Thuja Green Giant

Thuja Green Giant is hardy in USDA zones 5 to 8 and grows best in full to partial sun (at least six hours of direct light for the densest growth). It is not fussy about soil but performs best in moist, well-draining ground; avoid spots where water pools.

Planting

1. Choose a site with full to part sun and room for the mature 30 ft. width — keep it well clear of foundations, septic lines, and power lines overhead.
2. Work the soil so it drains freely; loosen heavy clay or amend with compost to improve structure.
3. Dig each hole twice as wide as the root ball but no deeper than the root ball is tall.
4. Set the plant so the root flare (where the trunk widens into roots) sits right at or just above grade — never bury the trunk.
5. Backfill with native soil, firm gently to remove air pockets, and water in deeply to settle the roots.
6. Mulch 2 to 3 inches over the root zone, pulling it a few inches back from the trunk. For a privacy hedge, space plants about 5 to 6 ft. apart in a single row for a solid screen, or stagger two rows about 8 ft. apart for an extra-dense windbreak.

Care & maintenance

• Water. Water deeply and regularly through the first one to two growing seasons while roots establish. Evergreens keep losing moisture in winter, so water during dry fall and winter spells to prevent desiccation and browning.
• Feed. Apply a light, slow-release evergreen or conifer fertilizer in early spring. Established plants rarely need much.
• Light. Full to part sun gives the densest, most uniform growth; too much shade thins the foliage.
• Prune. Little pruning is needed. To shape or hold a height, shear the soft green outer growth in late spring or summer — arborvitae tolerates shearing well and will refill the cut surface as long as you stay in the green foliage rather than cutting deep into bare, brown inner wood.
• Spacing. For a privacy row, plant 5 to 6 ft. on center; give specimens the full 30 ft. of width to spread naturally.
• Pests & disease. Generally trouble-free and more disease-resistant than common arborvitae. Watch for bagworms (hand-pick the small spindle-shaped bags before they multiply) and treat any spider mites in hot, dry weather.
• Winter care. In snowy climates, gently brush heavy wet snow off the branches to prevent the upright form from splaying or breaking.

How far apart should I plant them for a privacy hedge?

For a fast, solid screen, space Thuja Green Giant about 5 to 6 ft. apart in a single row. If you want an extra-thick windbreak or sound buffer, stagger two rows roughly 8 ft. apart. Closer spacing fills in sooner but the plants will compete more as they mature.

How fast does it grow and how soon will it fill in?

It is one of the fastest evergreens you can plant, often adding 3 ft. or more of height per year once established. Planted at the recommended spacing, a row typically grows together into a continuous screen within roughly three to five years.

How tall and wide will it get?

Expect a mature height of 30 to 50 ft. and a spread of about 30 ft. in a broad pyramidal shape. You can shear it annually to hold it at a more manageable hedge height if you don't want the full size.

Is it evergreen year-round?

Yes. The dense green foliage stays on the plant through all four seasons, so your privacy screen never thins out or drops. Foliage can take on a slightly bronzed tint in hard winter cold and greens back up in spring.

Is it deer resistant?

No. Like other arborvitae, Thuja Green Giant is readily browsed by deer, especially in winter when other food is scarce. In areas with heavy deer pressure, protect young plants with fencing or repellents until they grow tall enough that the foliage is out of reach.

Why is my Green Giant turning brown?

A little browning of the oldest interior foliage in fall is normal seasonal shedding. Larger brown patches usually point to one of a few causes:

• Drought or winter desiccation. The most common cause — water deeply during dry stretches, including dry fall and winter weather.
• Recent transplant. New plants often brown while roots establish; keep them consistently watered.
• Bagworms or spider mites. Check for the small spindle-shaped bags or fine webbing and treat promptly if found.