Choosing the best fertilizer for weeping willow tree growth requires more than selecting a fertilizer with the highest nitrogen percentage. A productive feeding program must account for the tree’s rapid growth rate, soil fertility, moisture availability, root-zone conditions, and whether the tree actually has a nutrient deficiency.

Weeping willow (Salix babylonica) is a fast-growing deciduous tree that naturally performs best where adequate moisture and nutrients are available. Nitrogen supports chlorophyll production and vigorous shoot development, phosphorus contributes to energy transfer and root processes, while potassium helps regulate water relations and supports overall plant function.

For established trees, a slow-release fertilizer can provide a steadier nutrient supply than a concentrated soluble fertilizer. Espoma specifically lists willow among the trees recommended for Tree-tone, while its current 6-3-2 analysis combines organic nutrient sources with slow-release nitrogen, humic acids, and beneficial microbes.

In this guide , we review 10 of the best fertilizers for weeping willow trees, including organic granular fertilizers, fertilizer spikes, controlled-release products, and complete tree fertilizers. Each product is evaluated for its NPK ratio, nutrient-release characteristics, application method, root-zone suitability, and usefulness for different weeping willow growing conditions.

10 Best Fertilizer For Weeping Willow Tree 2026

1. Espoma Organic Tree-tone 6-3-2 – Best Overall Fertilizer For Weeping Willow Tree

The Espoma Organic Tree-tone 6-3-2 is the strongest overall choice for gardeners looking for a fertilizer specifically suited to ornamental and shade trees. Espoma lists willow among the trees for which Tree-tone can be used, making it particularly relevant to Salix babylonica. Its 6-3-2 analysis supplies nitrogen, available phosphate, and soluble potash while also providing calcium and magnesium.

The formulation contains 3.6% slow-release nitrogen, which is useful for a fast-growing willow because nutrients are released more gradually rather than being supplied entirely in immediately soluble form. It also contains humic acids and beneficial microorganisms, while the manufacturer identifies feather meal, poultry manure, bone meal, alfalfa meal, greensand, sulfate of potash, and sulfate of potash magnesia among its nutrient sources. This makes Tree-tone substantially different from a basic high-nitrogen lawn fertilizer.

Espoma recommends feeding established trees in early spring before growth starts and again in fall after leaf drop but before the ground freezes. For smaller trees, the fertilizer can be distributed around the root spread, while larger trees can be treated with holes under the dripline according to the manufacturer’s directions.

Pros:

• 6-3-2 NPK
• Slow-release nitrogen
• Organic ingredients
• Contains humic acids
• Beneficial microbes
• Willow approved
• Multiple sizes

Cons:

• Strong organic odor
• Requires watering
• Larger trees need more

Why It Is A Top Pick

Espoma Tree-tone is the most directly targeted option because the manufacturer specifically identifies willow among its recommended trees. Its moderate 6-3-2 analysis also avoids the extremely high nitrogen concentration found in some tree-feeding products, making it a strong choice for regular nutritional maintenance when fertilizer is actually required.

2. Jobe’s Tree & Shrub Fertilizer Spikes 15-3-3 – Best Fertilizer Spikes For Weeping Willow

Jobe’s Tree & Shrub Fertilizer Spikes provide a convenient alternative to spreading granular fertilizer beneath a large weeping willow. The tree-and-shrub formulation is reported as 15-3-3, giving the product a nitrogen-forward analysis designed to provide continuous nutrition below the soil surface. The pre-measured spike format eliminates the need to mix fertilizer or calculate individual applications of loose granules.

The 15% nitrogen content can be useful where a willow has reduced vegetative growth caused by inadequate nitrogen availability. The 3% phosphate supports energy-transfer and root processes, while the 3% potash contributes to general plant function and water regulation. Because the formula is concentrated, however, it should be applied strictly according to the package directions rather than used to force faster growth.

The spikes are placed around the tree’s root zone rather than directly beside the trunk. Their below-surface placement is useful where runoff from surface-applied fertilizer is a concern, although correct spacing remains important because concentrating fertilizer in too few locations can create localized nutrient concentrations. Jobe’s tree-and-shrub spikes are particularly practical for gardeners who prefer a simple hammer-in feeding system.

