Overgrown housefront
Planting trees too closely to the house is a common gardening blunder.
Photo by George Wiegel
Good gardeners aren’t born with “green thumbs” that give them mystical powers to make any plant thrive.
Gardening is like any endeavor. The more you know, the more success you’re likely to have. Every setback can serve as a learning experience as well as evidence for the saying “Everything I learned about gardening can be found in my compost pile.”
One way to speed up the process is by taking advantage of the knowledge of those who have killed their petunias and dogwood trees before you. Here are seven of the most important woes that our “foregardeners” would warn you about:
Not improving lousy soil. If you’re blessed with reasonably good soil, just loosen and plant. But if you’re starting with soil that’s more sand, clay or rock than dirt, plan on some remediation. One school of thought advises rototilling or deeply digging the ground to at least 10 or 12 inches deep, then working about 2 inches of compost, rotted leaves or similar organic matter into it.
A second school of thought advises topping the landscape-bed-to-be with about 12 inches of wood chips and then waiting at least six weeks for decomposition to start. Then the chips can be pulled back to plant and redistributed around the plants as mulch.
You only need to do either of these once—before planting. From then on, just keep a 2- to 3-inch layer of organic matter over the surface, and let the earthworms and microbes be your soil improvers.
Planting too closely. This common blunder includes planting plants too close to one another, as well as too close to the house.
Crowding sets you up for a jungle look within a few years. It also sets the stage for unnecessary pruning and makes plants more prone to disease.
Determine the mature width of your plants, and space accordingly. A good rule of thumb: Add mature widths together and divide by two to find your minimum spacing. Example: When planting an 8-foot holly beside a 4-foot spirea—8 plus 4 equals 12, so divide 12 by 2, and you have a 6-foot minimum spacing between plants.
To space from houses, simply divide the mature width in half, so an 8-foot holly should go no closer than four feet from the house.
Too-deep planting. This one’s a major killer of trees. Planting deeply doesn’t make a tree less likely to blow over, but it will suffocate the roots and rot the buried bark.
Before planting a new tree, identify its root flare—the area at the base of the trunk where it begins to widen. Plant so that this flare is just above grade. Be aware that potted and balled-and-burlapped trees are often already planted too deeply in their pots and bags. You may need to excavate soil to expose the flare.
Poor planting practices. Go wide but not overly deep with holes when planting trees and shrubs. Dig holes three to five times as wide as the root ball but only as deep as the root ball. Fray out circling roots. Tamp the soil, and water well after planting.
Mulching miscues. Don’t overdo it with mulch. Two to three inches of organic mulch (for example, bark mulch, chopped leaves, pine straw, shredded hardwood) is ideal around trees and shrubs. One to two inches is fine around flowers. Be careful not to pack mulch up against the stems and trunks of plants. That can rot the stems and bark and possibly kill the plants.
Watering blunders. Your goal is to keep the soil consistently damp (never soggy) all around the root ball and just below it. That encourages roots to grow out toward the water without causing rot.
The best way to gauge the amount: Water slowly enough that the water soaks in instead of runs off for the amount of time you think is right. Wait 10 or 15 minutes, then use a stick or probe to go down beside the root ball to see how deeply the soil has been moistened. If it’s excessively wet, cut back next time. If it’s not wet deeply enough, you’ll need to water more.
Plants with bigger root balls, such as trees and shrubs, are best soaked deeply once or twice a week. Vegetables, annual flowers and newly planted perennials are best watered two to three times a week in hot, dry weather, since their roots are shallower and closer to the surface.
Picking problem-prone plants. Plants have their own particular site preferences, especially when it comes to light and soil moisture. A big part of good gardening involves figuring out where each plant will thrive. As for plants that you realize are struggling because you’ve picked the wrong site, don’t be afraid to move them—the sooner the better. Many green-thumb gardeners will tell you they’ve moved the plants in their yard a minimum of three times before they got it right.