In the winter, a garden can become rather desolate-the flowers have faded, their leaves have turned brown, and you almost wish for snow just to cover the soil and the bare branches of perennials. Between the long winter sleep that begins in October and lingers until the first tulip pokes its head up into the spring air, evergreens are a great solution. They are permanent elements that can provide structure for your garden-each and every season. Evergreens come in a range of sizes, shapes and colours and choosing the right plant for your situation is simple if you know a few basics.
When you visit a nursery, perhaps the most important consideration when buying a plant is its size at maturity. There are plenty of trees and bushes available that grow to 10 metres or taller. You may not be happy with a towering tree in the middle of your rose garden several years in the future so it is best to find out what the mature size of the plant will be before you buy.
Sometimes the word 'dwarf' is used to describe plants that grow slowly and other times it is used to describe plants that are much smaller than their wild cousins. For example, the Piceaabies "Nidiformis' reaches only one metre when fully grown which is appreciably less than another member of its genus-the Norway Spruce.
Needles vs. Leaves
It may surprise you to learn that not all evergreens have needles. In fact, "evergreen" simply refers to a type of plant that does not experience significant die-off of foliage in the winter. Needled evergreens produce their seeds in cones and thus don't have to produce flowers or berries. Their narrow needles make them well adapted to survive in dry soil and windy winter climates. Broadleaf evergreens often have wide leaves and attractive flowers. They lose more moisture through their leaves than do needled evergreens and, for that reason, usually require moist soil and protection from harsh winter weather.
If you prefer needled evergreens the following are some favourites:
- Balsam fir Abies balsamea - the needle-bearing tree can grow to 23 metres but the dwarf version, 'Nana', grows slowly to approximately one metre.
- Savin juniper J. Sabina - the boughs of this evergreen arch out attractively to create low ground cover.
- Russian cypress Microbiota decussata - creates bright green ground cover to a height of only half a metre.
Some tried and true broadleaf evergreens include:
- Bearberry Arctostaphylos uva-ursi - grows to only 30 cm high and produces dense foliage that turns red in winter.
- Oregon grape holly Mahonia aquifolium - the dwarf version of this evergreen called 'Compacta' grows to 1 metre high and tolerates shade and acidic soil.
If you enjoy the look of shrubs that have been pruned into various shapes, and hope to try topiary in your garden, start with a plant that has dense foliage and is able to tolerate regular clipping. There are three main species recommended for topiary: Buxus sempervirens (box), Taxus baccata (yew) and Laurus nobilis (bay).
Evergreen does not mean everlasting. Bushes tend to have a shorter life span than trees-usually three to 30 years. Evergreens are also susceptible to drought, over-watering, insect infestations and soil problems.
Brown needles or leaves may indicate that the plant has been scorched and dehydrated. This often happens when the weather changes quickly from cold temperatures to bright sunshine. The sunshine and dry winds cause the foliage to lose moisture but the roots, which are still dormant, cannot deliver moisture from the soil. Spray the plant with water every few days and provide protection from the wind by planting bushes in clusters or near buildings. You may also wish to cove
Yellow leaves often indicate soil problems. Some evergreens such as Azalea and Camellia, can develop yellow leaves if the soil is too alkaline (too much lime or chalk has been added or is naturally present in the soil). Try adding peat moss or iron chelate to increase acidity. Yellow leaves can also develop if the plant has poor drainage. r your shrubs to protect them from wind and frost.
Creating the Best Results
Start with healthy plants. Look for plants that have most of their leaves or needles. Check the main branches for signs of heavy pruning, which may indicate disease. Try to pull off a needle or leaf-unhealthy plants tend to drop their foliage easily.
Space your plants. You can plant evergreens in clusters for artistic effect or to provide some protection from the wind but be careful not to plant them too close together. If air is not able to circulate freely in among the foliage, mold can flourish.
Prepare the ground. Dig a hole approximately one and a half times as wide and as deep as the root ball. If your soil contains a lot of clay, mix peat moss and compost into the soil. These additions will increase the organic material in the soil thus improving moisture retention and drainage. Replace some soil in the hole then water. Place the plant into position then fill in the gaps. Press the soil firmly. Water thoroughly.
Don't plant or transplant in the middle of the afternoon. Sunshine, especially in warm weather, causes a plant to release water through its foliage as part of photosynthesis. That moisture must be replaced by water that comes up through the roots from the soil. A newly transplanted shrub will have suffered some root shock and may not be able to deliver adequate moisture to the leaves or needles. The best time for transplanting is shortly before sunset.
With some care and the occasional watering, evergreens can be lasting and integral additions to your garden.