Pros:

• 15-3-3 NPK
• Pre-measured spikes
• Root-zone feeding
• No mixing
• Easy application
• Slow-release feeding
• Less surface runoff

Cons:

• Concentrated nitrogen
• Limited placement area
• Hard soil problem

Best Use

Choose Jobe’s Tree & Shrub spikes when convenience and targeted root-zone feeding matter more than spreading granular fertilizer across a very large root system.

3. Osmocote Plus Smart-Release 15-9-12 – Best Slow-Release Fertilizer For Weeping Willow

Osmocote Plus 15-9-12 is a controlled-release fertilizer designed to provide a steady nutrient supply throughout the growing cycle. The manufacturer identifies it for landscaping and foliage production, and the analysis supplies 15% nitrogen, 9% phosphate, and 12% potash. It also contains magnesium, sulfur, boron, iron, manganese, molybdenum, and zinc.

The higher nitrogen level can support vigorous foliage and shoot development when nitrogen availability is limiting, while the potassium content is useful for general physiological functions and water regulation. Unlike a simple soluble fertilizer, Osmocote’s coated granules release nutrients according to its controlled-release technology. Depending on the specific formulation and temperature, release longevity varies, so the exact product label should be followed.

This fertilizer is especially interesting for gardeners who want consistent nutrient availability without repeated liquid feeding. It should be distributed evenly through the appropriate root zone rather than piled against the trunk, and irrigation after application helps move released nutrients into the soil. For a mature willow, soil testing remains important before repeatedly applying a complete fertilizer containing substantial phosphorus.

Pros:

• 15-9-12 NPK
• Controlled release
• Broad micronutrients
• Magnesium included
• Sulfur included
• Landscape compatible
• Consistent feeding

Cons:

• Higher phosphorus
• More expensive
• Rate sensitive

Best Use

Osmocote Plus is best for gardeners who want controlled-release nutrition and a broad nutrient package rather than a strictly organic fertilizer.

4. Miracle-Gro Tree & Shrub Plant Food Spikes 15-5-10 – Best Fertilizer Spikes For Large Weeping Willow

Miracle-Gro Tree & Shrub Plant Food Spikes are designed to deliver nutrition beneath the soil around trees and shrubs. The 15-5-10 analysis places considerable emphasis on nitrogen while still providing phosphorus and potassium. This makes the formulation appropriate for gardeners looking for a convenient fertilizer for established woody plants when additional nutrition is necessary.

The nitrogen component can support leaf production and shoot growth, which are particularly important characteristics for a fast-growing weeping willow. Phosphorus contributes to cellular energy-transfer processes, while potassium participates in water regulation and enzyme activity. Because willow naturally produces substantial vegetative growth, applying more fertilizer than necessary is not a reliable way to produce a healthier tree.

The spike format eliminates measuring and mixing, which can be useful beneath a broad willow canopy. Position the spikes around the root zone according to the product directions instead of concentrating them near the trunk. This makes the product particularly convenient for homeowners who prefer a low-mess feeding method.

Pros:

• 15-5-10 NPK
• Pre-measured spikes
• Easy application
• Tree-specific formula
• Slow-release feeding
• No mixing
• Low mess

Cons:

• High nitrogen
• Placement matters
• Not deficiency specific

Best Use

This is a practical choice for homeowners who want a simple tree-feeding system without measuring loose fertilizer beneath a large canopy.

5. Jobe’s Evergreen & Tree Fertilizer Spikes 13-3-4 – Best Root Feeding Fertilizer For Weeping Willow

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Jobe’s 01611 fertilizer spikes provide a 13-3-4 analysis in a pre-measured spike format. The product is marketed for evergreen and tree applications and is designed to deliver nutrients below the soil surface. Its 13% nitrogen concentration makes it a foliage-oriented fertilizer for trees requiring additional vegetative nutrition.

The 13-3-4 ratio provides more nitrogen than phosphorus or potassium, making it more appropriate for a willow showing reduced growth than a willow already producing abundant green foliage. Potassium contributes to water regulation and physiological processes, while phosphorus is involved in energy transfer and root development. The formulation should not be treated as a universal solution for yellowing leaves because chlorosis can also result from water stress, root problems, pH issues, or micronutrient deficiencies.

The spike format is useful for targeted root feeding around the dripline. Pre-measured fertilizer reduces the need for handling loose granules, although the tree’s size and the manufacturer’s recommended number and spacing of spikes should determine the application. Soil should be sufficiently workable before installation to avoid damaging the spike or surrounding roots.

