Emerald green arborvitae thrives when planted in early spring or late summer to avoid heat stress. Knowing when to plant emerald green arborvitae is the first step to getting a healthy, dense privacy screen. Get the timing wrong, and you risk losing your investment to frost or drought.
These evergreens are popular for a reason. They grow fast, stay green all year, and need little pruning. But they are picky about when they go into the ground. Let’s break down the best planting windows so you can succeed.
When To Plant Emerald Green Arborvitae
The best time is early spring, just after the last frost. This gives the roots a full growing season to establish before winter. The second best window is late summer to early fall, about 6 to 8 weeks before the first hard frost.
Planting in summer heat is risky. The roots struggle to take up water, and the foliage can scorch. Winter planting is even worse because frozen ground stops root growth entirely.
Why Early Spring Is The Ideal Window
Spring soil is cool and moist. This reduces transplant shock. The air temperatures are mild, so the tree can focus energy on root development instead of fighting heat.
- Soil temperature between 45°F and 65°F is perfect.
- Rainfall is usually more consistent in spring.
- You have the whole growing season to water and monitor.
If you plant in March or April, your arborvitae will be well-rooted by July. This makes it much more tolerant of summer dry spells.
Late Summer Planting: The Second Best Option
Late August through mid-September works well in most climates. The intense summer heat has passed, but the soil is still warm enough for root growth. The cooler air reduces water loss from the leaves.
You need to plant at least 6 weeks before the ground freezes. This gives the roots time to anchor. In colder zones (4 and 5), aim for early September. In warmer zones (6 and 7), you can push into October.
One risk: a sudden early frost can damage new, tender roots. Mulching heavily after planting helps insulate the soil.
What About Planting In Summer?
It is possible, but not recommended unless you have no choice. If you must plant in June, July, or August, you need to be extra careful.
- Water deeply every day for the first two weeks.
- Provide afternoon shade with a temporary screen.
- Mulch with 3 inches of organic material to keep roots cool.
- Expect some browning or needle drop from heat stress.
Even with perfect care, summer-planted arborvitae have a higher failure rate. The roots simply cannot keep up with the water demand from the leaves.
Winter Planting: Avoid It
Planting in frozen ground is a waste of money. The roots cannot grow, and the tree will dry out from wind exposure. If you buy a tree in winter, keep it in a pot in a sheltered spot until spring.
In very mild climates (zones 8 and 9), winter planting can work. But for most of us, it is a bad idea.
How Soil Temperature Affects Planting Success
Soil temperature matters more than air temperature. Arborvitae roots stop growing when soil drops below 40°F. They grow best when soil is between 50°F and 70°F.
Use a soil thermometer to check. Insert it 4 inches deep in the morning. If it reads 45°F or higher, you can plant. If it is below 40°F, wait.
Cold soil delays root growth and can cause root rot. Warm soil encourages quick establishment.
Testing Your Soil Before Planting
Before you dig, do a simple drainage test. Dig a hole 12 inches deep and fill it with water. Let it drain completely, then fill it again. If the water is still there after 24 hours, your soil drains too slowly. You will need to amend it or plant in a raised bed.
Arborvitae hate wet feet. Soggy soil leads to root rot and yellowing needles. If your soil is heavy clay, mix in compost or sand to improve drainage.
Also check the pH. These trees prefer slightly acidic soil, between 6.0 and 7.0. A simple test kit from a garden center will tell you if you need to add sulfur or lime.
Step-By-Step Planting Guide For Emerald Green Arborvitae
Follow these steps for the best results. Timing is just one part of the equation. Proper planting technique is equally important.
Step 1: Choose The Right Location
Pick a spot with full sun to partial shade. Six hours of direct sunlight is ideal. Too much shade makes the tree grow loose and thin.
Space them 3 to 4 feet apart for a dense hedge. If you want individual specimens, space them 6 to 8 feet apart.
Avoid planting too close to buildings or fences. The roots need room to spread, and the foliage needs airflow to prevent disease.
Step 2: Dig The Hole Correctly
Dig a hole that is twice as wide as the root ball but no deeper. The top of the root ball should sit slightly above ground level. Planting too deep is a common mistake that suffocates the roots.
Rough up the sides of the hole with your shovel. This helps roots penetrate the surrounding soil instead of circling.
Step 3: Prepare The Root Ball
If the tree is in a pot, gently loosen the roots. Cut any that are circling the bottom. If the tree is burlapped, remove all twine and wire baskets. These can girdle the trunk as the tree grows.
Soak the root ball in a bucket of water for 15 minutes before planting. This ensures it is fully hydrated.
