Utah runs from USDA zone 4a to 9a, and that spread sorts hedge plants into three groups. Of twelve hedge species commonly planted, four survive the whole state, eight survive only in certain zones, and none fail everywhere. The trouble sits in those eight. A hedge that thrives in a warm southern yard can die in a high valley, and a favorite from the cold north can struggle in the south. Three of the twelve can never be cut back to size once they outgrow it.
What actually holds in Utah
The USDA zone rests on one number, the average annual extreme minimum temperature (USDA Plant Hardiness Zone Map 2023, built on 1991-2020 normals). A plant rated only to 6a can sit happily in a mild valley and die the first hard winter in a colder town a few counties over. For dates, the Salt Lake City reference station shows a last spring frost between April 12 and April 29 and a first fall frost between October 18 and October 29 (NOAA NCEI 1991-2020 Climate Normals, 30 to 70 percent freeze-probability band). Salt Lake sits in a mild valley, though. Most of Utah is higher and colder, and southern Utah is warmer, so check your own zone before you buy.
Which hedge plants fail in part of Utah?
Start with the cold end. Leyland cypress and cherry laurel are listed only from 6a up, and boxwood from 5a. In the coldest high-elevation yards, all three are a gamble. At the warm end, privet, yew, arborvitae and eastern hemlock are listed only through 7b, and arrowwood viburnum, boxwood and cherry laurel through 8b. Leyland alone reaches 9a. Those upper limits are often about summer heat as much as winter cold, so a plant at the edge of its range may survive without looking good.
| Hedge plant | Zones listed | Regrows from old wood? |
|---|---|---|
| Boxwood | 5a to 8b | Yes |
| Leyland cypress | 6a to 9a | No |
| Privet | 4a to 7b | Yes |
| Cherry laurel | 6a to 8b | Yes |
| Yew | 4a to 7b | Yes |
| Arborvitae | 4a to 7b | No |
| Eastern hemlock | 4a to 7b | Yes |
| Arrowwood viburnum | 4a to 8b | Yes |
Which hedge plants hold in every part of Utah?
Four make it from 4a through 9a: American hornbeam (6 to 15 feet as a hedge, about 12 inches of growth a year), inkberry holly (evergreen, 5 to 15 feet), winterberry holly (5 to 15 feet, loses its leaves in winter) and eastern red cedar (8 to 20 feet as a screen). “Holds” here means survives the cold, and the hollies and hornbeam still have opinions about soil, covered below. If you garden in the cold north of the state, Hedge Plants for Idaho: What Holds, and What Only Looks Hardy sorts many of the same species for similar winters.
The hedges you can never cut back down
Three of the twelve species will not sprout from bare old wood. Leyland cypress, arborvitae and eastern red cedar all grow their foliage on the outer shell. Cut into the brown interior and the branch stays bare for good. A shortened evergreen of this kind keeps a permanent hole where you cut. The height you plant for is the height you live with, and every cut has to stay within green growth.
Leyland is the one that catches people. It grows 3 to 4 feet a year and wants 15 to 25 feet as a screen, so a young plant clears a 6-foot fence within a couple of seasons. It is also listed only for zones 6a through 9a. A homeowner in a colder valley risks a fast hedge that dies, and a homeowner in a warm one risks a fast hedge that cannot be shortened. Prune it from late spring to midsummer and keep trimming small and regular.
Arborvitae (Thuja occidentalis) is slower, at 6 to 9 inches a year, and holds 4 to 15 feet as a hedge in zones 4a through 7b. Trim it in late winter before growth starts, or in midsummer. Eastern red cedar grows 12 to 24 inches a year and holds across all of Utah. It takes light cuts only, in late winter. Neither will forgive a hard cut-back, so both suit people who want a screen and will leave it alone.
The rest regrow from old wood. Boxwood, privet, cherry laurel, yew, arrowwood viburnum, hornbeam and both hollies can be cut hard if they outgrow the spot, and they fill back in. Eastern hemlock regrows too, but it takes light cuts only, so treat it gently anyway. If you may someday want to drop a hedge from 10 feet to 6, choose from this group.
Timing matters as much as the plant. Pruning windows for all twelve run from late winter through midsummer, with none in autumn. Boxwood, yew, cherry laurel and hemlock are done in late spring. Privet gets two trims, spring and midsummer. Arrowwood viburnum goes right after flowering. Hornbeam waits for midsummer, after the first flush, and the hollies are trimmed in late winter while dormant. Mid-October is for planting and watering, not shearing.
