Thin Man is a variety of American arborvitae bred for an unusually slim, upright shape, which makes it a favorite for privacy screens in tight spaces.1Google Patents. Thuja plant named ‘SMTOTM’ Most of the care that decides whether it thrives happens in the first couple of years, especially watering, and the browning many owners fear usually traces back to water, wind, or the wrong cut.
How Big Thin Man Gets and Where It Grows Best
A mature Thin Man reaches about 12 to 15 feet tall.2Greenwood Nursery. Thin Man Arborvitae | Buy Online Plants Nursery Tree Width is less settled. Sellers list it anywhere from 2 to 3 feet up to 3 to 5 feet,3GrowJoy. Thin Man Arborvitae4Great Garden Plants. Full Speed A Hedge® ‘Thin Man’ Arborvitae | Shrubs & Trees so plan for roughly 4 feet wide as a middle estimate.5Gertens. Thin Man Arborvitae It can add 2 to 3 feet of height a year,6Nature Hills Nursery. Thin Man® Arborvitae | Narrow Privacy Hedge | Nature Hills and in good conditions it can live 50 years or more.7Gertens. Thin Man Arborvitae
A hardiness zone is the USDA rating of how cold your winters get, and it’s printed on most plant tags. Thin Man is rated for zones 3 to 7 and survives down to -40°F.8Nature Hills Nursery. Thin Man® Arborvitae | Narrow Privacy Hedge | Nature Hills Some sellers rate it to zone 8.9Great Garden Plants. Full Speed A Hedge® ‘Thin Man’ Arborvitae | Shrubs & Trees It needs at least four hours of direct sun a day, anywhere from full sun to part sun.10Full Speed A Hedge. About Thin Man – Full Speed A Hedge In deep shade, expect thinner, less dense growth.
When you pick a spot along a fence or house, measure the strip first so 4 feet of width fits without the plant rubbing a wall or fence. Watch the spot across a whole day to confirm it gets those four hours of sun, since a shady morning can hide a sunny afternoon or the reverse. Look up, too: a plant that will reach 15 feet needs clearance from power lines. In zone 8 heat, afternoon shade and extra water help.
Soil and Drainage for Thin Man
Arborvitae adapt to many soils, even red clay, but they prefer moist, well-drained loam.11Wilson Bros Gardens. How To Plant, Prune, Fertilizer, Water, Grow And Care For Arborvitae Thuja Shrubs Roots need both water and air, so waterlogged or compacted clay suffocates them and slows growth.12Nature Hills Nursery. Arborvitae Growth Rate: Speed by Variety They handle soil pH from about 6.0 to 8.0, slightly acidic to alkaline.13Penn State Extension. The Mighty Arborvitae Most garden soils, typically 6.0 to 7.0, suit them without adjustment.14Wilson Bros Gardens. How To Plant, Prune, Fertilizer, Water, Grow And Care For Arborvitae Thuja Shrubs In heavy clay, mix compost into the planting area and set the root ball 1 to 2 inches above ground level.15Nature Hills Nursery. Arborvitae Growth Rate: Speed by Variety
Test drainage before you plant. Dig a hole a foot deep and fill it with water. If water still stands after several hours, the spot drains poorly. Choose a raised spot instead, or build up a low mound. Avoid places where downspouts or lawn runoff collect.
A row planted in a low or soggy spot often shows slowed growth and foliage that yellows or fades overall, even though the owner is watering carefully. Because those symptoms look like thirst, owners often add more water, which makes the problem worse. Fixing drainage is far easier before planting than after, since digging up a row of established arborvitae to raise the ground is hard on the roots.
How to Plant and Space Thin Man
Before planting, water the plant in its pot so the root ball is moist and holds together when you slide it out. Dig a hole 2 to 3 times as wide as the root ball.16Proven Winners. Arborvitae – The Ultimate Growing Guide from Proven Winners In clay soil, rough up the sides of the hole with the shovel, since smooth, glazed walls can make roots reluctant to push out. If roots circle the pot, loosen them,17Proven Winners. Arborvitae – The Ultimate Growing Guide from Proven Winners either by teasing them apart or making a few shallow cuts so they grow outward instead of continuing to wrap around.
