Quick Answer
The best fertilizer for arborvitae is one you can apply consistently at an appropriate rate while the plant has adequate water, light, and healthy roots. Arborvitae use nitrogen as part of green vegetative growth, while potassium plays broad roles in water regulation and plant stress response. Liquid, granular, and spike fertilizers can all supply nutrients; the main differences are how they are applied, how evenly they can be distributed, and how much control the grower has over each feeding.
What Arborvitae Need From Fertilizer
Green Giant, Emerald Green, and other Thuja are evergreen plants, but that does not mean fertilizer should be used to force constant growth or correct every discoloration.
Plants need nitrogen for proteins, chlorophyll-related processes, and vegetative growth. Potassium is involved in water regulation and other normal plant functions.
Those are nutrient roles, not guarantees. Providing nitrogen does not mean a hedge will grow at a particular rate, and providing potassium does not make an arborvitae immune to winter or drought stress.
Good fertilizer use starts with the plant's actual growing conditions.
Liquid vs Granular vs Fertilizer Spikes
| Type | Advantages | Trade-offs |
|---|---|---|
| Liquid concentrate | Easy to dilute into irrigation water and distribute through the root zone; concentration can be measured each application. | Requires mixing and repeated applications according to the product directions. |
| Granular fertilizer | Can be spread across the soil surface and may require less frequent handling depending on the formulation. | Distribution depends on how evenly it is spread and how water moves nutrients into the root zone. |
| Fertilizer spikes | Simple placement and little measuring after installation. | Nutrients are concentrated in specific spots rather than being evenly distributed across the full root zone. |
None of these forms is automatically correct for every garden. A grower who wants direct control over dilution may prefer liquid fertilizer. Someone who prefers a dry application may choose granular fertilizer.
The important part is following the directions for whichever product is being used rather than combining several fertilizer types and unintentionally increasing the total nutrient input.
Why a 3.6-3-5.1 Liquid Formula Fits Arborvitae
TPS Arborvitae Fertilizer has an NPK of 3.6-3-5.1. The nitrogen is nitrate-forward, and potassium is the highest of the listed macronutrients.
That gives arborvitae a source of the main macronutrients in a liquid form that can be diluted and distributed through the root zone.
The formula is made for Green Giant, Emerald Green, and other Thuja. It should still be used as one part of normal care rather than as a shortcut around water, spacing, light, or root problems.
Green Giant vs Emerald Green Fertilizer Needs
Green Giant and Emerald Green have different natural growth habits, but both can be fed with the same arborvitae formula.
Do not try to make one variety behave like the other by changing fertilizer concentration. Genetics, maturity, site conditions, spacing, and climate all influence the plant's growth habit.
That matters especially in hedges. If an Emerald Green planting is filling in differently from a Green Giant planting, it does not automatically mean the slower-looking hedge needs stronger fertilizer.
How to Apply Liquid Arborvitae Fertilizer
Start with moist soil. Do not apply concentrated fertilizer to a severely dry root zone.
Mix 2 tablespoons per gallon of water. Use the label dilution rather than making a stronger solution.
Apply through the root zone. Spread the solution across the soil around the plant instead of pouring it against the trunk.
Follow the seasonal cadence. Apply every 1–2 weeks in spring and summer and every 4 weeks in fall and winter.
Keep checking the plant itself. If foliage begins browning, diagnose water, winter, transplant, root, and physical damage rather than simply increasing fertilizer.
When Fertilizer Is Not the Answer
Fertilizer cannot replace irrigation. A dry arborvitae needs adequate water in its root zone, not a more concentrated nutrient solution.
It also cannot repair brown tissue caused by winter exposure or physical browsing. If that is the issue you are dealing with, see why arborvitae turn brown.
Likewise, newly planted arborvitae may struggle because of transplant conditions. Check whether the root ball is becoming evenly moist and whether the planting drains properly before assuming the plant needs more nutrients.
Should You Use a High-Nitrogen Fertilizer?
More nitrogen is not automatically better. Nitrogen is necessary for vegetative growth, but forcing a higher application rate does not guarantee a denser or faster-growing hedge.
A balanced fertilizer strategy supplies nutrients while letting the plant's genetics and growing conditions determine the pace of development.
The TPS formula uses 3.6-3-5.1 rather than treating nitrogen as the only nutrient that matters.
When to Feed During the Year
The verified TPS label uses a more frequent feeding cadence during the active spring and summer period and a reduced cadence in fall and winter.
| Season | TPS Arborvitae Fertilizer cadence |
|---|---|
| Spring | Every 1–2 weeks |
| Summer | Every 1–2 weeks |
| Fall | Every 4 weeks |
| Winter | Every 4 weeks |
For a deeper seasonal explanation, see when to fertilize arborvitae. The full application procedure is in our arborvitae fertilizing guide.
Choosing Fertilizer for a Hedge
For a long hedge, distribution matters. Roots from neighboring arborvitae occupy overlapping soil, so a fertilizer that can be spread evenly through that zone is practical.
Liquid fertilizer can be mixed with water and carried along the planting row. Granular products can also work when distributed evenly and watered in according to their own directions.
Avoid judging a fertilizer only by how concentrated the numbers look on the front. Application rate and frequency determine how the product is actually used.
