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Unseasonal weather can have an impact on some plants

Unseasonal warm weather was a welcome break from winter in Alberta. The weather will have little effect on hardy plants but might be detrimental for some of the tender ones. Transpiration rate of evergreens increases as the temperature increases. Roots of cedar and junipers that were not completely hydrated in the fall might not be able to replace the moisture lost from the needles and scales.
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Unseasonal warm weather was a welcome break from winter in Alberta.

The weather will have little effect on hardy plants but might be detrimental for some of the tender ones. Transpiration rate of evergreens increases as the temperature increases.

Roots of cedar and junipers that were not completely hydrated in the fall might not be able to replace the moisture lost from the needles and scales.

When the evergreens lose too much moisture, the needles and scales turn a dull shade of green, then brown. On warm days, water the soil around junipers and cedars. Some, but not all, the moisture will make it to the plant’s roots.

Another method is to apply a spray that slows down plant transpiration. The anti-transpiration spray is water soluble and to be effective must be reapplied each time the plant becomes wet. The spray is available at most garden centres.

Covering the plants in burlap does not change the air temperature but it does block the direct sunlight and the glare from the snow from reaching the plant, helping to slow down transpiration.

Melting snow can cause large icicles to form. If the icicles form on plants, the weight can cause the branches to bend or break.

It is best to remove the icicles as soon as they appear. Bent plants will slowly begin to move upwards once the weight is removed.

If they do not regain their original shape, use a wide strip of cloth or plastic to tie the branches back into proper position. Remove the binding once the plant regains its proper shape. Snow insulates the ground, protecting roots from extreme and fluctuating temperature. Once snow melts, the protection is lost. Tender plants can be safeguarded by placing mulch in the fall or by replacing melted snow with snow from other parts of the yard. Make sure that the snow used does not have chemicals used for melting snow from walks. Use the warm weather to walk around the yard, looking for rodent damage. Pack snow around new plantings to remove the possibility of mice and voles tunnelling under the snow to feast on tender bark. Deciduous trees and shrubs can be pruned at this time of year. Pruning is a relatively easy process if simple rules are followed.

The most common mistake in pruning is to leave a stub. Always cut back to another branch or bud. Any part of the branch that is left will die and eventually rot. The stub will look unattractive and has the potential to let insects and diseases into the plant. Cuts that are done correctly are smooth and heal.

Another mistake is to remove too much of the plant at one time.

When too much material is removed, the plant sends out a multitude of new branches in the form of water sprouts. Do not remove more that a quarter of a tree or shrub in any growing season.

Start by removing all dead wood. Then remove branches that are rubbing on another branch.

When given a choice, keep the strongest branch that is pointing in the correct direction. Lastly, shape the plant.

Prune to enhance the natural shape of the plant. Trying to keep a naturally tall tree as a shrub will require constant pruning as the plant will always revert to its natural shape. This is why short hedges often get trimmed two or three times a season. Spend time outside on warm days. There is always something to do in the garden.

Linda Tomlinson is a horticulturalist who lives near Rocky Mountain House. She can be reached at your_garden@hotmail.com.