Finding the Best Fertilizer for Healthy Leyland Cypress Trees

With their fast growth and stately evergreen foliage, Leyland cypress are prized for hedges, screens and specimen trees. To keep your Leyland cypress looking its best, occasional fertilization is recommended. But what is the best fertilizer to use on these handsome conifers?

Overview of Leyland Cypress Trees

Native to western North America, Leyland cypress (×Cupressocyparis leylandii) is a popular landscape conifer in many regions Key facts

• A hybrid between Alaskan cedar and Monterey cypress. Also called Leylandii.

• Fast growing to around 40-60 feet high and 10-20 feet wide.

• Retains a neat, pyramidal to columnar shape. Makes a dense, screening hedge.

• Feathery, fine-textured foliage ranges from bright to dark green.

• Hardy in USDA zones 6-10. Tolerates most soil types.

• Does well with full sun exposure. Needs well-drained soil.

• Long lifespan of around 60 years. Low maintenance once established.

How Often to Fertilize Leyland Cypress

Leyland cypress trees do not require heavy feeding. But light fertilization every 2-3 years will promote healthy growth.

• Young trees up to 5 years old have higher nutrient needs during establishment. Fertilize annually in spring.

• Mature trees can be fertilized every 2-3 years to maintain vigor and deep green foliage.

• Avoid over-fertilizing, which causes overly fast growth prone to storm damage.

• Leyland cypress may not need any fertilizer if planted in rich, fertile soil. Monitor growth to determine needs.

• Where nutrient deficient, chlorosis causes yellowing foliage. Fertilize to restore green color.

• In very poor soils, a light spring feed each year may be warranted.

Selecting the Best Fertilizer for Leyland Cypress

When choosing a fertilizer for Leyland cypress, keep these tips in mind:

• Slow release formula – Look for slow release or controlled release fertilizer that provides a gradual nutrient supply over 8-9 months.

• Balanced NPK – Pick a balanced fertilizer with near equal N-P-K values like 10-10-10. Avoid high nitrogen products.

• Acidic reaction – Select an acidic fertilizer as Leyland cypress prefers slightly acidic soil with a pH of 5-6.

• Micronutrients – Choose a product containing essential micronutrients like magnesium, iron, manganese and zinc.

• Organic or synthetic – Both organic and synthetic fertilizers can work well. Organic options include compost, manure, cottonseed meal.

• Fertilizer for acid loving plants – Use fertilizers formulated specifically for azaleas, rhododendrons, camellias and other acid lovers.

5 Best Fertilizers for Leyland Cypress Trees

1. Espoma Tree-tone

• Organic granular fertilizer made for acid-loving trees like cypress.

• Balanced NPK of 6-4-4 plus iron and magnesium.

• Coated slow release pellets last for 3-4 months.

• Use 2-3 lbs per tree, depending on size.

2. Miracle-Gro Shake ‘N Feed

• Popular synthetic fertilizer for trees, shrubs and acid-lovers.

• 40% slow release nitrogen plus micronutrients.

• NPK ratio of 15-30-15. Just shake over root zone.

• Use 1 lb per inch of trunk diameter.

3. Jobe’s Organic Tree Fertilizer Spikes

• Organic nutrient spikes made from poultry litter, bone and feather meal.

• NPK of 9-6-3 plus minors for full nutrition.

• Insert into root zone and they slowly release nutrients.

• Use 10 spikes per mature tree.

4. Grow More Seaweed Extract

• Concentrated liquid kelp extract for soil drench or foliar feed.

• Packed with 70+ micro-nutrients, amino acids and growth hormones.

• Use as supplemental fertilizer to build plant health.

• Dilute 4 Tbsp per gallon of water and apply.

5. Down To Earth Acid Mix Fertilizer

• Dry organic fertilizer blend for acid loving conifers.

• Balanced NPK of 6-3-3 with sulfur and iron.

• Mix into soil around drip zone in early spring.

• Use 1 lb per young tree, up to 10 lbs for mature trees.

How to Apply Fertilizer to Leyland Cypress

Follow these tips for most effective fertilizer application:

• Apply fertilizer in early spring as new growth emerges.

• Spread granular fertilizer evenly around the tree from the trunk to beneath the outer foliage.

• For liquid feeds, mix according to label and water into the root zone.

• Place stakes or spikes into the soil evenly spaced beneath the branches.

• Follow fertilizer application with deep watering to aid nutrient absorption by roots.

• Reapply controlled release fertilizer around mid-summer if needed.

• Always avoid placing fertilizer directly on foliage or against the trunk.

Signs of Over-Fertilizing Leyland Cypress

Too much fertilizer can damage Leyland cypress trees. Look for these symptoms:

• Scorched, yellowing or browning foliage

• Stunted leaf and shoot growth

• White crusting on surface of soil

• Potassium and phosphorus deficiencies as nitrogen dominates

• Accumulation of excess soluble salts around roots

• Root system damage from fertilizer burn

Correcting Over-Fertilization

If over-fertilization of Leyland cypress occurs, take these corrective steps:

• Immediately stop fertilizing and flush soil with water to remove salts.

• Remove any built-up fertilizer crusts from soil surface.

• Apply gypsum to improve drainage and leach out excess nutrients.

• Monitor soil pH – overuse of acidic fertilizers lowers pH excessively.

• Let trees recover before fertilizing again at much lower dosage.

• Replace damaged trees if root systems have been severely burned.

To keep your Leyland cypress hedge or specimen trees looking their best, fertilization every 2-3 years is recommended. A quality slow release fertilizer applied in early spring will provide steady nutrition without risk of overfeeding. Tailor the fertilizer choice and dosage to the plant’s age and observed condition for a healthy, vibrant Leyland cypress display.