Quick Answer
Fertilize arborvitae by applying diluted fertilizer over the active root zone rather than concentrating it against the trunk. TPS Arborvitae Fertilizer is mixed at 2 tablespoons per gallon of water; the verified label schedule is every 1–2 weeks in spring and summer and every 4 weeks in fall and winter. For newly planted arborvitae, establishment, moisture, and root health come before pushing nutrition.
Start With the Condition of the Arborvitae
Before fertilizing, decide whether you are dealing with an established hedge or a recently planted arborvitae.
An established plant with healthy roots can use supplemental nutrients as part of normal seasonal growth. A newly planted arborvitae is different because its first challenge is establishing roots in the surrounding soil.
If a new planting is wilting, browning, or drying out, fertilizer should not automatically be the first response. Check the planting depth, root-zone moisture, drainage, and whether the root ball is actually becoming wet when you irrigate.
Fertilizer provides nutrients. It does not correct transplant shock or a dry root ball.
How to Fertilize Established Arborvitae
Arborvitae roots spread through the soil around the plant rather than taking up nutrients only at the trunk. Apply diluted fertilizer across the root zone so it reaches the soil where active roots are growing.
Check soil moisture first. Apply fertilizer to moist soil rather than a severely dry root zone.
Mix 2 tablespoons per gallon of water. Keep the dilution at the verified label rate.
Apply across the root zone. Distribute the solution around the plant instead of dumping it in one spot beside the trunk.
Follow the seasonal cadence. Feed every 1–2 weeks in spring and summer and every 4 weeks in fall and winter according to the label.
Keep normal watering separate in your mind. Fertilizer is not a replacement for adequate root-zone moisture.
How to Fertilize an Arborvitae Hedge Row
With a hedge, the common mistake is treating each trunk as though it has an isolated circle of roots. Established arborvitae planted in a row develop root zones that overlap.
Think of the planting as a continuous strip of soil. Apply the mixed fertilizer evenly along the hedge's root zone rather than pouring a large amount beside each stem.
The goal is even distribution. Avoid concentrating fertilizer at the base of the trunks, where most of the active absorbing roots are not located.
If the hedge is showing browning, identify the cause before assuming it needs more fertilizer. Our arborvitae browning guide separates common moisture, winter, animal, and seasonal patterns.
What to Do With Mulch Before Fertilizing
Mulch can help moderate moisture around an arborvitae, but it should not be piled directly against the trunk.
You do not need to remove the entire mulch layer each time you feed. The important thing is that the diluted solution reaches the soil beneath it rather than running away from the root zone.
If mulch has formed a dense or water-shedding surface, move it enough to confirm that water can reach the soil. Keep the trunk area open rather than building a mound around the stem.
Newly Planted vs Established Arborvitae
| Situation | First priority | Role of fertilizer |
|---|---|---|
| Recently planted arborvitae | Root establishment and consistent moisture | Secondary to getting the root zone functioning properly. |
| Established arborvitae in active growth | Normal light, water, and soil conditions | Supplies nutrients used in ongoing foliage and root growth. |
| Plant with sudden browning | Identify winter, drought, transplant, animal, or root stress | Do not assume additional fertilizer will correct the damage. |
| Healthy hedge with ongoing growth | Maintain consistent care | Follow the labeled seasonal feeding schedule. |
What Is in Arborvitae Fertilizer?
TPS Arborvitae Fertilizer has an NPK of 3.6-3-5.1. The nitrogen is nitrate-forward, and potassium is the highest of the three listed macronutrients.
Nitrogen is involved in foliage and vegetative growth. Potassium has broad roles in plant water regulation and stress response. Those nutrient functions do not mean fertilizer can prevent winter burn or reverse drought damage.
The formula is intended for Green Giant, Emerald Green, and other Thuja. For more detail on choosing among liquid, granular, and spike-type products, see our guide to fertilizer for arborvitae.
Spring and Summer Feeding
Spring and summer are the label's more frequent feeding period. Apply the diluted fertilizer every 1–2 weeks.
This is also when the plant's overall growing conditions matter most. Fertilizer works as one part of the system alongside adequate soil moisture, light, and functioning roots.
Do not increase the concentration in an attempt to make a hedge fill in faster. Variety, age, spacing, light, soil, water, and root establishment all influence growth.
Fall and Winter Feeding
The verified label reduces feeding to every 4 weeks in fall and winter.
That is a lower-frequency schedule than spring and summer. Follow the product directions instead of carrying the active-season cadence unchanged through the colder part of the year.
For a more focused seasonal discussion, see when to fertilize arborvitae.
Do Not Fertilize to Fix Browning
Brown arborvitae foliage can come from several unrelated causes. Winter exposure, dry soil, transplant stress, animal browsing, root problems, and normal interior foliage shedding can all change the plant's appearance.
Fertilizer can address nutrition when nutrition is actually the limiting factor. It cannot turn dead brown foliage green again, repair browsed branches, or supply missing water to dry roots.
Diagnose the pattern first, then decide whether feeding belongs in the response.
Seasonal Timeline
| Season | Feeding cadence | Care focus |
|---|---|---|
| Spring | Every 1–2 weeks | Active growth, moisture, and root-zone coverage. |
| Summer | Every 1–2 weeks | Keep water and feeding separate; fertilizer does not replace irrigation. |
| Fall | Every 4 weeks | Reduce feeding frequency according to the label. |
| Winter | Every 4 weeks | Watch moisture and seasonal stress rather than increasing fertilizer. |