Pros:

• 13-3-4 NPK
• Pre-measured feeding
• Root-zone placement
• Easy installation
• Nitrogen focused
• Minimal runoff
• No mixing

Cons:

• Evergreen focused
• Limited distribution
• Needs soft soil

Best Use

Use these spikes when targeted below-surface feeding is preferred and the willow requires additional nitrogen rather than a broad soil amendment.

6. Dr. Earth Natural Wonder Tree & Shrub Fertilizer – Best Organic Fertilizer For Weeping Willow

Dr. Earth Natural Wonder Tree & Shrub fertilizer is an option for gardeners who prefer natural nutrient sources for landscape trees and shrubs. Organic-oriented fertilizers release nutrients as their components break down through biological activity, providing a different feeding pattern from highly soluble synthetic fertilizers. This approach can work well as part of a broader soil-management program.

For weeping willow, organic nutrition should be combined with adequate moisture because nutrient availability and root uptake depend heavily on soil-water conditions. The tree’s preference for moist growing conditions means a fertilizer application will not correct chronic drought stress. Likewise, fertilizer should not be used to compensate for compacted soil, root damage, or drainage problems.

Apply the product according to the current label and distribute it across the appropriate root zone. Keep fertilizer away from direct contact with the trunk and water after application when rainfall is insufficient. This makes the product more appropriate for gardeners who prioritize gradual organic nutrition over rapid soluble feeding.

Pros:

• Organic approach
• Tree formulation
• Gradual feeding
• Soil focused
• Natural ingredients
• Easy granules
• Landscape use

Cons:

• Slower response
• Odor possible
• Rate dependent

Best Use

Dr. Earth is best suited to gardeners who want an organic-oriented tree fertilizer that can be incorporated into a broader soil-building program.

7. Down To Earth Tree & Shrub Fertilizer 4-2-4 – Best Granular Fertilizer For Weeping Willow

Down To Earth Tree & Shrub Fertilizer is a granular product intended for woody landscape plants and provides a moderate nutrient profile rather than an extremely concentrated nitrogen formulation. Its lower-analysis approach can be useful where gardeners want to supplement soil fertility without relying on a very high nitrogen dose. Granular fertilizer also makes it possible to distribute nutrients across a wider root-zone area than individual spikes.

A moderate fertilizer can be particularly useful for established willows that need maintenance nutrition rather than aggressive growth stimulation. Nitrogen supports leaf and shoot development, phosphorus contributes to energy metabolism, and potassium supports water relations and general plant function. The exact analysis should always be checked against the current package because product formulations can change.

Spread granular fertilizer evenly across the root zone and avoid placing concentrated piles next to the trunk. Water thoroughly after application so nutrients can move into the soil where roots can access them. The broad distribution pattern is an advantage when treating a large tree with an extensive root system.

Pros:

• Granular formulation
• Tree focused
• Moderate analysis
• Broad root coverage
• Easy spreading
• Soil application
• Flexible feeding

Cons:

• Slower response
• Requires measuring
• Formula varies

Best Use

This product is better suited to gardeners who prefer granular feeding across the willow’s root zone rather than concentrated fertilizer spikes.

8. Ferti-Lome Tree & Shrub Food – Best High-Nitrogen Fertilizer For Weeping Willow

Ferti-Lome Tree & Shrub Food is designed for woody landscape plants and provides a more concentrated nutrient source than many organic tree fertilizers. A nitrogen-oriented tree fertilizer can be useful for a weeping willow with documented nitrogen deficiency and weak vegetative growth. It is not necessary simply because the tree is young or because the owner wants maximum annual growth.

Nitrogen is the principal nutrient associated with chlorophyll production and vegetative development, making adequate nitrogen particularly important for a willow’s large leafy canopy. However, excessive nitrogen can create overly vigorous growth and increase fertilizer waste. The correct application rate should therefore be based on the product label, soil conditions, tree size, and evidence of nutritional need.

Granular tree fertilizer should be spread throughout the root zone rather than placed directly against the trunk. Irrigation after application helps nutrients enter the soil solution and reduces the risk of concentrated fertilizer remaining on the soil surface. For established willows, avoid applying additional fertilizer when growth and foliage are already vigorous.

Pros:

• Tree-specific formula
• Nitrogen focused
• Granular application
• Broad coverage
• Easy measuring
• Supports foliage
• Landscape compatible

Cons:

• Overfeeding risk
• Requires irrigation
• Soil test preferred

Best Use

Ferti-Lome is most appropriate where a weeping willow needs a stronger nutritional boost and nitrogen availability is known to be limiting.

