Three Huge Landscape Mistakes
July 20, 2011
People who read web pages like this one or gardening articles in the newspapers probably don't need this advice. But for all your friends or relatives who are making these mistakes, here are some things that are often done wrong:
- Volcano Mulching
It is wrong to mound mulch up the trunk of a tree. Simply wrong. The trunk will eventually rot under the mulch, and insects will enter. Trunk cells are different from root cells. If you have a tree with the mulch piled high around the trunk, simply rake or pull the mulch away from it. Continue to do this until you expose the root flare. You may be saving the life of the tree.
- Stingy Holes
Sometimes the landscaper or gardener gets lazy and digs a hole just big enough to stick a plant into. It is done with great big tree root balls and little six pack annual plugs. Either way, unless the bed was already completely prepared with lovely topsoil/compost mix, planting that way dooms the plant for failure.
A planting hole should be dug as wide as possible but at least three times the width of the root ball. The edges of the hole should be roughened up (so it doesn't become a smooth-sided soup ball from which water can never drain). The backfill should be the loosened up soil mixed with compost. Then the plant has a chance to send its roots outward--the normal growth pattern for most plants.
In a tiny hole with straight sides your new plants don't have much of a chance to get a healthy start.
- Destructive Pruning
Incorrect pruning can eventually kill trees and shrubs and certainly detracts from their beauty and performance. These are just some of the ways that bad pruning is harmful:
(a) Pruning at the wrong time can prevent flowering for a season (a common occurrence when hydrangeas are pruned in September). Many spiraea, especially in business parks, condos or institution grounds, are clipped into a ball just when they're about to flower.
(b) Pruning can weaken a plant if many leaves are cut off just when it needs them to take in sunlight to produce energy to support root growth.
(c) Flat-topping or "clipping" to make evergreen or flowering shrubs shorter generally produces thick re-growth where the plant was clipped, and lots of sticks--with no leaves or needles--below.
(d) Leaving stubs--where a tree limb is cut between branches--is ugly and damaging because the limb cannot seal off the wound. The tissue simply rots there, and the diseases and insect activity proceed up the limb into the rest of the tree. The correct pruning cut is made right outside the branch collar, where there are active cells that handle the wound properly.
(e) Tree-topping is always the wrong thing to do. Utility companies or homeowners sometimes have to do it because they need to protect overhead wires, but this simply tells us the tree was planted in the wrong place. Topping a tree (cutting the tree's leader(s) off to make it shorter) results in weak, unhealthy growth that is easily damaged in the future. A formerly topped tree will never regain its full health and potential.
While people are extremely worried about the newest destructive beetle or disease of the year, the truth is that people kill more trees than any pest out there. Life is tough enough for landscape plants, so let's not make things worse with mulching, planting and pruning mistakes!