Cheyenne Garden Gossip

Gardening on the high plains of southeastern Wyoming


Winter damages evergreens

Pine branch

If the buds on the ends of pine branches are undamaged, new growth will help camouflage dead needles until they fall off. Photo by Barb Gorges.

Published May 4, 2015, in the Wyoming Tribune Eagle, “Evergreens looking dull? If this winter has caused your pines to brown, don’t cut them down just yet.”

By Barb Gorges

Don’t touch those red needles just yet, cautions Lisa Olson, director of Cheyenne’s Urban Forestry Department.

Wait until June to see if your pines and junipers get new growth before deciding what to do, she adds.

This past winter, property owners noticed that the needles on the tips of pine and juniper branches turned reddish brown. The color indicates the needles (juniper leaves are technically called scales), are dead.

Cheyenne had warm weather later in the fall than usual, preventing some evergreens from getting the cues that they usually get from cooler temperatures to go into winter dormancy. When the temperatures suddenly dropped in November, the fresh growth froze and died.

junipers

Most upright junipers (background) were not affected by the sudden freeze last November the way Pfitzer juniper shrubs (foreground) were. Photo by Barb Gorges.

While pines and junipers were most likely to be damaged, exactly which ones were hit hardest seems to have been hit or miss. Upright junipers seem to have no damage while the spreading Pfitzer juniper shrubs were most often hit.

But the amount of damage seems not to be so much a factor of how exposed the shrubs were to cold wind as perhaps variety.

In one Cheyenne neighborhood there is a sheared hedge of Pfitzers made up of five individual shrubs. One is totally green, the next three are totally red, and the one on the other end is green with red tips.

A property owner’s first urge is to cut off the dead stuff. However, this would add insult to injury for pines.

The bud for new growth is at the tip of the branch. A bundle of new needles grows from it in what is referred to as “candling.” That’s because it makes the tree look like it has hundreds of pale green candles before the bundles open up.

Pine trees keep their needles for three to five years before shedding them, Olson said. So if you are patient, the new needles will “overgrow” the dead ones, which will eventually fall off.

There is no need to prune unless you have branches that need pruning for other reasons.

If a pine does not candle all over, it may not have enough new green growth to photosynthesize, to make new buds next fall. A year from now is when those results will show up.

Sheared junipers

Different varieties of sheared Pfitzer junipers, even in the same hedge, have had different reactions to the sudden drop in temperature back in November. Photo by Barb Gorges.

Junipers grow differently than pines. Buds aren’t just at the tips of branches, and if their buds weren’t killed by the cold, they also might be able to “overgrow” the dead needles with new growth.

The Pfitzers allowed to grow naturally have dead needles only on the tips of their branches—the newest growth from last year. Older needles are still green. So what happens to Pfitzers that have been sheared into tidy shapes? Many seem to be completely red. We’ll just have to wait and see if they survive.

But Olson says this might be a good year to consider replacing overgrown Pfitzers.

They are often used as foundation plantings but after a number of years they can grow 10 or 15 feet high and into odd shapes as their branches become deformed by the weight of heavy snow.

If you have one of these, you might consider not waiting to remove it and plant something fresh.

But otherwise, wait until June to see what grows before deciding what to prune.

“It’s amazing how trees can come back,” Olson said.

Personal communication from University of Wyoming botany professor emeritus Dennis Knight explains what happened in November in more detail:

“It’s quite a feat for any outdoor plant to tolerate everything that’s thrown at it, and often they don’t survive if one day it’s warm and the next day unusually cold.  If the transition extends over a few days, the plants become “hardened,” which means that the cells produce more sugar and that lowers the freezing point.

“Over the years in Wyoming, our native and ornamental plants have been selected in one way or another to have pretty short hardening periods, but mortality will occur.  The whole plant may not be killed, but if too many of the leaves and buds turn brown, the chances of survival are slim. The plant may look completely brown, but if the buds on the twigs or at the soil surface have not been frozen, there’s a good chance the plant will survive.  Learning from experience, horticulturalists tell us which plants are most likely to survive in our state and which ones are not.

“You mentioned the brown juniper leaves.  Keep in mind that most evergreen plants, like the conifers and junipers, will still have some brown leaves, usually most noticeable in the winter and spring.  The plants as a whole normally live much longer than individual leaves. “Evergreenness” is bestowed on some plants because they always have leaves that normally last at least one year before they fall off, and not all of the leaves fall off at the same time.