9. Miracle-Gro Shake ‘N Feed All Purpose Plant Food 12-4-8 – Best General Fertilizer For Weeping Willow

A balanced or moderately nitrogen-forward general fertilizer can be useful when a dedicated tree fertilizer is unavailable and the soil requires supplemental macronutrients. A 12-4-8 analysis provides a 3-1-2 relationship between nitrogen, phosphate, and potash, a ratio that is commonly considered suitable for woody plants when all three nutrients are needed. The important qualification is that fertilizer should be matched to soil requirements rather than applied automatically.

The 12% nitrogen supports foliage and shoot production without reaching the concentration of some high-nitrogen tree spikes. The 4% phosphate contributes to energy-transfer and root functions, while the 8% potash supplies potassium for water regulation and plant physiological processes. This ratio can therefore be useful as a general-purpose complete fertilizer for a willow when soil testing supports the use of a complete NPK product.

Apply the fertilizer evenly around the tree’s active root zone and keep the granules away from the trunk. Water thoroughly after application and avoid combining the product with another complete fertilizer unless the total nutrient rate has been calculated. For mature willows, a soil test is the best way to determine whether phosphorus and potassium should be added.

Pros:

• 12-4-8 ratio
• 3-1-2 relationship
• Moderate nitrogen
• Easy application
• Broad availability
• General purpose
• Granular feeding

Cons:

• Not tree specific
• Phosphorus may be unnecessary
• Rate sensitive

Best Use

Choose this option when you need a general complete fertilizer with a 3-1-2 nutrient relationship and do not require a specialized organic tree formulation.

10. 10-10-10 All-Purpose Fertilizer – Best Balanced Fertilizer For Weeping Willow Tree

A quality 10-10-10 fertilizer is one of the simplest complete fertilizer choices for gardeners who want equal percentages of nitrogen, phosphate, and potash. The formulation supplies 10% of each primary nutrient by weight and is widely available in granular form. It is best considered a soil-test-driven option rather than an automatic annual fertilizer for every weeping willow.

The equal NPK ratio can be useful when soil analysis indicates that nitrogen, phosphorus, and potassium are all below desirable levels. Nitrogen supports the willow’s foliage and shoots, phosphorus contributes to energy-transfer reactions and root processes, while potassium supports water regulation and overall physiological performance. If phosphorus and potassium are already adequate, however, a balanced fertilizer may supply nutrients the tree does not need.

The granular material should be distributed across the root zone instead of being concentrated around the trunk. Apply according to the manufacturer’s recommended rate and water the area thoroughly after feeding. Because mature willows can develop large root systems, uniform distribution is more useful than placing a large quantity of fertilizer in one small area.

Pros:

• Balanced NPK
• Widely available
• Simple formula
• Easy measuring
• Broad coverage
• Cost effective
• Versatile use

Cons:

• May overfeed
• Phosphorus accumulation
• Soil test needed

Best Use

10-10-10 is best when soil testing indicates that a weeping willow needs nitrogen, phosphorus, and potassium together rather than nitrogen alone.

Buyer’s Guide: Choosing Fertilizer For Weeping Willow Tree

Consider The NPK Ratio

The first specification to examine is the NPK analysis printed on the fertilizer bag. A weeping willow generally needs nitrogen for vigorous foliage production, phosphorus for energy-transfer processes, and potassium for water regulation and general physiological functions.

A ratio around 3-1-2 can be particularly useful when all three macronutrients are required. Products such as 12-4-8 and 18-6-12 follow this relationship, while Espoma Tree-tone uses a lower 6-3-2 analysis with a substantial slow-release nitrogen component.

Choose Slow-Release Fertilizer

Slow-release fertilizer is usually preferable when a willow needs supplemental nutrition because nutrients are released over a longer period. This reduces the likelihood of supplying a large concentration of soluble nutrients all at once.

Espoma’s Tree-tone, for example, contains 3.6% slow-release nitrogen within its 6-3-2 analysis.

Test The Soil First

Do not assume that yellow leaves automatically indicate nitrogen deficiency. Yellowing can also be caused by drought, waterlogging, root damage, unsuitable soil pH, iron deficiency, pests, disease, or other environmental problems.

A soil test provides a much better basis for deciding whether nitrogen, phosphorus, potassium, or another nutrient should be applied. This is particularly important for mature trees because unnecessary fertilizer provides little benefit while increasing the amount of nutrients introduced into the soil.