Matching the plant to the job
Pick the job first, then the plant. A hedge that needs constant fighting is the wrong species for the spot, however hardy it is. Four jobs cover most yards:
- Tall privacy screen: eastern red cedar (8 to 20 feet, all zones), arborvitae (4 to 15 feet, 4a to 7b), eastern hemlock (10 to 20 feet, 4a to 7b), or Leyland (15 to 25 feet, 6a to 9a, never cut back).
- Low, formal edge: boxwood (2 to 6 feet) or yew (3 to 8 feet), both clipped in late spring.
- Informal flowering hedge: arrowwood viburnum (6 to 10 feet, 12 to 24 inches a year), trimmed right after it flowers.
- Winter cover: inkberry holly stays evergreen. Winterberry holly drops its leaves, so it will not screen a window in January.
Growth rate decides how long you wait. Boxwood adds 3 to 6 inches a year, so closing a 2-foot gap takes four to eight years. Cherry laurel adds 1 to 2 feet and yew 6 to 12 inches. Hemlock, arrowwood viburnum and eastern red cedar each add 12 to 24 inches a year, and Leyland races ahead of them all. Fast growth is cheap at the nursery and costly later, since fast plants need the most trimming. Privet grows 2 to 3 feet a year and needs two trims a season to stay neat.
Gardeners comparing notes with wetter, colder states will find eastern species such as hemlock and red cedar sorted differently in Hedge Plants for New York: What Holds, and What Only Looks Hardy and Hedge Plants for Maine: What Holds, and What Only Looks Hardy. The broader Hedges section covers planting and trimming basics.
The ground you are planting into
USDA lists the Mivida series as representative of Utah. It is an Aridisol, a dry-climate soil that is usually alkaline and often carries salts. The surface layer averages a pH of about 8.1, with 72 percent sand, 9 percent clay and 19 percent silt. Organic matter is about 1.5 percent, and the ground drains well (USDA NRCS Soil Data Access, surface horizon of the major components of the series). That is the soil that stands for the state, not the soil in every yard. River bottoms, hillsides and any lot a builder scraped or filled can differ completely, and the pH is not necessarily yours.
This ground tends to shed water fast and hold little of it. A newly planted hedge on sandy, low-organic-matter soil dries out between waterings, so check the soil often and water before it dries. A layer of mulch over the root zone slows evaporation. Where soil is salty, salts can build up as water evaporates, so deep, less frequent watering is gentler on young roots than daily sprinkles.
Alkaline ground matters most for the plants that prefer acidic soil. Hollies, including the two on the hardy-everywhere list, generally do better in acidic ground and can yellow in alkaline soil. Survival is not the same as looking good. Hornbeam and eastern hemlock also like steady moisture, which sandy soil does not give them.
Test before you buy fifty plants. Utah State University Extension can point you to soil testing that gives your own pH and salt reading, and its county offices can confirm your zone. If you amend, work compost through the whole planting strip instead of filling individual holes, so roots do not circle in a pocket of rich soil.
Common questions
Can I plant Leyland cypress anywhere in Utah?
No. It is listed only for zones 6a through 9a, so colder valleys and high-elevation yards are outside its range. It also cannot be cut back to size, and it grows 3 to 4 feet a year. In a zone where it does hold, plant it only where it has room to reach 15 to 25 feet.
Which hedge can I cut back hard if it outgrows its spot?
Boxwood, privet, cherry laurel, yew, arrowwood viburnum, American hornbeam and both hollies regrow from old wood. Arborvitae, Leyland and eastern red cedar do not, so cut those only within green growth. Eastern hemlock regrows but takes light cuts.
Should I amend sandy, alkaline soil before planting a hedge?
Mixing compost through the planting strip helps sandy ground hold water. A soil test tells you the actual pH and salt level, which matters for hollies. Matching a plant to the ground you have usually beats trying to change it.
Is October a good time to prune a hedge?
No. The pruning windows for these species run from late winter to midsummer. Late fall cuts can leave fresh growth exposed to the first hard freeze, and at Salt Lake City, that comes between October 18 and October 29 in the 30 to 70 percent band. Mid-October suits planting and watering.