Set the top of the root ball at or slightly above ground level to allow for settling.18Proven Winners. Arborvitae – The Ultimate Growing Guide from Proven Winners Then backfill, tamp lightly to remove air pockets, and water well.19Proven Winners. Arborvitae – The Ultimate Growing Guide from Proven Winners
Arborvitae spacing ranges from 2 to 10 feet depending on variety.20Proven Winners. Arborvitae – The Ultimate Growing Guide from Proven Winners For a narrow type like Thin Man, about 2 to 4 feet apart gives a solid screen. Closer spacing fills in faster, but the plants compete more for water. Leave room behind the row so you can reach it for watering and trimming, and keep 2 feet or more from fences so air moves.
Roots are shallow, mostly within the branch spread, reaching about 18 to 24 inches deep on large arborvitae.21Ask Extension. Arborvitae roots are killing my vegetable garden Keep vegetable beds a few feet back, since the roots compete for water.
Spring and early fall are the best times to plant, because roots get time to settle before heat or freezing. Summer planting works only with very regular watering. Fall plantings need watering until the ground freezes.
How Much to Water Thin Man
- First season: deep soak every other day when temperatures are above 70°F.22Glover Nursery. Arborvitae Planting and Care Guide
- Second season: every 2 to 3 days, more in peak heat.23Glover Nursery. Arborvitae Planting and Care Guide
- Third season on: every 3 to 4 days in warm weather.24Glover Nursery. Arborvitae Planting and Care Guide
Consistent water for the first two growing seasons lets roots settle, and plants more than four feet tall when planted need it longer.25Plant Addicts. Watering Arborvitae Even established arborvitae are not truly drought-tolerant and may need water in dry spells.26Penn State Extension. The Mighty Arborvitae Constantly soggy soil causes problems too.27Wilson Bros Gardens. How To Plant, Prune, Fertilizer, Water, Grow And Care For Arborvitae Thuja Shrubs
To check whether it needs water, push a finger or trowel 2 to 3 inches into the soil. If it’s dry at that depth, soak; if it’s wet, wait. A light rain usually doesn’t soak the soil deeply, so check before skipping a watering. A layer of mulch 2 to 3 inches deep keeps moisture in, as long as you keep it off the trunk.
A soaker hose or drip line along the row reaches all plants evenly. Water at the base rather than spraying the foliage, and run the water slowly so it sinks in instead of running off.
The listed schedules are starting points. Stretch the interval after rain or a cool spell, and shorten it in hot, windy weather. Sandy soil needs water more often, while clay holds moisture longer.
Fertilizing and Pruning Thin Man
Feed in early spring, ideally based on a soil test, at about one pound per 100 square feet of root area before rain.28Home Garden Education Office. Arborvitae A balanced slow-release tree and shrub fertilizer such as 10-10-10 works.29Green Giant Trees. Guide: How to Fertilize Green Giant Arborvitae Don’t fertilize in late summer, since new growth won’t harden off before winter.30Home Garden Education Office. Arborvitae Heavy nitrogen encourages spider mites, so lean toward slow-release.31Hortsense. Arborvitae: Spider mites
A healthy Thin Man in decent soil may need little or no feeding. Pale or slow-growing plants are where feeding helps. Too much fertilizer can burn roots and push soft growth.
Thin Man rarely needs pruning because it grows naturally narrow.32GrowJoy. Thin Man Arborvitae New green growth only comes from younger green wood,33Bower & Branch. How To Prune And Care Tips For Arborvitae Trees so cutting back to brown, needle-free parts leaves permanent bare spots.34gardeningtheme.com. How to trim arborvitae If you do shape it, keep the base slightly wider than the top so light reaches the lower branches.35gardeningtheme.com. How to trim arborvitae Avoid pruning in wet weather, when fungal spores spread.36Center for Agriculture, Food, and the Environment at UMass Amherst. Arborvitae Needle Blight
A light trim done right means taking only the soft green tips, in late spring or early summer. Small, frequent trims beat one hard cut. Use sharp, clean shears to limit entry points for fungus. Dead or broken branches can come out any time it’s dry.
Protecting Thin Man in Winter
Winter burn is browning of evergreen foliage on exposed plants in harsh winters.37Wisconsin Horticulture. Winter Burn Evergreens never fully go dormant, so dry winds pull moisture from the branches while frozen roots can’t replace it.38Ask Extension. Winter Burn Arbor Vitaes It’s worse in near-snowless winters, since snow insulates roots.39Ask Extension. Winter Burn Arbor Vitaes Keep watering in fall right up until the ground freezes.40Ask Extension. Winter Burn Arbor Vitaes
For exposed rows, a burlap screen on the windward side cuts drying wind, and mulch helps hold soil moisture into winter. Gently brush off heavy snow so the narrow stems don’t splay. If branches brown, wait until spring growth appears before cutting, since some recover.
