The lone voice of horticultural reason

Orange Pines

Last year, my yard received no measurable precipitation from August 12th to the end of the year. Measurable precipitation to me is enough rain collected in my wheelbarrow sitting out wherever I left it to warrant dumping it at the base of the nearest shrub the following day. It’s right around one-half inch.

Homeowners should be aware that today there is darn little moisture in the ground you own. What surprises me is how adults who wouldn’t dream of driving the Lexus one mile over 3,000 before having the oil changed treat the evergreens on their property as if they were maintenance-free. In times of normal, regular rainfall, most of the trees and shrubs on your property will survive and even prosper. In times of drought, however, many, particularly the evergreens, will die, as evidenced by the rust-red junipers, brown Arborvitae, and orange white pines I witnessed last week driving around lake Minnetonka.

We quite often plant the wrong tree (or shrub) in the wrong place. We fall in love with white or red pines during our travels north, and decide we must have one in our front yard in the suburbs. But how do pines grow in the wild? In forests, stands, and drifts. They shade one another in their natural habitat.

What’s the floor like in a pine forest? You can walk around the trees pretty much anywhere you want to go, because there’s very little underbrush competing for moisture. Underbrush gets shaded out due to the great height and girth of the pines. You walk on a carpet of pine needles, a natural mulch that further helps contain moisture in the soil.

In the city and suburbs, we plunk one white or red pine down in full sun, often in a heavy soil, and surround it with grass. If we plant more than one, we space them widely apart. The sun beats down on the tree(s) all summer and winter, and in the growing months, the grass sucks all the moisture out of the ground. Pines have a very shallow root zone. The grass wins. It takes a long hard rain for moisture to penetrate down six to ten inches, into a pine’s lower root zone. Without heavy watering at the time of planting (plant in early spring or early September) and regular watering once a week during the first two years after planting, pines either don’t survive or look ratty during their hard, troubled lives.

When we have a dry fall similar to last year’s, the trees “go to bed” (slowly taper off growth into winter dormancy) dry and stressed out. Then we get a mild, sunny winter. Above ground, at some point in January, February or March, pines sit in bright sun in 35, 40, or even 50 degrees (it was 72 degrees on March 5), and the cells in the bark and needles come to life.

And what do all plants do in their active state? They transpire, or lose water through their needles, or leaves. There is no moisture in the ground or in the roots to replace it, so the needles dry out and die.

The solution? For pines, particularly white pines, plant them in a sunny spot where they’ll receive some afternoon shade. Don’t plunk them down all alone on the south side of the house. Dig as wide a hole as possible. For new construction, rototill the hole out five-feet on all sides-a ten-foot diameter hole. If the soil you’re dealing with is inert, desolate, sandy, rocky, junky crud, amend it with a moderate amount of organic matter, such as compost. If it’s fairly decent mineral soil, you can probably leave it alone.

Water pines all during the growing season, particularly in the fall, straight up until the ground freezes, which can be as late as December.

Create a six-inch thick layer of shredded bark from the trunk out all the way to the drip-line and preferably beyond. Keep it out an inch or two from the trunk, however. Fertilize the poor thing with a granular evergreen fertilizer in the spring and again in mid-summer, or once in late fall and again in mid-summer the following year, starting the first full season after planting.

Add up the replacement costs of the shrubs and immature trees on your property should they die, and the figure could well exceed the cost of that Lexus. Take care of all your possessions. This is not work. This is gardening.

Don Engebretson
The Renegade Gardener