Timely Tips for the Backyard Gardener
January 27, 2012
A weekly publication for Backyard Gardeners by
Ohio State University Extension
PDF Timely Tips for the Backyard Gardener January 27, 2012
Fluctuating Temperatures and Its Affect on Woody Plants and Perennials- Troy Cooper, Extension Educator, Knox County
Woody trees and shrubs (both fruit and landscape) and many herbaceous perennials are very capable of tolerating very low temperatures if they are allowed to harden off and go dormant in the fall. Hardening off is triggered by the shorter days of late summer and fall, which cause the plant to stop growing. At this time, overwintering buds are matured. These buds are often covered by protective bud scales that protect the buds from water loss and physical damage.
These and other factors, such as excessive fall application of nitrogen, late fall pruning, excessive rainfall and temperature can all be factors in determining the dormancy level of these plants.
Hardiness is also affected by the return of warm temperatures in say….. January or…February. A few days of warm weather in mid or late winter can reduce plant cold hardiness significantly. Once cold hardiness is lost from mid or late winter warming, the plant cannot return to the same level of hardiness. If mild winter temperatures prevail, damage is unlikely. However, should severe temperatures occur, the tree will likely be damaged. Just the type of weather we’re seeing this winter!
So, if this is the case for trees this winter, what can be done? If fruit buds have been injured then the best option is to start making plans to buy fruit from somewhere else this season. The tree itself may just need a little extra care when it leafs out. Providing a shot of fertilizer earlier in the season will help it overcome the stress and help replenish depleted nutrient reserves.
Another type of winter root injury is caused by "frost heaving". The repeated freezing and thawing of the soil forces plants, especially smaller ones (strawberries, shrubs, young trees), to move upwards in the soil, sometimes pushing them out of the soil altogether. This can break many of the fine feeder roots. Injury or death usually follows if roots are broken or the shoots and exposed roots become dried out. Frost heaving is most common in heavy soils and is also affected by the soil moisture content.
Both frost heaving and freezing injury to the roots can be controlled in similar ways. Proper care during the growing season (irrigation, fertilization, and pest control) will promote healthier, hardier plants with deeper, more extensive root systems. Planting trees and shrubs at the proper depth and in well-drained soil will also prevent problems. Snow cover or an organic mulch, such as wood chips or sawdust, will help insulate the soil, preventing rapid fluctuations in temperature.
A Pruning Lesson for Beginners on Deciduous Shrubs. .. – Connie Smith, Program Coordinator, Fairfield County
With the warm and sunny days, we have experienced lately in the Central Ohio area, I’m just wondering how many gardeners have already had their hands on the pruners in 2012!! How can you not get out and enjoy 50 degree temperatures in January?
What are Deciduous Shrubs?
Deciduous shrubs are woody plants that drop their leaves in autumn. Examples of deciduous shrubs are lilac, forsythia, snowball viburnum, and cranberry cotoneaster. Deciduous shrubs are valued in the landscape for their foliage, branching characteristics, fall leaf color, flowers or colored twigs in winter. Some shrubs have colorful fruit that attracts birds. Selection of deciduous shrubs should be based on their function in the landscape. Shrubs have different habits of growth, fast, medium or slow, with upright, wide-spreading, arching or horizontal branching. The proper selection of the right plant for height and spread at maturity can reduce the need for pruning.
Why Prune?
Before you start to prune, know what you wish to accomplish. Pruning is one of the essential but least understood of the garden maintenance practices. Good pruning is the selective removal of branches without changing the plant's natural appearance or habit of growth. Shrubs trimmed to an artificial size or shape requires more pruning than shrubs pruned to keep their natural shape. Prune to improve the health of the shrub by cutting out dead, diseased, broken and overgrown branches that interfere with new growth. Prune to control the shrub's size, shape, flower, fruit and colored twig effect.
How to Prune:
Three methods used to prune a shrub for a specific purpose are thinning-out, renewal or rejuvenation and heading back or shearing. By thinning out, a branch or twig is cut off at its point of origin from the parent stem, to a lateral side branch, to a "Y" of a branch junction or at the ground level. This method of pruning results in a more open plant and does not stimulate excessive new growth. Considerable growth can be cut off without changing the plant's natural appearance or habit of growth. Plants can be maintained at a given height and spread for years by thinning out. This method of pruning is best done with hand pruning shears, not hedge shears. Thinning allows room for growth of side branches. Thin out the oldest and tallest stems first.
By renewal pruning, the oldest branches are gradually removed from an overgrown shrub at the ground level. It is best to do this over a three-year or longer period, leaving the younger more vigorous branches. New shoots that develop can be cut back to various lengths by the thinning method to develop into strong branches.
Heading back or shearing refers to cutting back a branch anywhere along the length of a stem. The cut may be above a bud, below a bud, or it may even leave a stub. The effect of heading back or shearing is to concentrate vigorous upright new growth below the cut. This method of pruning is frequently done with hedge shears without regard for the natural form or branching of the plants. If every branch or twig is headed back, more growth develops than was removed by the pruning. The natural form of the plant is altered by the extra growth. Hedges are pruned to a definite size or shape with hedge shears.
Avoid leaving stubs when pruning even a small shoot or twig. Short stubs will not heal over properly and will eventually provide a source of entry for insects and diseases. Cuts too far above a bud may destroy the bud by decay or die-back. Cuts too close to the bud may dry out the bud, especially in winter. The proper pruning cut should be 1/8 to 3/8 of an inch above the bud, slightly slanted away from the bud.
When to Prune:
The ideal time to prune most plants is during the dormant season prior to the start of new growth. Flowering shrubs may be an exception. Shrubs that bloom in spring may be pruned after flowering. Late flowering shrubs that bloom on wood produced the same year can be pruned before growth starts in the spring.
Some landscape horticulturists believe the effect of the shrub's structural branching characteristics is more important than its flowering effect in the total landscape design. Therefore, it may be better to prune all flowering shrubs in early spring before new growth starts. Some bloom will be sacrificed by this method. Either method can be recommended. One has to determine for himself the time to prune deciduous shrubs.
Pruning Tools:
· Pruning shears -- for branches 1/2 to 3/4 inches in diameter. Twisting shears to cut larger branches will strain and weaken them. The anvil-type of pruning shears is satisfactory for general pruning. However, the scissors or draw-cut type hand shear is preferred for close-cut precision pruning.
· Lopping shears -- have long handles and are designed to cut larger branches 3/4 to 2 inches in diameter.
· Pruning saws -- have narrow blades, coarse teeth and are designed to cut on the pull stroke. Small curved pruning saws are useful to prune larger shrubs.
· Hedge shears -- are used for shearing hedges or formal-shaped plants. Avoid using hedge shears for other pruning purposes.
