Just a couple of important steps when planting an evergreen are critical to the health and longevity of your evergreen conifer.
The Best Time to Plant an Evergreen
Evergreens can be planted just about any time that suits you, but some times are better than others. The absolute best time to plant an evergreen conifer is very early spring when the soil has thawed and the frost is out. Evergreens will enjoy getting established in cool weather with lots of spring rain. Planting evergreens can continue late into spring as long as you make sure they get plenty of water.
Early fall is also an excellent time to plant evergreen conifers, allowing a minimum of 6 or 8 weeks before the soil starts to freeze. The evergreen will have autumn and early spring to become well established before enduring the heat of summer, which is harder on the plant than winter is. Be sure to water deeply every week until the ground freezes, and mulch heavily to prevent heaving during freeze/thaw cycles.
During the heat of summer even an established evergreen often become stressed. A newly planted evergreen will already be experiencing transplant shock and working very hard to establish roots, so heat and drought will make it more difficult for the plant to remain healthy and strong.
Prepare the Planting Hole for Your Evergreen
Preparing the planting hole is your first task. Dig the hole as deep and wide as possible to loosen the soil adequately for the roots to extend easily. Evergreens are generally shallow rooted so at minimum dig 2 to 4 times the width of the root ball and at least a foot deep, several inches deeper than the root ball.
If you have selected an evergreen that grows well in your local region and your soil type you should not have to amend or enrich the soil. If you dig a nice hole and fill it up with beautiful rich soil, the roots will often find it difficult to transition from the hole to push through the native soil. When a good storm comes along you may be surprised to see the evergreen on the ground with a perfect clump of rich soil pulled right up with the roots. With that said, if your soil is extremely poor or not appropriate for the tree, you will probably have to do something to amend your soil. Your hole should be much much bigger to allow lots of space for the roots to spread and use as little amendments as possible to improve the soil. Evergreens should have well drained but moisture holding soil. A bucket full or two of compost mixed well into the soil will help the soil to retain moisture if your soil is sandy. A similar quantity of shredded leaves or peat moss will help the soil drain if your soil is heavy clay. Even evergreens are pretty adaptable, so don’t make them too comfortable in a rich hole, just a little improvement goes a long way to helping the tree adjust to your conditions. An certainly don’t make the hole so rich with amendments that water will not drain from the hole into surrounding soil.
Planting the Evergreen
Once the hole is prepared, check the depth of the hole by placing the container in the hole. Adjust and lightly tamp the soil level so that the top of the root ball is level with the surrounding soil level. Return the soil you dug out to the hole, smoothing and lightly firming the soil. Water the soil until it is well soaked. You may find that the root ball has slightly lowered as the soil settles. Grasp the trunk base and pull upward gently until the root ball is again level with the soil surface. Continue watering, filling, and adjusting the root ball level until the soil has settled evenly. Do not allow the root ball to settle and fill with soil up the trunk. If the evergreen is planted too deep it may cause the early demise of the tree.
Mulch in a 2 to 4 inch thick layer of mulch several inches wider than the widest part of the plant. Do not contact the trunk with the mulch, leave an inch or two gap to the trunk. The best mulches for evergreens are wood or bark mulch, rough trimmings or rough compost. The mulch is very important to help keep the roots moist and becomes even more important heading into winter. An evergreen will take up water from the soil all winter if it is available to prevent winter desiccation. The mulch will help the soil hold moisture and help prevent deep freezing of the soil.
- Poorly drained soil, planting too deeply and winter drying are the most common causes of damage or death of needled evergreens. They can be killed easily by water standing at their roots. They must be planted in well-drained soil.
- In the coldest climates make sure the root ball is planted at or even ever so slightly below the surrounding soil level and mulch heavily. This will help insulate the roots in winter and help to prevent heaving in freeze thaw periods. It is critical that your soil be well drained if you plant a little deep.
- The heaviest of sticky clay soils will need a large hole well amended with soil conditions to improve the drainage. In warmer regions with heavy clay the root ball may be planted about an inch above the surrounding soil level to avoid the problems of poor drainage.
Care of Newly Planted Evergreens
Simply ensure enough water to encourage good root development. Slow soak the evergreen each week by moving a slow trickling hose around the perimeter of the root ball over a period of several hours. The aim is to soak the root ball as well as a generous area surrounding the planting hole to encourage roots to move beyond the hole.
A newly planted evergreen may go through transplant shock. The foliage may yellow and needles may drop. Don’t worry about this in the first month or two, it is a natural response as it tries to establish itself. Do not over water and do not fertilize, you will only make it worse. Allow the plant to adapt itself to the new conditions for the first season.
Fertilizer is generally unnecessary even for mature, established evergreens. Never mix fertilizer into your planting hole to prevent root damage. Most conifers require no fertilizer at all. Evergreens that become stressed by winter dessication, very poor soil, disease, or insect damage may benefit from a light feeding in spring. Certain varieties may prefer a light feeding in spring after taking the first couple of seasons to establish. Follow the instructions for individual species cultivars, but generally a light sprinkling of a balanced granular fertilizer in early spring is plenty. Fertilizers formulated for evergreens will also improve soil acidity which helps to keep the needles green. Follow fertilizer package instructions carefully for application.
Winter die back in cold climates is quite common, particularly with newly planted evergreens that have not become well established yet. You can wrap your young evergreen with burlap or erect a sun/wind screen to protect it in the first year or two.
The next article has some great planting tips for special situations.