Green Scene

Follow the Basic Principles for Landscape Planning: Green Scene

Gardening is not an exact science. Experts do not agree on whether Foster's hollies are parthenocarpic.
Gardening is not an exact science. Experts do not agree on whether Foster's hollies are parthenocarpic. (Sandra Leavitt Lerner For The Washington Post)
By Joel M. Lerner
Saturday, May 8, 2010

Over 40 years doing landscape and design work, and more than 13 years writing this column, I've picked up some valuable lessons. They might be thought of as principles for planning and managing your landscape.

Think ahead: Anticipate growth habits when planting trees and shrubs so they will increase in ornamental value as they mature. Don't install plants for instant gratification. For example, don't plant a two-to-three-foot-tall woody plant, such as a juniper, holly, spruce or cedar, 18 inches from the edge of a walk or wall. In maturity, that plant will spread to eight feet or more, blocking entries, lifting walkways. Except for hollies, these plants are difficult to prune because of their growth habits and do not renew well. So if they are planted too close to structures or too close together, they will shade one another and lose ornamental value within several years. Site plants far enough apart so sunlight will reach the base of the plants, allowing them to develop to their maximum potential.

Have patience: Gardens grow one day at a time. Groves of magnolias, dogwoods, river birches, sassafrases and staghorn sumacs can become eye-catching art objects growing in groupings. With maturation, their sweeps of colors in spring and fall can be breathtaking. Flora can languish or become dormant, like the shade-tolerant perennial snakeroot (Cimicifuga racemosa). It seemingly died when we planted it one spring. It reappeared a year later and has been vigorous ever since. Flea beetles destroyed our black-eyed Susans. We didn't replace this perennial, as advised. Two years later, the black-eyed Susans returned, probably in large part from seed. They have remained pest-free and displayed dense flowers.

Practice stewardship: Sites must be prepared before planting. I mix one part compost with two parts native topsoil to ensure good drainage and air circulation. Gardens require care while plants are establishing. Newly planted trees, shrubs and perennials need water in summer when there is no rainfall for a week, and beds around perennials and the bases of trees need weeding. Only the crossing and lower limbs of trees, deadwood and sucker growth require removal. Other plants might need dividing, deadheading, selective pruning, or in the case of overly aggressive ornamental plants, hacking back if they become uncontrollable.

Design your landscape: Ideas are best placed on paper as circles to suggest an idea of what you visualize for your garden. Plant with a design in mind, but count on a decade for your garden to mature into what you visualize. It will be time-consuming and involve successes and failures.

Accept that it's not an exact science: Garden designs often work when you least expect they would and fail when you're certain you chose the perfect plants. Carl Orndorff, the late, award-winning nurseryman, would frequently say to me, "They don't know what they are talking about," referring to academia and textbooks. He did not believe in using fungicide, and instead advocated planting where plants would have room to grow with open habits and good air circulation.

Start with a soil test: Healthy soil is determined by a test, usually accomplished at a state university through your Cooperative Extension Service. Tests reveal pH and nutrient levels and texture. If you request a test for specific plants, suggestions will be provided for amending the soil to meet their needs. To find a Cooperative Extension Service, go to

Plant selectively: Choose plants that you see at garden centers, provided they are healthy and out of the ground in containers or root balls. Never install more than you can maintain. Start with a couple of small trees and a perennial border.

Know your weeds: The most popular request from home gardeners is low maintenance. Unfortunately, this means attention throughout the landscaping season and pulling weeds such as porcelainberry (Ampelopsis), bush honeysuckle, multiflora rose, wisteria, kudzu, mallow, mustard, bittercress, nutsedge, henbit and bog smartweed (Polygonal setaceum) when they are young. Weeding and pruning take conscientious attention.

Conserve water: An important component of keeping maintenance needs low is watering. One water-conserving approach is utilizing rain barrels. You'll find a wide selection through an Internet search. Another helpful method of water-efficient landscaping is mulching with one to two inches of compost, topping with a veneer of aged shredded hardwood bark. Amend the soil with generous amounts of compost, and plant tough, native ornamentals that have always grown in this region so they have already adapted to our precipitation levels and climate.

Take risks: Try new plants; they will let you know whether they're happy. They didn't read the book that called them "problem free" or stated they grow only two feet high and wide. Accommodate whatever you try. If it doesn't work where you thought it would, try it somewhere else or scrap it for another plant. Sometimes colors clash; plants become invasive or they never flower.

Remember, there isn't only one right way to practice horticulture.

Joel M. Lerner is president of Environmental Design in Capitol View Park.

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