Techny Arborvitae: Minnesota's Privacy Workhorse (Spacing, Growth Rate, Care)

Plant Techny arborvitae 4 feet on center for a privacy screen in the Twin Cities — 13 plants for a 50-foot run. Techny grows about 1 foot per year here, not the 3 feet nursery marketing claims, so a #10 planting closes into a solid screen in roughly six to eight years and settles at 12 to 15 feet tall by 6 to 10 feet wide.

Techny is the arborvitae we sell and plant most, and it earns that for real reasons: it is hardy to zone 3, it holds dark green color through a Minnesota winter instead of bronzing out like some cultivars, it takes clay, and it makes a genuinely dense screen. It is also, like every Thuja occidentalis, the single most heavily browsed evergreen in the metro. Both of those things are true at once, and any guide that only tells you the first half is selling you something.

This is the full picture: what Techny actually is, how fast it really grows here, the spacing math for a hedge that closes, how to plant it in clay-loam, watering by year, pruning, winter care, the pest and browse problems, what a 50-foot run costs installed, and — the part most pages skip — the sites where we tell customers not to plant it at all.

What Techny arborvitae is

Techny arborvitae (Thuja occidentalis 'Techny') is a broad, dense, pyramidal selection of native northern white cedar, grown for dark green year-round foliage and used as a privacy screen and windbreak across the Upper Midwest. It is also sold as Mission arborvitae; the two names are the same plant. It originated as a seedling selection at Mission Gardens in Techny, Illinois, which is where the name comes from.

Compared with the other arborvitae we stock, Techny is the broad one. Emerald Green and Holmstrup are narrow and slow, American Pillar is narrow and fast, and DeGroot's Spire is a specimen rather than a hedge plant. Techny sits in the middle: wide enough to fill a screen with fewer plants, and dense enough that the screen is solid.

Growth rate: what one foot a year actually means

Nursery tags and big-box marketing routinely claim three feet of growth a year for arborvitae. In Twin Cities conditions that is fiction. Our field number for Techny is about one foot per year, and it is what we quote customers before they buy, because the gap between the marketing number and reality is where disappointed customers come from.

A few things make the real number lower. Our season is short, our clay stays cold late, and the first year after planting produces almost no top growth at all because the plant is rebuilding roots — a balled-and-burlapped tree loses most of its root system at the nursery.

The practical takeaway: if you need screening within two years, buy the height, do not wait for it. Stepping from #5 to #10 buys you roughly a foot and a half of instant height and about two years of waiting. If you can wait, the smaller stock establishes faster and catches up. Our full comparison across species is in how fast privacy trees actually grow in Minnesota.

Spacing: the math for a screen that actually closes

Spacing is the decision people get wrong most often, and it is not reversible. Too tight and you get a dense screen fast that shades out its own interior, holds moisture, and invites blight. Too wide and you have a row of individual trees with permanent gaps at the base.

Two field notes. Set the row at least 4 feet off a property line so the mature 6-to-10-foot width does not become your neighbor's problem. And do not stagger a double row unless you have 12 feet of bed depth — a staggered Techny row in a 6-foot strip is a blight incubator.

Planting Techny in Twin Cities clay

Timing. Our cutoff for planting evergreens in fall is mid-to-late September, around the 20th. Evergreens transpire all winter and need root contact with soil before freeze-up; planted in October they desiccate and fail. We plant deciduous stock through the end of October, but arborvitae is not deciduous. The fall window opens in late August, and September is the best planting month of the year. Spring runs late April through May.

The hole. Dig two to three times the width of the root ball and no deeper than the root ball itself. In clay, digging deep and backfilling loose soil creates a bathtub that fills with water. Set the top of the root ball an inch or two above surrounding grade so it drains, backfill with the native soil you removed rather than a rich amended mix, and firm it in with water rather than by stomping.

Drainage test. Before you plant a row, dig a 12-inch hole, fill it with water, let it drain, and fill it again. If the second fill is still standing 12 hours later, that spot will kill arborvitae. Raise the bed 6 to 8 inches or change the plant.

Mulch. Two to three inches of shredded hardwood over the root zone, pulled back a few inches from the trunk. Never mound mulch against the stem.

Watering, year by year

Our standing guidance is 5 gallons per plant, once a week, for the first two full summers. Not one summer — two. Rainfall counts toward the weekly total, and University of Minnesota Extension notes that a newly planted shrub in Minnesota needs at least two growing seasons to establish.

• Year 1. 5 gallons per plant per week, delivered slowly right at the base so it soaks the root ball rather than running into the lawn. Scale up for #15, #20, and balled-and-burlapped stock.
• Year 2. Same weekly soak. This is the year most people quit, and it is the year a lot of arborvitae dies.
• Year 3 and after. Only during prolonged drought.
• Every fall, forever. Water evergreens deeply through October until the ground freezes. This is the single most effective thing you can do to prevent winter burn.