Plants on open sides facing the prevailing wind, or beside a road or driveway, are most at risk. Plants sheltered by a house or other trees often come through the same winter unmarked. Salt spray from roads or de-icing near a driveway can also brown foliage, so keep salt away from the row.
Pests and Diseases That Brown Thin Man
Older inner foliage browns and drops naturally each fall. Browning at the tips, speckling, or a whole plant fading is not normal. Check soil moisture first, since water problems are the most common cause.
Spider mites are tiny eight-legged pests that leave fine webbing and yellowish speckling, then brown foliage.41Hortsense. Arborvitae: Spider mites Shake a branch over white paper to spot the moving specks. Hose them off with a strong stream of water.42Hortsense. Arborvitae: Spider mites Avoid broad-spectrum insecticides, which kill the ladybugs and lacewings that eat mites.43Hortsense. Arborvitae: Spider mites Drought-stressed plants are more vulnerable.44Hortsense. Arborvitae: Spider mites
Bagworms are a recognized arborvitae pest that can be controlled with insecticides.45Insecticide and Acaricide Tests. Control of Bagworms on Arborvitae, 1979 You can also hand-pick the small hanging bags in winter or early spring, before the eggs inside hatch.
Needle blight and root rot take hold when the site stays wet or the plant’s interior never dries.46WascoNursery.com. Arborvitae Needle Blight: 5 Symptoms and the Best Fix Blight starts at needle tips, turning them pale, yellow, or brown.47Center for Agriculture, Food, and the Environment at UMass Amherst. Arborvitae Needle Blight Prune out and discard infected parts, since dead shoots harbor the fungus, and avoid overhead sprinklers that wet the foliage.48Center for Agriculture, Food, and the Environment at UMass Amherst. Arborvitae Needle Blight Root rot shows as discoloring that spreads from the bottom up, with soft, dark roots that break easily.49WascoNursery.com. Arborvitae Needle Blight: 5 Symptoms and the Best Fix50Pacific Northwest Pest Management Handbooks. Arborvitae-Root Rot Have a plant clinic confirm it.51Pacific Northwest Pest Management Handbooks. Arborvitae-Root Rot Walk along the row every couple of weeks in summer and check both the outer tips and the inner branches, since problems often start out of sight.
Will Deer Eat Thin Man
One seller calls Thin Man among the more deer-resistant arborvitae.52Nature Hills Nursery. Thin Man® Arborvitae | Narrow Privacy Hedge | Nature Hills Another nursery notes that only the ‘Elegantissima’ variety of this species is truly deer-resistant.53Waverly Farm. Plant of the Month: Thuja Occidentalis ‘Thin Man’ Where deer are common, use netting during establishment.54Nature Hills Nursery. Thin Man® Arborvitae | Narrow Privacy Hedge | Nature Hills
Damage shows as stripped lower branches, up to the height deer can reach. Deer lack upper front teeth, so they leave ragged, torn edges rather than clean cuts, and the upper part of the plant usually stays untouched. Tracks or droppings nearby help confirm it, since other animals can also damage plants.
Netting or fencing matters most in late winter, when food is scarce. Repellent sprays need reapplying after rain.
Growing Thin Man in Containers and for Birds
Arborvitae in containers need quality all-purpose potting mix and drainage holes.55Proven Winners. Arborvitae – The Ultimate Growing Guide from Proven Winners® Use that mix rather than garden soil, which can pack down in a pot. Keep the holes clear so excess water can escape, and raise the pot slightly on feet or bricks.
If you do pot a Thin Man, pick a large, heavy pot so the tall plant doesn’t tip. Pots dry out fast and need frequent watering. Roots in pots freeze more easily, so plant it in the ground within a few years.
In the ground, dense, flat foliage sprays give birds cover and nesting sites.56Master Gardeners of Northern Virginia. Native Woody Plants Provide Shelter and Nesting Sites for Wildlife Mature arborvitae become winter shelter, which is useful near feeders.57My Northern Garden. Best Trees for Birds in the North