Hemlocks [unfortunately, the woolly adelgid (a destructive sap-sucking insect from Asia) infestation is sweeping across Northeastern US. The only way to save infected hemlocks is through using the insecticidal spray or oil-based organic treatments. On smaller trees, it is doable, but on a full-grown hemlock, it is a big job which must be repeated annually.]

Oleander will grow very fast and is drought tolerant. Needs a moderate climatic zone though. Great out here.