Evergreens Serve Many Functions in the Landscape
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Evergreen trees serve many functions in the landscape, from screening unsightly views to providing year-round interest. Over the past few years evergreens in the Kansas City area have suffered from a number of aliments. The problem with evergreens is compounded by the fact that we do not have many choices. Evergreens are not native to the prairie region, so all potential choices are considered introduced species that must be able to tolerate our wide ranging, and seemingly ever-changing, climate.
Pines
Pines, for the most part, used to make up our evergreen forest in the area. That is, until needle diseases, nematodes and environmental conditions wreaked havoc. Because of these problems Extension does not recommend planting Austrian and Scotch pine. White pine is not tolerant of uneven moisture, poor soil conditions and other stresses.
Now that pine trees are not recommended what are our options? This is a commonly asked question. It does have an easy answer, but most people do not like their choices. The following is a listing of recommended evergreens for the area. Remember, when it comes to evergreen selection the best choice may not be what your favorite tree is, but picking the one that will thrive in the location and the care it will receive. The old saying, “right plant, right place” is the mantra for success with evergreens.
Junipers
Let’s just address this right up front; yes I agree, junipers do not have the classic look and feel of the desired evergreen. Remember though, it is all about right plant in the right place. Junipers are the closest to a native evergreen. With that in mind, this plant is better able than any other to withstand the harsh plain’s conditions. It suffers from very few serious insect and disease problems. Junipers are best able to withstand poor conditions, uneven moisture conditions and locations that will not be watered. The plant is tough as nails. Translated this means it is the go-to evergreen in many areas.
There are several upright tree forms that do have a nice habit and look in the landscape. These include ‘Canaerti,’ ‘Spartan,’ ‘Keteleeri’ and, for very narrow locations, ‘Taylor’. These cultivars are great for groupings to create screens and block the wind. Once established they can even thrive on very little or no supplemental irrigation. No other evergreen will be able to do that. So get over the fact that the cousins of these selections grow like weeds in the ditches. Junipers deserve more attention in the landscape, as they are the best all-around evergreen choice.
Arborvitae
Small arborvitaes have been planted around entrances and foundations of many homes for generations. A newer introduction is now recommended as a larger evergreen for the landscape. The recommended selection is ‘Green Giant’ arborvitae. ‘Green Giant’ is a fairly fast grower that has a very pyramidal growth habit. The foliage is a rich green in the summer that slightly yellows in the winter. Some report the tree to be deer resistant and free from bagworms. I would say the jury is still out on this claim.
‘Green Giant’ can reach a height of 30 feet and spread maybe 15 feet wide, helping to make it a good fit for many smaller landscapes. Do not confuse this species with the smaller ornamental arborvitae common on the market, ‘Emerald’ and ‘Degroot’s Spire’, as these are smaller and narrow selections that work best in landscape beds or as a small screen around the patio. ‘Green Giant’ has fair drought tolerances but did suffer in the summer of 2012. Supplement moisture would be needed to keep the plant healthy during more severe conditions.
Spruce
The poster child for beautiful evergreens would be a spruce of some type, whether one of the green foliage types or the Colorado blue spruce. The problem with spruce is that it is not totally adapted to our climates. The same weather patterns that can kill a pine can also take out a spruce.
Spruce, as a rule of thumb, prefers to grow in soils that have even moisture. Spruce will not tolerate even a slight drought. Site selection and proper maintenance is the key to good spruce growth. That means that spruces should only be planted in well-drained soil locations and in areas that can be watered. This also implies that you will water the tree, even with a mild drought. This watering is for the entire life of the tree, not just the first few years of establishment.
There are a number of spruces that can be planted in our area. The most popular is the Colorado blue spruce. My recommendation would be to plant Norway spruce species over the blue spruce. Drive around old neighborhoods and you will see more mature Norway spruce. That tells me they are more adaptable.
Spruces are best used as landscape trees, either as a specimen or a screen. Situating them in the landscape should make watering easier. Spruce should be planted with caution in open areas, as the heat and drought could cause problems.
There are other species of evergreens on the market, but for the most part these should only be planted as specimen trees and provided with all the tender loving care they need to thrive.
Which evergreen tree to plant should be carefully considered. It is not a snap decision, but one that should be made based only on location, long-term maintenance and the function of the tree. Picking the most beautiful tree does not enter the equation for long-term success. That is unless you know what requirements it takes to make it a lasting addition to the landscape.