Step 4: Backfill And Water
Fill the hole halfway with the original soil. Do not add fertilizer at planting time. It can burn the roots. Water deeply to settle the soil, then fill the rest of the hole.
Create a small soil ring around the edge of the hole to hold water. This directs moisture to the roots instead of running off.
Step 5: Mulch And Stake
Apply 2 to 3 inches of mulch around the base. Keep it away from the trunk to prevent rot. Mulch conserves moisture and moderates soil temperature.
Staking is usually not needed unless you are in a very windy area. If you stake, use soft ties and remove them after one year.
Watering Schedule After Planting
Water is critical in the first year. The roots are shallow and cannot reach deep moisture yet.
- First week: Water every day.
- Weeks 2 to 4: Water every other day.
- Weeks 5 to 12: Water twice a week.
- After 3 months: Water once a week if no rain.
Adjust based on your climate. In hot, dry weather, you may need to water more often. In cool, rainy weather, cut back. Overwatering is just as bad as underwatering.
Check soil moisture by sticking your finger 2 inches into the ground. If it feels dry, water. If it feels wet, wait.
Signs Of Overwatering
Yellowing needles, especially on lower branches. Soft, mushy roots. A foul smell from the soil. If you see these, stop watering and let the soil dry out.
Signs Of Underwatering
Browning tips, drooping branches, and needles that feel brittle. The tree may look dull instead of vibrant green. Water deeply if you see these signs.
Fertilizing After Planting
Do not fertilize at planting time. Wait until the next spring. Use a slow-release fertilizer formulated for evergreens. Apply it in early spring before new growth starts.
Too much nitrogen can cause rapid, weak growth that is prone to pests. Follow the package directions exactly. Less is more with these trees.
If your soil is poor, you can mix compost into the planting hole. But avoid synthetic fertilizers until the tree is established.
Common Mistakes To Avoid
Even experienced gardeners make these errors. Avoid them to keep your arborvitae healthy.
- Planting too deep: This is the number one killer. The root ball must be above ground level.
- Planting too close together: Crowded trees compete for water and air. They also get less sunlight.
- Skipping mulch: Bare soil dries out fast and heats up. Mulch is cheap insurance.
- Ignoring wind: These trees are not wind-tolerant. Plant them in a sheltered spot or use a windbreak.
- Pruning too early: Let the tree grow naturally for the first two years. Pruning stresses young plants.
Regional Planting Considerations
Your local climate changes the ideal planting time. Here is a rough guide by region.
Northern Zones (3 To 5)
Plant in early spring, as soon as the ground thaws. Late summer planting is risky because winter comes early. Aim for April or May. If you plant in fall, do it by mid-August.
Central Zones (6 To 7)
Spring and fall both work well. Plant in March or April for spring. For fall, plant in September or early October. These zones have milder winters, so fall planting is more reliable.
Southern Zones (8 To 9)
Fall and winter are best. Avoid summer heat. Plant from October through February. The mild winters allow roots to grow all year. Just watch for dry spells.
Frequently Asked Questions
Can I plant emerald green arborvitae in the rain?
Yes, but only if the soil is not waterlogged. Planting in mud compacts the soil and suffocates roots. Wait until the ground is damp but not saturated.
How late in fall can I plant emerald green arborvitae?
You need at least 6 weeks before the ground freezes. In most zones, that means mid-September to early October. In warmer zones, you can plant into November.
What happens if I plant emerald green arborvitae too late?
The roots will not establish before winter. The tree may suffer frost heave, where the ground freezes and pushes the roots up. It can also dry out from winter winds.
Should I plant emerald green arborvitae in the morning or evening?
Morning is better. The tree has the whole day to settle before night. Evening planting can leave the roots wet overnight, increasing rot risk.
Can I plant emerald green arborvitae in clay soil?
Yes, but you must amend it. Mix in compost or coarse sand to improve drainage. Plant on a slight mound to keep roots above water.
Final Tips For Success
Timing is important, but it is not everything. Good soil preparation, proper watering, and the right location matter just as much. Do not rush the process.
If you miss the ideal planting window, wait. It is better to keep a tree in its pot for a few months than to plant it at the wrong time. A potted tree can survive with regular watering. A poorly timed planting might not.
Emerald green arborvitae are forgiving once established. They grow fast and stay beautiful for decades. Give them the right start, and they will reward you with a lush, green screen that adds privacy and value to your property.
Remember the key: cool soil, mild air, and consistent moisture. Stick to early spring or late summer, and you will have healthy trees that thrive for years.