“Plants with mostly brown leaves after an abrupt freeze may appear a little thin during the following year, depending on how many of the buds were deactivated.  I hesitate to call them “killed” because the plant could be still very much alive.  Such plants produce new leaves using energy stored in the twigs and roots.”

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Give your garden winter interest

Boy in backyard

I’m not sure what our son Bryan had in mind when he ventured forth with his toy shovel–digging to plant something, or digging to escape?

Published Dec. 21, 2014, in the Wyoming Tribune Eagle, “Give your garden winter interest.”

By Barb Gorges

“Winter interest” is a term you can Google. You’ll get sites wanting to sell you plants that flower in winter—in Zone 10, in Florida. Or maybe you’ll find Minnesota garden columnist Evelyn Hadden’s viewpoint that winter interest is anything that pokes up through the snow.

Cheyenne isn’t the tropics or the snow-covered north. Though we have at least seven months between the first hard frost of fall and the last in spring, we can be snow-free much of the time.

Winter interest is about the view from your window, rather than the summer experience of being in the garden. It’s about enjoying more subtle textures, such as different kinds of bark; and shapes. It’s about the sculptural qualities of branches. It’s about color, of which there is more than you might think.

Although our house was already 25 years old when we moved in, the winter view of the backyard was bleak: a flat lawn, clothesline poles, two big tree trunks, and all walled in by pink concrete block. Sending the kids out to play reminded me of sending them into a prison yard. It’s improved now with various plantings, but maybe it could be more interesting.

Spruce shrub

The spruce hedge at the entrance to the Cheyenne Botanic Gardens tapers towards the top so lower branches won’t be shaded and die. In the background is the columnar-shaped Woodward Juniper. Photo by Barb Gorges.

In early December, on what he calls a 50-50 day, 50 degree temperature and 50 mph wind, Shane Smith, Cheyenne Botanic Gardens director, and I discussed winter interest and took a tour of the gardens looking for it.

Conifers

The backbone of any Cheyenne garden is the evergreens, providing a backdrop and wind protection. At the entrance to the gardens’ greenhouse, a thick blue spruce hedge about 8 feet high blocks the view of the parking lot.

It started as a row of young, normal spruce trees planted 3 to 4 feet apart, but it’s pruned every year, forming an impenetrable wall. It’s important, Shane pointed out, that the hedge taper, becoming narrower towards the top. Otherwise, the lower branches are shaded, don’t get enough sun and die off.

Besides the typical Christmas-tree shapes, we saw a weeping variety of spruce, developed from trees that are naturally prostrate but can be trained to reach a certain height before cascading.

Junipers perform several functions. Low-growing varieties become ground covers, but Shane said to skip the really low kinds, only 6 inches tall, because they allow weeds to grow up through them.

Another, the Woodward juniper, developed at the old Cheyenne horticulture station, grows tall and narrow, providing a columnar shape that doesn’t take up much ground, and it’s a brighter green than some of the other, shrubbier junipers.

Rabbitbrush

Rabbitbrush is a native adapted to Wyoming’s dry climate. More moisture than regular rainfall will kill it.

One of our native shrubs can provide dried flowers. Rabbitbrush blooms yellow in the fall and the feathery,

pale-colored seed heads persist. The leaves are evergreen. Different varieties can range from a yellow green to a silvery color. You can also check out sagebrush, the epitome of Wyoming’s open spaces, which has silvery leaves year round, plus that quintessential Western smell when you brush against it.

However, both of these natives need to be planted where they won’t be irrigated. More moisture than our natural precipitation can actually kill them.

Deciduous trees and shrubs

It’s easy to think bare branches will be just black silhouettes. But with our abundant, sunny winter days, there is more to see, from gnarly cottonwood to smooth redtwig dogwood. Shane said to keep in mind that for dogwood and other shrubs with colorful bark, only the younger wood will show much color, so it is important to prune part back, close to ground level, every few years to encourage new growth.

Maybe you can choose trees and shrubs with fruit, red rosehips on rose bushes, orange berries on mountain ash, crab apples that cling after the leaves fall away—though how long they last will depend on how hungry the squirrels and birds are.

Karl Foerster grass

“Karl Foerster” is an ornamental type of reed grass. There are several varieties. This one grows 2 feet tall. Photo by Barb Gorges.