Lawn irrigation does not count. A new root ball is dense nursery media sitting inside clay, and sprinklers wet the clay without ever saturating the ball. To check, probe six inches down at the edge of the root ball a day after watering.

Pruning and shaping

Techny does not need pruning to be a screen. It needs pruning if you want a formal, flat-faced hedge or if you want to hold it below its natural height.

• When. Late spring after the new growth flush, or midsummer. Avoid pruning after August — new growth that has not hardened off going into winter is exactly what burns.
• How much. Never cut back into bare brown wood. Arborvitae produces new growth only from living green foliage, so a cut past the green is a permanent hole. Shear lightly and often rather than hard and rarely.
• Shape. Keep the base slightly wider than the top so the lower branches get light. A hedge sheared narrower at the bottom loses its skirt.
• Topping. You can hold Techny at a height by cutting the leader, but it will thicken and need annual attention. If you need a plant that stays under 8 feet, buy a smaller cultivar instead of fighting this one.

Winter: burn, snow load, and fall prep

Winter burn is the most common complaint we get on arborvitae. UMN Extension describes the mechanism directly: winter sun and wind pull moisture from evergreen foliage while frozen soil prevents the roots from replacing it, and Extension specifically names arborvitae among the species hit hardest, with newly transplanted plants suffering most. Damage shows on the south, southwest, and windward sides and appears between snowmelt and Memorial Day.

Prevention: deep fall watering through October, and burlap screens on the south and west sides of exposed plantings for the first two or three winters. Skip tight plastic wraps — they trap heat against foliage and often make burn worse. If a plant does burn, wait until mid-spring bud swell before you cut; a lot of brown foliage has live buds behind it.

Snow and ice are the other winter issue. Techny carries multiple leaders, and heavy wet snow can splay or break the top. It is genuinely susceptible to stem breakage under ice and snow load, though a broken leader is usually taken over by another within a few seasons. Brush heavy snow off with upward sweeps, never downward and never with a shovel.

Pests and problems, starting with the browse

Rabbits and deer — the part most pages skip

This is where we differ from most sellers of arborvitae, and we would rather tell you now than replace the hedge later.

Rutgers Cooperative Extension's long-running "Landscape Plants Rated by Deer Resistance" places Thuja occidentalis in its worst category, Frequently Severely Damaged. The Minnesota DNR's woodland habitat guidance lists white cedar — the same species — among deer's preferred winter foods. Deer browse it to a clean line as high as they can reach, usually five or six feet.

Rabbits are worse, because their damage is permanent. They work from the packed snow surface upward, stripping foliage and bark from the lower two to three feet all winter. Since arborvitae cannot regenerate from bare wood, that bald skirt never fills back in, and a rabbit that chews a complete ring of bark around the trunk girdles and kills the plant outright.

If you plant Techny in a browse-prone yard, protection is an annual commitment. Extension's guidance for rabbits is hardware cloth cylinders set about six inches off the trunk and extending 18 to 24 inches above the anticipated snow line — above the snow line, not above the ground. For deer, a well-built 6 to 8 foot fence, plus repellents such as Bobbex, Plantskydd, Liquid Fence, or Deer-Out reapplied every four to six weeks from October through April.

If you are not going to do that every year, plant a columnar juniper screen instead. More on protecting what you already have is in rabbit-resistant plants for Minnesota yards.

Mites, blight, root rot, and salt

• Spruce spider mite. The most common insect issue we find. It is a cool-season mite that feeds in late spring and early fall and goes quiet in midsummer heat. Damage is fine yellow-to-bronze stippling across the whole plant with silk webbing. Confirm with the white-paper tap test before treating.
• Leaf blight and tip blight. Random tan-to-brown sections with tiny black fruiting bodies, worst on lower branches in rows planted too tight. Airflow is the fix.
• Root rot. In a low, wet spot in clay, root rot organisms take arborvitae out over a season or two. There is no spray for a drainage problem.
• De-icing salt. UMN Extension recommends keeping plantings at least 3 feet from drives and walks and 7 feet from roadways. Techny is a poor boulevard plant.

The full symptom-by-symptom walkthrough is in why is my arborvitae turning brown.

What a Techny screen costs installed

Twin Cities 2026 pricing, 50-foot run at 4 feet on center, 13 plants, including our per-plant installation fee. Plant delivery and planting carry no minimum job.

What moves those numbers: access, existing sod or bed prep, and distance from our Waconia nursery. Delivery is free on orders over $200 and runs two to four business days.

