When To Fertilize Emerald Green Arborvitae

Knowing when to fertilize Emerald Green Arborvitae is the key to keeping your hedge lush and healthy. This guide will walk you through the essential seasonal feeding schedule to ensure your trees thrive for years to come.

These popular evergreens are relatively low-maintenance, but they do benefit from the right nutrition at the right time. Applying fertilizer at the incorrect season can do more harm than good, leading to weak growth or even damage. Let’s break down the simple calendar you should follow.

The best time to feed your arborvitae is in the early spring, just as the ground thaws and before new growth begins. This typically falls in late March to early April for most climates. A second, lighter application can be made in late fall to support root health before winter dormancy.

Never fertilize in late summer or early fall. This can stimulate tender new growth that won’t harden off before the first frost, making it susceptible to winter kill. Stick to the spring window for the main feeding.

Why Timing Matters So Much

Fertilizer provides nutrients that fuel growth. In spring, the tree is naturally ready to push out its vibrant green foliage. Feeding it then supports this burst of energy.

Fall feeding is different. The goal isn’t top growth but to strengthen the roots. A mild fertilizer in October helps the roots store energy, leading to a stronger comeback next spring. Missing these windows means the tree won’t get the full benefit.

Signs Your Arborvitae Needs Food

How can you tell if your tree needs help? Look for these clues:

Faded or yellowish-green foliage instead of a rich emerald color.
Slower than normal growth or sparse areas in the hedge.
Needles that look thin or are dropping more than usual.
Overall lack of vigor compared to neighboring plants.

Choosing the Right Fertilizer

Selecting a suitable product is just as important as timing. For Emerald Green Arborvitae, a balanced, slow-release fertilizer is ideal.

Look for a formula labeled for evergreens, trees, and shrubs.
A balanced N-P-K ratio like 10-10-10 or 14-14-14 works well.
Slow-release granules are best—they feed the tree gradually over months.
You can also use an organic option like espoma plant-tone.

Avoid quick-release, high-nitrogen lawn fertilizers. They can cause rapid, weak growth and may burn the roots. Stick with products designed for trees.

How to Apply Fertilizer: A Step-by-Step Guide

Follow these simple steps for a successful feeding:

Water the soil around your arborvitae thoroughly a day before applying fertilizer. This prevents root shock.
Measure the correct amount based on the product label and the size of your tree. When in doubt, use less.
Spread the granules evenly on the soil starting a few inches from the trunk and extending out to the drip line (the edge of the branches).
Gently rake the fertilizer into the top inch of soil to help it begin to incorporate.
Water deeply again after application to activate the granules and move nutrients toward the roots.

The Essential Seasonal Feeding Schedule

Here is your simple, year-round guide to nourishing your arborvitae.

Early Spring (Main Application)

This is your most important feeding. Apply your chosen slow-release fertilizer as soon as the ground is workable. It sets the tone for the entire growing season, promoting dense, green growth and supporting the tree’s natural cycle.

Late Fall (Optional Root Boost)

About 4-6 weeks before the ground typically freezes, you can apply a light dose of fertilizer. Use half the rate recommended on the bag. This fall feeding is not about foliage but about giving the root system some extra reserves.

Summer & Winter: The No-Feed Zones

Do not fertilize in the heat of summer. The tree can be stressed from heat and drought, and fertilizer can add to that stress. Winter is a time of dormancy; the tree cannot use nutrients, and they will simply leach away or sit unused.

Common Mistakes to Avoid

Even with good intentions, it’s easy to make errors. Steer clear of these pitfalls:

Over-fertilizing: More is not better. It can burn roots and cause excessive, leggy growth.
Fertilizing at the wrong time (especially late summer).
Placing fertilizer directly against the trunk, which can cause rot and burn.
Ignoring soil pH. Arborvitae prefer slightly acidic to neutral soil. A soil test can help.
Forgetting to water before and after application, which is crucial for nutrient uptake.

Additional Care Tips for Healthy Growth

Fertilizer is just one piece of the puzzle. For the healthiest arborvitae, combine your feeding schedule with these practices:

Watering: Provide about 1 inch of water per week, especially during dry spells. Deep, infrequent watering is better than frequent sprinkles.
Mulching: Apply a 2-3 inch layer of organic mulch around the base. Keep it a few inches away from the trunk. This conserves moisture and regulates soil temperature.
Pruning: Light pruning in early spring or mid-summer can maintain shape. Avoid cutting back into old wood where no green needles grow.

By combining proper feeding with good overall care, you’ll have a robust, beautiful hedge that provides privacy and greenery for many seasons. Remember, consistency is more important than any single heroic effort.

Frequently Asked Questions (FAQ)

Can I fertilize my Emerald Green Arborvitae when I plant it?

No. When planting, avoid adding fertilizer to the hole. You can amend the soil with compost, but wait until the following spring to apply a balanced fertilizer. This lets the tree establish its roots first without stress.

Is Miracle-Gro good for arborvitae?

You can use a product like Miracle-Gro Shake ‘n Feed for trees and shrubs, which is a slow-release formula. Always follow label instructions carefully. A generic balanced fertilizer works just as well, often for a lower cost.

How often should you really feed them?

For established trees, once a year in early spring is usually sufficient. If your soil is very poor or you see signs of deficiency, the late fall feeding can be added. Young trees benefit from the annual spring feeding to support there growth.

What if my arborvitae is turning brown?

Browning can have many causes besides lack of fertilizer. It could be due to winter burn, drought stress, pest like bagworms, or disease. Assess watering, check for pests, and ensure proper planting site before assuming it’s a nutrient issue. Fertilizer won’t fix those problems.

Can I use lawn fertilizer on my arborvitae hedge?

It’s not recommended. Lawn fertilizers are often high in nitrogen and quick-release, which can promote excessive, soft growth that’s vulnerable to cold and pests. They also may not contain the micronutrients that evergreens appreciate. Use a product formulated for trees.