Danica arborvitae

Sun

Full sun to partial shade; dense growth is best with at least 6 hours of sun. Light afternoon shade helps in hotter locations.

Water

Keep evenly moist, especially during establishment and dry summers; neither drought nor waterlogged roots are well tolerated.

Soil

Moist, well-drained loam or clay loam; tolerates acidic to alkaline soil. Avoid very dry sand and ground that stays saturated.

Height

2-3 ft (0.6-0.9 m)

Spread

2-3 ft (0.6-0.9 m)

Foliage

Evergreen. Fine, flattened sprays of soft, scale-like green leaves form a dense globe. Foliage may take on bronze tones in cold weather.

Growth

Slow, usually about 1-3 in (2.5-7.5 cm) a year; old plants may eventually exceed the usual size.

Care needed

Low

• Cold hardy
• Wildlife

Northern hemisphere months. In Australia, shift them by six.

Difficulty

Easy

Toughness

Fairly tough

Pick your zone, country, light and whether you have pets.

1. Planting day

   1.6 ft (0.5 m)

2. After 1 year

   1.7 ft (0.53 m)

3. After 2 years

   1.8 ft (0.56 m)

4. After 3 years

   1.9 ft (0.59 m)

5. After 5 years

   2.2 ft (0.66 m)

About 8 years to full size.

From a typical nursery size, at an average rate for this kind of plant. A rule of thumb, not a forecast.

Cats and dogs

Toxic

Native to

the US and Canada

Growth rate

Slow

• Water deeply when the root zone begins to dry during the first two growing seasons; continue watering during prolonged dry spells.
• Spread 2-3 in (5-8 cm) of organic mulch over the roots, keeping it clear of the stems.
• Feed lightly in spring only if growth is weak or soil is poor; avoid high-nitrogen feeding late in the growing season.
• Water before the ground freezes if autumn has been dry, and shelter exposed plants from drying winter winds.
• Use a container with drainage holes and check its moisture frequently; container roots need extra protection in severe winters.

Pruning. Little pruning is needed. Lightly trim uneven green tips in late spring or early summer, and remove dead or damaged branches; do not cut into bare brown wood, which usually will not regrow.

Early spring

Check for winter damage and remove dead or broken shoots once new growth makes their condition clear.

Spring

Plant while conditions are cool, water thoroughly and mulch the root area.

Late spring

Lightly trim stray green shoots only if the natural globe needs tidying.

Summer

Water during dry periods and inspect browning foliage for mites, bagworms or dry roots.

Autumn

Water well during dry weather before winter; some shedding of older inner foliage is normal.

Winter

Gently brush off loose, heavy snow before branches bend; do not knock or pull at frozen foliage.

• Repeat evenly spaced globes along a path for a low, formal rhythm.
• Place beside a doorway or terrace in a large, well-drained container for year-round structure.
• Use at the front of a mixed shrub border, contrasting its rounded shape with upright grasses and flowering perennials.
• Plant as a low, informal edging around a small bed, allowing enough room for the mature width.

Garden styles it suits: Formal, Contemporary minimal, Traditional, Small-space, Low-maintenance and Winter interest.

Plant it with: Coral bells, Hostas, Japanese forest grass, Astilbes, Dwarf spireas and Siberian irises.

Wildlife: Dense foliage provides small-scale shelter for birds and invertebrates, although this dwarf cultivar offers less habitat than a full-sized tree. Deer may browse it heavily where they are common.

• Winter burn: exposed foliage browns when roots cannot replace lost moisture. Water during dry autumn weather, mulch the roots and use a windbreak at exposed sites.
• Root rot: persistent wetness causes declining growth and branch death. Improve drainage or move the plant to a better-drained position; do not keep watering already saturated soil.
• Spider mites: fine stippling and bronzing can develop in dry conditions. Check affected sprays over white paper, rinse foliage with water and use a labelled mite treatment only if infestation persists.
• Bagworms, especially in North America: caterpillars in hanging cases strip foliage. Hand-pick cases before eggs hatch, or treat very young larvae with a locally approved product.

Treat the foliage, young shoots and their oils as potentially toxic to people, cats, dogs and horses if eaten. They contain thujone and other compounds that can cause digestive upset; large amounts or concentrated essential oil can cause serious poisoning. Sap or foliage may also irritate sensitive skin.

• Hetz Midget arborvitae (Thuja occidentalis 'Hetz Midget')

  Another compact green globe with very similar foliage; it can become somewhat larger. Young plants are difficult to distinguish reliably without a label.

• Little Giant arborvitae (Thuja occidentalis 'Little Giant')

  Forms a larger rounded shrub, commonly reaching about 4-5 ft (1.2-1.5 m), rather than remaining as small as 'Danica'.

• Teddy arborvitae (Thuja occidentalis 'Teddy')

  Has conspicuously fine, soft, juvenile needle-like foliage rather than the mainly flattened, scale-leaved sprays of 'Danica'.

Arborvitae means 'tree of life' in Latin, and occidentalis means 'western', distinguishing this North American species from its eastern relatives.

Propagation. Take semi-ripe cuttings in late summer and root them in a free-draining medium under humid conditions. Rooting can be slow; seed will not reliably produce plants true to 'Danica'.

Accepted botanical name

Thuja occidentalis

In the US and Canada

Native in Canada and the lower 48 states.

Native range

Connecticut, Illinois, Indiana, Kentucky, Maine, Manitoba, Maryland, Masachusettes, Michigan, Minnesota, New Brunswick and New Hampshire.

Measured

Soil pH 5.2 to 7. Average height 1460 cm.

Sources: GBIF (CC BY 4.0), USDA PLANTS and Trefle (CC BY 4.0). The care and design notes are LandscapeGPT's own.