3 Essential Steps to Fertilize Your Arborvitae for Thicker, Fuller Growth

Why Fertilize Arborvitae?

Arborvitae, known for their vibrant green foliage and dense growth, require proper fertilization to thrive. Fertilizing provides essential nutrients that support healthy root development, enhance disease resistance, and promote vigorous growth.

1. Choosing the Right Fertilizer

The key to effective fertilization lies in selecting the right fertilizer for arborvitae. Consider the following factors:

• Nitrogen (N): Essential for promoting vegetative growth and lush foliage.
• Phosphorus (P): Supports root development and enhances stress tolerance.
• Potassium (K): Crucial for disease resistance and cold hardiness.

Look for a balanced fertilizer with an NPK ratio of 10-10-10 or 12-6-6.

2. Timing and Frequency

Fertilize arborvitae twice a year, once in spring and again in fall. Avoid fertilizing during the summer months when excessive heat can stress plants.

Spring Fertilization (March-April): Apply a slow-release granular fertilizer to provide a steady supply of nutrients throughout the growing season.

Fall Fertilization (September-October): Use a balanced liquid fertilizer to replenish nutrients depleted over the summer.

3. Applying Fertilizer

• Broadcast Method: Sprinkle granular fertilizer evenly around the base of the arborvitae, staying about 6 inches away from the trunk.
• Trenches: Dig a shallow trench in a circle around the arborvitae, 6 inches deep and 6 inches away from the trunk. Apply fertilizer in the trench and cover with soil.
• Liquid Fertilization: Dilute liquid fertilizer according to the manufacturer's instructions and apply directly to the soil around the tree.

Common Mistakes to Avoid

• Overfertilizing: Excessive fertilizer can burn roots and damage plants.
• Using high-nitrogen fertilizers during fall: Can promote excessive growth that is susceptible to winter damage.
• Fertilizing too close to the trunk: Can damage delicate roots.

How to Tell if Your Arborvitae Needs Fertilization

• Yellowing foliage
• Stunted growth
• Sparse foliage
• Brown or scorched needle tips

Additional Tips

• Mulch: Spread a layer of organic mulch around arborvitae to retain moisture and suppress weeds.
• Iron Supplementation: In areas with alkaline soil, consider applying iron supplements to prevent iron deficiency.
• Slow-Release Fertilizers: Use slow-release fertilizers or organic fertilizers that provide nutrients over an extended period.

Table 1: Fertilizer Recommendations for Arborvitae

Table 2: Fertilizer Application Rates for Arborvitae

| Arborvitae Height (ft) | Fertilizer Amount (lb/tree) |
|---|---|---|
| 2-4 | 1/4-1/2 |
| 4-6 | 1/2-1 |
| 6-8 | 1-1 1/2 |

Table 3: Nutrient Deficiencies and Symptoms in Arborvitae

| Nutrient Deficiency | Symptoms |
|---|---|---|
| Nitrogen | Yellowing foliage, stunted growth |
| Phosphorus | Weak root development, poor stress tolerance |
| Potassium | Susceptibility to disease, brown needle tips |

Table 4: Benefits of Fertilizing Arborvitae

| Benefit | Explanation |
|---|---|---|
| Enhanced growth | Provides essential nutrients for vigorous growth |
| Disease resistance | Strengthens plants to resist pests and diseases |
| Improved root development | Encourages deeper and more extensive root systems |
| Thicker, fuller foliage | Promotes lush, healthy foliage that enhances curb appeal |
| Increased cold hardiness | Supports winter survival by replenishing nutrients |