Other plants Shane recommended, some of which are growing at the gardens, are ephedra, with its weird bunches of long, match-stick-like twigs; mahonia, which reminds one of holly; mountain mahogany and various hawthorne trees.

Grasses

Ornamental grasses have become part of the professionally designed landscape, including the entrance to the Laramie County Library and many local businesses.

They dry to a nice tawny brown. Unlike other, stronger vegetation, they require only the lightest of breezes to accent the view with motion.

One kind Shane pointed out at the gardens is a variety of Karl Foerster grass growing in a 2-foot tall clump with feathery seed heads.

Another, blue oat grass, resembles a fountain of thin, bluish-green and silver strands which looks good as a lone specimen or as a herd of small, shaggy beasts. Shane said if you have a protected, south-facing exposure, there are other grasses you might try.

 

Blue oat grass

Blue oat grass has a fountain-like look. This specimen measures about 2 feet across. Photo by Barb Gorges.

If, at some point, the grasses are smashed by snow or it’s closing in on spring green-up, it’s time to cut back the tall grasses. Rather than clipping them, Shane simply grabs a bunch and saws through near the base with a small, folding pruning saw.

Perennials and annuals

Vegetable gardens are rather hopeless looking in winter. A good gardener cleans out all that stuff that turns slimy with the first frost. But maybe you left the sunflowers for the birds.

Some perennial herbs have winter color: silvery-looking sage (the cooking kind) and purple-y oregano. And some even stay green.

In the perennial flower bed there are lots of plants that don’t need to be cut back right away. Black-eyed susans, yarrow, and asters have interesting dry flower heads. In my garden, hollyhocks and mullein have big stalks that attract downy woodpeckers.

At the gardens, Shane and I found a clump of golden stalks with dried purple flowers, some kind of ornamental onion. And there was a sedum that had dried nicely.

But there will come a time when some of these dried points of interest break down and you will want to remove them.

Bulbs

Next fall, before heavy frost, get some of those early spring bulbs planted, even if it is just a handful here and there. Finding a crocus in March makes two more months of snow potential much easier to bear.

Ground cover

We still have bluegrass lawn at our house. Where the wind doesn’t blow off the occasional snowfall right away, it gets moisture and looks quite presentable. Native grasses look nice too.

Vinca, a vining ground cover, stays green, as do the leaves of some other low-growing perennials.

Use organic materials as mulch to cover bare spots around trees or in gardens. It’s good for the soil as it decomposes, and it can be interesting to look at, whether it is dried leaves or bark, natural or dyed color. Shane likes the look of pine needle mulch. He’s found if it’s ground up a bit, it doesn’t blow away.

Garden embellishments

Nothing says calendar page photo like snow gathering on a garden bench, wagon wheel or split rail fence. My favorite embellishment is a bird feeder or two, attracting bird color and movement and, even through window glass, cheerful bird sounds.

Junipers

Three varieties of juniper contrast with each other in color as well as growth habit: shrubby, ground cover and upright. Photo by Barb Gorges.

Resources

Go to the Cheyenne Botanic Gardens’ website, www.botanic.org, to the Gardening Tips section, where you will find lists of plants that grow well here.


Know your Cheyenne trees

Tree Walk sign

Look for this sign by the Beach House at Lions Park. Below it is a map of Cheyenne’s Tree Walk. Photo by Barb Gorges

Published July 20, 2014, in the Wyoming Tribune Eagle, “Know your Cheyenne trees.”

By Barb Gorges

Summer is a good time to appreciate Cheyenne’s trees. Each one is a bit of a miracle since most trees are not native to the High Plains except for cottonwoods along creeks.

In addition to enjoying their shade, you may want to study our landscape trees if you are thinking about planting one yourself. For up-to-date planting considerations and methods, see my recent WTE column archived at www.CheyenneGardenGossip.wordpress.com.

One way to find trees that grow well here is to follow the Tree Walk in the southwest corner of Lions Park, set up by the Cheyenne Urban Forestry Division. There is a map on a sign next to the beach house. You can also pick up a booklet with a map and tree descriptions at the nearby Forestry office located at West 8th and Carey avenues.

A few not so hardy trees are missing. Plus, since the horrendous hail storms in June and July, some trees may be a bit ragged.

The Tree Walk features 31 trees marked with sign posts. I’ll highlight 12 here, many illustrated with photos of 50-year-old trees from my own neighborhood so you can see them in proportion to the houses.

