There’s nothing like a couple of years of drought to get us wondering just what kind of evergreens we can plant in the Wichita area.
Blue spruces have fried in the past couple of years; pines have been hit by disease.
But this is the prairie, after all. Kansas is the only state in the Lower 48 that doesn’t have a native pine tree. We’re not the icy-cold tundra of the Upper Midwest, where native pines can take the cold winters, and we’re not the desert Southwest, where native pines can take the hot wind.
“We’re both,” said Jason Griffin, director of K-State’s John C. Pair Horticulture Center in Haysville.
Most evergreen trees can’t take both weather extremes. Nor can they take both flood and drought. But there are a few that are reliable, and several that are mostly reliable. And we need them, says community forester Tim McDonnell. Evergreens provide year-round texture and color in a home landscape, and an invaluable service as a windbreak in an exposed landscape.
Griffin is doing probably the best work in the Great Plains on conifers and pine wilt – a devastating disease that has wiped out many of our pines – McDonnell says. Griffin is looking at ways to disrupt pine wilt, but assuming it’s here to stay, he’s also looking at alternatives to the pines that get pine wilt.
The experts don’t agree 100 percent on which evergreens to plant and which to avoid. People have different experiences with evergreens depending on where in the yard the trees are planted and what protection they have, the soil they’re planted in, and how they are watered. For example, when Griffin hears from people about Black Hills spruces – which have been touted as a good alternative to blue spruces – half of the reports are that the trees died, and half are that they’re doing fine.
People also have varying expectations when they plant a tree. Some don’t mind if their evergreens live only 10 years. McDonnell still enjoys having globosa blue spruces, even though he lost a couple last year to the sheer heat. “They lived 20 years,” he said.
And while people are looking for drought-tolerant trees now, it was only just a few years ago that 30-year-old pinon pines died when we had a very rainy summer.
With all of that in mind, here are some evergreens and conifers that are the best bets for our climate. The list should expand as the conifers that Griffin is testing have some more years – and weather conditions – under their belt. Atlantic white cedar and Nordmann fir are among those showing promise. As with other aspects of the landscape, our expectations need to change with evergreens. Think not thick Christmas tree, but something more airy and a tad more scrubby.
• Arizona cypress such as Blue Ice and Blue Pyramid (water it and then walk away, McDonnell said; they can’t take an irrigated site).
• California incense cedar (also to be kept on the dry side).
• Cedar of Lebanon, a true cedar; extremely heat tolerant but slower-growing than most people would prefer, Griffin says. Keep it on the dry side, McDonnell says.
• Oriental arborvitae (it’s what you see still alive in old cemeteries; too few nurseries are growing it now, McDonnell says).
• Loblolly pine. It often yellows with winter burn but pulls out of it. It’s fast-growing with a flush of growth in the spring and another flush later in the year. It tends to lose foliage near the base as it shades itself out.
• Lacebark pine (so far; it’s unknown whether it is susceptible to pine wilt).
• Atlas cedar, which includes but is not limited to the blue, weeping variety; there are green ones, too.
• Black Hills spruce (may need a bit of protection).
• Eastern red cedar (any Juniperus virginiana) such as the Canaert and Taylor.
• Ponderosa pine. Pine tip moth can make it a little ugly when it’s young but it outgrows it.
• Vanderwolf’s Pyramid limber pine.
• Bald cypress (not evergreen in winter but gives the effect in summer).
• Southern magnolia (not a conifer but keeps its green leaves in winter).
• Green Giant arborvitae. It grows so fast that it can become pot-bound, so be sure to inspect the root system when you buy one in a container.
• Southwestern white pine. A better alternative to Austrian pine, which gets tip blight.
• Deodar cedar. Not quite as cold hardy as cedars listed above.
A little riskier
If people are a little more horticulturally minded, they can try:
• Japanese cedar.
• American and Foster’s holly (not moisture-tolerant).
Check your pines
If you’re wondering whether a conifer is alive or not, snap open some buds and see if they’re dead or pliable. If the buds are alive, “it’ll probably push on growth and be fine,” Griffin said. Most pines are candling now – that is, putting out growth tips. If you have a pine that hasn’t started that process, it’s not a good sign, Griffin said.
“Most conifers are notorious for showing drought symptoms by the time it’s too late and recovery is not likely,” Griffin said.
Pines that died of pine wilt should be cut to the ground, leaving no stump, and then chipped, burned or buried. Do not save for firewood. Otherwise the pest that carries the disease will take flight and infect other pines.
Once evergreens grow up and fill in, they look nice. Don’t plant them close together to hurry the process; proper spacing ensures air flow and cuts down on disease.
The way you establish a tree will affect its drought tolerance, McDonnell says. If you overwater to start with, the tree won’t grow deep roots to go looking for water, and it will then require more water to stay alive. Know the requirements of an evergreen before you plant it.
For example, McDonnell is still using globosa blue spruces as ornamentals in the shade of other trees, making sure he doesn’t overwater them early in the season, but then making sure they get a little more water in the heat of the summer.
Except for trees that are most drought-tolerant, “water is your best fungicide and pesticide in a drought. Don’t fertilize in a drought” to put more growth on, McDonnell says.
You also may want to plant some ornamental evergreens even if they don’t make the most-reliable list. Giving them protection will go a long way to ensuring their success. Spruces should be protected from hot winds, but if you give them too much shade they becomes leggy. The east side is best for needled evergreens, where they can get a generous amount of morning sun but be out of the hot sun from noon to 6 p.m. Note the shade patterns in your yard in that time frame. A specialty plant that needs protection can be planted in the shade of another tree. A northwest corner can get brutal afternoon sun, McDonnell pointed out. Put your favorite plants on the east side of the house to protect them from the afternoon sun.