Fertilizing Arborvitae: A 50-Step Guide to Healthy Trees

Arborvitae (Thuja) are a popular coniferous tree with evergreen foliage that provides year-round privacy and beauty. To keep these trees healthy and thriving, proper fertilization is essential. Here's a detailed guide to fertilizing arborvitae in 50 easy steps:

Part 1: Assess Soil Conditions (Steps 1-10)

1. Dig a 6-inch hole near the base of the arborvitae.
2. Collect a soil sample from the hole.
3. Conduct a soil test to determine soil pH and nutrient levels.
4. Check the soil texture: sandy, clay, or loamy.
5. Observe existing vegetation and weed growth.
6. Identify any signs of nutrient deficiencies, such as yellow leaves or stunted growth.
7. Consider previous fertilizer applications and tree history.
8. Consult with a local nursery or arborist for recommendations.
9. Gather necessary materials, including slow-release fertilizer, gloves, and a spreader.
10. Determine the appropriate fertilization schedule based on soil conditions and tree age.

Part 2: Choose the Right Fertilizer (Steps 11-20)

11. Select a slow-release fertilizer with an NPK ratio of 10-10-10 or 12-4-8.
12. Choose a fertilizer specifically designed for evergreen trees.
13. Consider using an organic fertilizer such as compost or manure.
14. Avoid using high-nitrogen fertilizers, as they promote excessive growth and reduce disease resistance.
15. Calculate the amount of fertilizer needed based on tree size and soil conditions.
16. Divide the total amount by the number of applications planned.
17. Read and follow the manufacturer's instructions carefully.
18. Measure the fertilizer accurately using a scale or measuring cup.
19. Prepare a fertilizer solution by mixing the fertilizer with water, according to the manufacturer's instructions.
20. Allow the solution to sit for several hours or overnight.

Part 3: Fertilizing the Arborvitae (Steps 21-30)

21. Water the arborvitae thoroughly before fertilizing.
22. Create a 2- to 3-foot-wide ring around the base of the tree, leaving a 6-inch gap from the trunk.
23. Apply the fertilizer solution evenly within the ring.
24. Avoid applying fertilizer directly on the trunk or close to the base of the tree.
25. Spread the fertilizer as far as the drip line of the tree.
26. Water the arborvitae again after fertilizing to help the fertilizer reach the roots.
27. Fertilize new arborvitae trees once a month during the first growing season.
28. For established trees, fertilize twice a year: once in spring and once in fall.
29. Adjust the frequency and amount of fertilizer based on tree growth and soil conditions.
30. Monitor the arborvitae for signs of nutrient deficiency or excess.

Part 4: Fertilizing in Different Soil Conditions (Steps 31-40)

31. Sandy Soil: Use a slow-release fertilizer with a higher NPK ratio (e.g., 12-4-8) and apply more frequently (every 4-6 weeks).
32. Clay Soil: Amend the soil with compost or organic matter to improve drainage. Use a slow-release fertilizer with a lower NPK ratio (e.g., 10-10-10) and apply less frequently (every 6-8 weeks).
33. Loamy Soil: Use a balanced slow-release fertilizer (e.g., 10-10-10) and apply according to the recommended schedule.
34. Acidic Soil: Use an acidic fertilizer (e.g., ammonium sulfate) to lower the soil pH.
35. Alkaline Soil: Use an alkaline fertilizer (e.g., lime) to raise the soil pH.
36. Fertilizing Arborvitae in Containers: Use a slow-release fertilizer specifically designed for container plants. Apply according to the manufacturer's instructions.
37. Fertilizing Newly Planted Arborvitae: Water the tree thoroughly before and after fertilizing. Use a balanced slow-release fertilizer with a lower NPK ratio (e.g., 5-5-5).
38. Fertilizing Mature Arborvitae: Use a slow-release fertilizer with a higher NPK ratio (e.g., 12-4-8) to promote healthy growth and reduce disease.
39. Fertilizing in Winter: Avoid fertilizing in winter when the tree is dormant.
40. Nutrient Deficiency Symptoms: Yellowing leaves, stunted growth, brown needle tips.

Part 5: Other Considerations (Steps 41-50)

41. Avoid over-fertilizing, as it can damage the tree.
42. Water the arborvitae after fertilizing to help the fertilizer penetrate the soil.
43. Mulch around the arborvitae to retain moisture and suppress weeds.
44. Remove weeds from around the tree, as they compete for nutrients.
45. Inspect the arborvitae regularly for signs of pests or diseases.
46. Prune the arborvitae as needed to maintain its shape and promote air circulation.
47. Consult with a certified arborist for professional advice on fertilizing arborvitae.
48. Common Arborvitae Fertilizers: Miracle-Gro EverGreen, Scotts Evergreen Tree & Shrub Food, Osmocote Plus Evergreen & Conifer Fertilizer
49. Recommended Fertilizer Schedule: For established trees, fertilize once in spring (April-May) and once in fall (September-October).
50. Fertilizing Arborvitae for Specific Purposes: To promote growth, use a fertilizer with a higher nitrogen content. To enhance color, use a fertilizer with a higher potassium content. To improve disease resistance, use a fertilizer with a higher phosphorous content.

Tables

| Table 1: Soil pH Preferences of Arborvitae |
|---|---|
| Soil pH | Arborvitae Tolerance |
| 4.5-5.5 | Optimal |
| 5.5-6.5 | Tolerable |
| <4.5 or >6.5 | Not recommended |

| Table 2: Fertilizer NPK Ratios for Different Soil Types |
|---|---|
| Soil Type | NPK Ratio |
| Sandy | 12-4-8 |
| Clay | 10-10-10 |
| Loamy | 10-10-10 |

| Table 3: Common Nutrient Deficiencies in Arborvitae |
|---|---|
| Nutrient | Symptoms |
| Nitrogen | Yellowing leaves, stunted growth |
| Phosphorus | Brown needle tips, poor root development |
| Potassium | Weak stems, susceptibility to diseases |

| Table 4: Arborvitae Fertilization Schedule |
|---|---|
| Tree Age | Fertilization Frequency |
| New | Once a month |
| Established | Twice a year (spring and fall) |