As you travel around Cheyenne admiring our trees, see how many more species you can find. If you need identification help and the Forestry office is closed, try http://www.arborday.org/trees/whattree/fullonline.cfm.

Tree traits

For more information on each species, check the library, or online at a site like Wikipedia, or see the University of Wyoming Extension’s “Landscaping: Recommended Trees for Wyoming,” http://www.wyoextension.org/agpubs/pubs/B1090.pdf.

On the Cheyenne Botanic Gardens website, www.botanic.org, under “Gardening Tips,” you can find a list of water-wise trees and shrubs that thrive with less water—too much can actually kill them.

First, learn these codes

Here are codes for describing my top-12 trees everyone in Cheyenne should be able to identify.

E–Evergreen tree. All types provide winter protection for birds

F–Fall color, loses leaves

H–Hail hardy

N–Native to the West

W—Wildlife likes the fruits

WW–Water-wise

 

Ponderosa and Pinyon

1. Ponderosa Pine (L) and 2. Pinyon Pine (R) Photos by Barb Gorges

1. Ponderosa Pine

E, H, N, W, WW

Surrounding the Forestry office is a grove of extremely tall, skinny examples. However, in my neighborhood, single specimens look nice and full. I.D.: Look for bundles of two or three needles 5 inches or longer.

2. Pinyon Pine

E, H, N, W, WW

Iconic, drought-tolerant trees of the Southwest, they’re short, even after 50 years. If you are lucky, they could produce the prized pinyon pine nut. I.D.: needles 1.5 – 2.5 inches in bundles of two.

Bristlecone & Spruce

3. Bristlecone Pine (L) and 4. Colorado Spruce (R) Photos by Barb Gorges

 3. Bristlecone Pine

E, H, N, W, WW

They grow very slowly but live a long time—one in California is more than 5,000 years old. I.D.: drooping branches full of needles look like bottle brushes.

4. Colorado Spruce

E, H, N, W

Growing several stories high, spruces can grow too wide, forcing homeowners to prune away their skirts. There are new varieties that are narrower. I.D.: needles are single, short, stiff and very prickly.

 

Fir and Juniper

5. White Fir (L) and 6. Juniper (R) Photos by Barb Gorges

5. White Fir

E, H, N, W

It looks like, and grows as tall as a spruce, but it’s a soft version. Another soft-needled, spruce-like tree is the Douglas-fir. I.D.: flat, short, single, flexible, soft needles.

6. Juniper

E, H, N, W, WW

There are many varieties of upright junipers available through nurseries. They all produce little waxy bluish berries. Birds also appreciate their windproof foliage. I.D.: no needles—just green scales.

 

Cottonwood & Oak

7. Plains Cottonwood (L) and 8. Bur Oak (R) Photos by Barb Gorges

7. Plains Cottonwood

F, H, N

Wyoming’s state tree has tough, heart-shaped leaves. But cottonwoods require a lot of water, and after about 50-60 years, these huge trees start deteriorating, dropping limbs on hot summer days.

8. Bur Oak

F, W

We aren’t too far from this species’ native range. Slow growing, it may take a while to produce significant shade, but meanwhile, wildlife will enjoy the acorns. It was hard-hit by the hail, but will recover.

Mtn ash & Linden

9. European Mountain-ash (L) and 10. American Linden (R) Photos by Barb Gorges

9. European Mountain-Ash

F, H, W

Bunches of little white flowers in the spring will develop by midsummer into orange berries that are quickly devoured by birds. The small leaflets seem to avoid hail damage.

10. American Linden

F, W

The hail was hard on it, but this is a great shade tree. Plus it has fragrant flowers and produces bunches of little fruits. I.D.: leaves are heart-shaped, but not tough like cottonwood.

Honey Locust & Crab

11. Honey Locust (L) and 12. Flowering Crabapple (R) Photos by Barb Gorges

 11. Honey-locust

F, H, W

Look for the thornless type. Its small leaflets avoided some of the hail. May have 7-inch-long brown pods if it isn’t a fruitless variety.

12. Flowering Crabapple

F, W

These were hard to miss this spring, blooming profusely pink or white for weeks along Cheyenne streets and in parks and yards. They are popular with wildlife, which may eat the flowers as well as the fruit. I.D.: Oval leaves and small apples–always a few left on the ground.