Where Techny fails — do not plant it here

• Anywhere with visible rabbit runs or regular deer traffic, unless you commit to hardware cloth and repellents every winter for the life of the hedge. Plant Taylor Juniper or Sky Rocket Juniper instead.
• Boulevards and driveway edges that get salted. Salt spray browns it out from the tips down within a season or two.
• Low, poorly drained spots. Arborvitae wants moisture with drainage, not wet feet. Standing water is fatal.
• Deep shade. Under about six hours of sun it thins out and never makes a real screen.
• Beds narrower than about 6 feet. A 6-to-10-foot mature width in a 4-foot strip means shearing forever. Use North Pole, Holmstrup, or a columnar juniper.
• Windswept west-facing lot lines with nothing upwind. Techny survives them but burns most winters. Black Hills Spruce or juniper is more durable.

Companion plants and design

A pure arborvitae wall is the most fragile screen you can build — one pest or one bad winter takes the whole thing at once. We plant mixed screens whenever there is room:

• Black Hills Spruce — slower at roughly 6 to 12 inches a year, but broad, browse-resistant, and salt-tolerant. Anchors the ends of a run or fills a corner.
• Taylor Juniper — narrow, browse-resistant, and a natural substitute wherever the arborvitae keeps getting chewed.
• Isanti Dogwood and Summer Wine Ninebark — deciduous shrubs in front to hide the base and add winter stem color.
• Karl Foerster Feather Reed Grass — vertical texture at the foot of the hedge that stands up through winter.

Frequently Asked Questions

How far apart should Techny arborvitae be planted? Four feet on center is our default for a privacy screen — 13 plants for a 50-foot run. Three feet closes faster, in about four to five years, but leaves the row permanently crowded. Five feet is healthier long term but shows gaps for eight to ten years. Wider than five feet and you have a row of trees, not a hedge.

How fast does Techny arborvitae grow in Minnesota? About one foot per year in Twin Cities conditions. The 3-feet-per-year figure on nursery marketing does not hold here — our season is short, the clay stays cold, and the first year after planting produces almost no top growth while the plant rebuilds roots. From #10 stock, expect a solid screen in roughly six to eight years.

How tall does Techny arborvitae get? Plan on 12 to 15 feet tall and 6 to 10 feet wide in a typical Twin Cities landscape. Sources genuinely disagree on the ceiling: some references list 10 to 15 feet, others 20 to 30 feet on very old plants. At about a foot a year, most residential plantings reach 12 to 15 feet and stay useful there for decades.

Do deer eat Techny arborvitae? Yes, heavily. Rutgers Cooperative Extension rates Thuja occidentalis "Frequently Severely Damaged," its worst deer-resistance category, and the Minnesota DNR lists white cedar among deer's preferred winter foods. Deer browse it to a clean line at about five or six feet. On sites with regular deer traffic, columnar junipers are the more durable screen.

Will rabbits kill my Techny arborvitae? They can. Rabbits feed from the packed snow surface upward, stripping foliage and bark from the lower two to three feet. Because arborvitae only regrows from living green foliage, that bald skirt is permanent. A rabbit that chews a complete ring of bark around the trunk girdles the plant and kills it outright. Hardware cloth every winter is the fix.

When should I plant arborvitae in Minnesota? Late April through May in spring, or late August through about September 20 in fall. We cut off evergreen planting in mid-to-late September because evergreens keep transpiring all winter and need root establishment before freeze-up. September is the single best planting month. Deciduous stock can go in through the end of October, but arborvitae should not.

Can I prune Techny arborvitae to keep it shorter? Yes, but with limits. Shear in late spring after the growth flush or in midsummer, never after August. Never cut into bare brown wood — arborvitae regrows only from living green foliage, so a cut past the green leaves a permanent hole. If you need a plant that stays under eight feet, buy a smaller cultivar rather than fighting Techny.

How much water does a new Techny arborvitae need? Five gallons per plant, once a week, for the first two full summers, poured slowly at the base so it soaks the root ball instead of running into the lawn. Rainfall counts. Lawn irrigation does not — sprinklers wet the surrounding clay without saturating the dense nursery root ball. Scale up for #15 and larger.

Is Techny better than Emerald Green arborvitae? For a Minnesota privacy screen, usually yes. Techny is hardier, broader, and denser, and it holds dark green color through winter rather than bronzing. Emerald Green types grow about 8 to 12 inches a year and stay narrower, which suits tight beds. Neither is browse-resistant; both get eaten on the same sites.

What should I plant instead of Techny arborvitae? On sites with rabbits, deer, road salt, or heavy wind exposure, plant columnar junipers — Taylor, Sky Rocket, or Star Power — or Black Hills Spruce where you have room. They fill in more slowly and need tighter spacing, but they are not browsed and they handle exposure far better. In a fenced yard with no browse pressure, Techny is still the better value.

Ready to plant a Techny screen?

Three Timbers Minnesota grows Techny Arborvitae from #5 through 9-foot balled-and-burlapped, and we plant privacy screens across the Twin Cities every week. If you are weighing it against the alternatives, read arborvitae vs. spruce vs. juniper first, or browse the full privacy hedge collection. Free delivery over $200, two to four business days, and our crew can plant it for you with no minimum job — call or text 612-214-1955.