Gardening: Summer is the time to do major pruning
Now and through the summer months is the time to do any major pruning or cutting back of shrubs and trees. With the fast, summer growth rate upon us the plants will regrow and look beautiful for next fall season.
Pruning of ornamental shrubs is done to improve their health and appearance. However, constant shrub shearing can kill an otherwise healthy shrub. Regularly shearing shrubs to the same height with gas shears will weaken them, make them leggy, susceptible to diseases and insect problems and eventually kill them. Yet, hedge shearing has become the norm in South Florida. People actually expect all of their shrubs to look like square boxes, round spheres or cones and umbrellas. They call it the “manicured look.” And because everyone is doing it they think it’s the right way to prune. It’s not! You can get away with it for a number of years and since the ruining process is so slow, when things start to go wrong no one thinks of the pruning practices as the problem.
When shearing a shrub you remove the terminal (end) growth week after week, year after year. A plant only has so many axil buds and dormant nodes to replace those lost to pruning. This new growth is important for plant health as they get their food (sugar) from the sun through the process of photosynthesis.
As new growth occurs, the hedge shearer cuts it off so as to maintain the manicured look and they prune off the food delivery system used for future food production. This food is used to produce more plant tissue and most of it goes to the root system. So imagine the poor plant with no food to the roots for overall vigor and then you use up all axil buds and dormant nodes for new growth -- well I think you get the picture.
You should prune to rejuvenate old or over-pruned shrubs by removing old stems and branches. This can be done every year and is a good procedure if the plant has become leggy, is growing out of bounds, or to remove the thick mat of dead terminal ends of branches created by over shearing. Most people will prune to maintain or develop a desired size or form. Selective pruning can shape plants and produce either a thin or thick canopy.
Plants are pruned by either heading back or thinning. Heading back is the selective cutting of the ends of branches to a bud. This procedure produces a denser shrub because it increases the number of shoots and leaves. When heading back make the cut on a slight angle, 1/4 inch above a healthy bud. The bud should be facing the direction preferred for new growth.
Thinning is the complete removal of branches back to the lateral branches, the main trunk or to the ground. Thinning gives a plant an open and natural appearance and encourages healthy new growth.
Removal of dead, weak or damaged wood, and disease and insect infested wood is an effective way to stop the spread of disease and insects to other plant parts or neighboring plants. Always disinfect your pruning tools after pruning diseased wood, using a weak bleach solution, to prevent the disease from being spread to healthy wood. Remove branches which rub and wound other limbs and remove weak, damaged or crowded stems.
Plants pruned into different shapes creating landscape oddities, such as animals, are called a topiary. Or you can grow plants against a wall which is called espalier which requires a special pruning technique. Plants trained in this manner are specimen plants and not all plants are adaptable to this technique. Pyracantha, loquat and podocarpus are a few that make excellent espalier plants.
For some shrubs, such as gardenia or croton, you should not use hedge shears but cut each branch separately using hand shears. This will maintain a neat informal shrub that retains its natural shape. Normally any plants with large leaves should be pruned this way. A properly pruned shrub is a work of art.
The method of pruning hedges depends on the type of hedge desired. Informal hedges consist of a row of closely planted shrubs which are allowed to develop into their natural shape. Annual pruning consists of cutting just enough to maintain the desired height and width.
Formal or clipped hedges require continuous pruning during the growing season. The desired appearance of a formal hedge as a soft outline of foliage from the ground up. Two important things to remember when pruning formal hedges are (1) hedges should be clipped while new growth is green and succulent and (2) plants should be trimmed so the base of the hedge is wider than the top. It should also be noted that constant over shearing of hedges can cause the tips of branches to die back and develop disease. Cocoplum and ficus are especially susceptible to this problem. Be sure you have something to prune before you put your shears to the plant. Hedges pruned with a narrow base will lose lower leaves and branches because of insufficient light. This condition will worsen with age resulting in sparse growth at ground level and an unattractive hedge which will not give the desired privacy.
When the wrong shrub is planted in the wrong place, it is often necessary to over prune to keep the plants from interfering with each other and growing out of the bounds of the garden. To avoid this costly mistake learn the mature size of the plants and then plant them in an area that will not require over pruning to maintain them in that area.
Your pruning tools should include the following:
- Hand pruners: Used to cut branches up to 1/4 inch in diameter.
- Loppers: Used for limbs up to 1.5 inches in diameter.
- Hedge shears: Used to shear formal hedges.
- Saws: Used to cut branches too large to prune with loppers.
- Pole saw and pruner: Used to prune difficult to reach branches.
Complete any heavy pruning in early to mid-summer and your bushes and trees will have the desired shape and size for next season. These chores have to be completed by mid-October at the latest. Any later and the plants could be susceptible to damage from cold weather if they have not had adequate time to regrow and harden before winter winds begin to blow.
So let the pruning begin!
Eileen and Peter Ward have owned a landscape and lawn maintenance company for 35 years. Eileen can be reached at Gswdmarco@comcast.net or 239-394-1413.