Consider The Tree’s Age

Young weeping willows may require closer nutritional management while establishing their root and shoot systems. Established trees growing vigorously may require little supplemental fertilizer if the soil already provides sufficient nutrients.

A mature willow producing long new shoots and dense green foliage is not necessarily improved by additional nitrogen. Fertilizer should correct a nutritional limitation rather than simply maximize vegetative growth.

Apply Fertilizer Around The Root Zone

Do not pile fertilizer against the trunk. The active roots of a large tree extend throughout a broad area, so distributing fertilizer around the appropriate root zone is generally more useful than concentrating it immediately around the base.

Espoma’s Tree-tone directions specifically recommend applying fertilizer around the root spread for small trees and using holes under the dripline for large trees.

Maintain Adequate Moisture

Weeping willow is naturally associated with moist growing conditions, so fertilizer cannot substitute for water. A nutrient-rich soil that remains chronically dry can still produce a stressed tree.

Water the root zone appropriately and maintain a suitable mulch layer without piling mulch against the trunk. Good moisture management improves the tree’s ability to absorb nutrients already present in the soil.

Avoid Excessive Nitrogen

High nitrogen can produce rapid shoot and foliage development, but excessive vegetative growth is not always desirable. The objective should be healthy, structurally sound growth rather than simply maximizing the amount of new foliage.

This is why a moderate slow-release product such as Tree-tone can be preferable to repeatedly applying concentrated nitrogen fertilizer. The right fertilizer is the one that corrects the actual limitation.

Best Fertilizer For Weeping Willow Tree FAQs

1. What is the best fertilizer for a weeping willow tree?

Espoma Organic Tree-tone 6-3-2 is the best overall choice in this comparison because it is specifically recommended by Espoma for willow and provides slow-release nutrition, humic acids, and beneficial microbes.

2. What NPK ratio is best for weeping willow?

A ratio around 3-1-2 is a useful option when the soil requires all three major nutrients. A 12-4-8 or 18-6-12 fertilizer provides this general relationship, although a soil test should determine whether a complete fertilizer is actually necessary.

3. Does weeping willow need fertilizer every year?

Not necessarily. A healthy mature weeping willow growing vigorously in fertile soil may require little or no supplemental fertilizer.

4. When should I fertilize my weeping willow?

Early spring is an appropriate feeding period when fertilizer is required because the tree is beginning active growth. Espoma also recommends a fall feeding after leaf drop but before the ground freezes for its Tree-tone product.

5. Can I use 10-10-10 fertilizer on a weeping willow?

Yes, provided the soil requires nitrogen, phosphorus, and potassium. A 10-10-10 fertilizer should not be applied automatically when phosphorus and potassium are already adequate.

6. Is organic fertilizer good for weeping willow?

Yes. Organic fertilizers can provide gradual nutrient release and contribute organic materials to the soil, although they should still be used according to the tree’s actual nutritional requirements.

7. Can you over-fertilize a weeping willow?

Yes. Excess fertilizer can create excessive vegetative growth, increase soluble salts, waste nutrients, and potentially stress the root system. Applying fertilizer according to soil-test results and label rates is safer than attempting to force rapid growth.

Conclusion

In conclusion, the best fertilizer for weeping willow tree should provide appropriate nutrition without forcing unnecessarily rapid growth. The tree’s moisture availability, soil fertility, age, and actual nutrient requirements should determine the fertilizer program.

Espoma Organic Tree-tone 6-3-2 is the best overall choice because it is specifically recommended for willow, contains slow-release nitrogen, and combines organic nutrient sources with humic acids and beneficial microbes. Osmocote Plus 15-9-12 is the runner-up for gardeners who prefer controlled-release granular nutrition with a broader micronutrient package.

For convenience, fertilizer spikes such as Jobe’s Tree & Shrub 15-3-3 and Miracle-Gro Tree & Shrub 15-5-10 make targeted root-zone feeding easier. Granular 12-4-8 and 10-10-10 fertilizers are useful alternatives when soil testing indicates that a complete NPK fertilizer is appropriate.

The most important factor is matching fertilizer to the tree rather than choosing the strongest product available. Maintain consistent moisture, distribute fertilizer across the root zone, avoid piling nutrients against the trunk, and use soil testing whenever possible to build a precise nutrition program for Salix babylonica.