Best Organic Fertilizer For Crape Myrtles: Compare 9 Options

#1 · Best Overall

1. Espoma Plant-Tone

• Form: Granules
• Weight: 4 lb

Best for: Organic feed for mixed landscapes.

Why it ranks #1: Its natural and organic formula is listed for trees and shrubs, and the directions specifically recommend spring and fall use on those plants.

A slow-release reservoir of nutrients gives Espoma Plant-Tone a practical role in gardens where crape myrtles share space with flowers, vegetables, trees, and shrubs. This all-purpose organic granular fertilizer is not limited to one ornamental, so one product can serve several plant groups across the landscape.

Plant-Tone’s natural organics break down slowly, providing a longer-lasting nutrient reservoir rather than a liquid feeding format. Its stated use across flowers, vegetables, trees, and shrubs makes it suitable for a mixed garden that includes crape myrtles. The directions identify spring and fall as the best times to use it on trees and shrubs, which gives those plantings a seasonal routine. Granules require handling and application to soil, and protective equipment is advised.

Skip it if you need a liquid product focused specifically on crape-myrtle blooms; TPS Nutrients Crepe Myrtle Fertilizer is the more targeted option.

Choose Plant-Tone when crape myrtles are part of a varied planting of trees, shrubs, flowers, or vegetables and seasonal granule applications suit your routine. Its broad-use formula is less narrowly focused than a crape-myrtle-specific fertilizer.

Listed on Amazon as: Espoma Organic Plant-Tone 5-3-3 Natural & Organic All Purpose Plant Food; 4 lb. Bag; The Original Organic Fertilizer for All Flowers, Vegetables, Trees, and Shrubs.

#2 · Best Tree Formula

2. Old Cobblers Farm Wicked Organics

• Form: Granules
• Weight: 5 lb

Best for: Slow-release feed for woody plantings.

Why it ranks #2: This organic 4-3-3 poultry-litter fertilizer is specifically intended for trees, shrubs, and perennials, with a slow-release formulation.

A single-ingredient poultry-litter formula with a 4-3-3 ratio gives Wicked Organics a clear focus on trees, shrubs, and perennials. Its slow-release granular format is aimed at the woody and perennial backbone of a garden, including flowering shrubs and specimen trees such as crape myrtles.

The listed nutrient balance is described as supplying nitrogen for foliage and flowering, phosphorus for roots, and potassium for resilience, connecting the 4-3-3 ratio to several plant needs. Slow-release granules suit gardeners seeking a feed for established woody plantings rather than a liquid application. Natural calcium is also named in the title and product description. The listing does not provide an application schedule, so buyers will need to follow product directions for timing and amount.

Skip it if you need a stated seasonal schedule for trees and shrubs; Espoma Plant-Tone lists spring and fall use guidance for those plantings.

This suits gardeners feeding crape myrtles as part of established trees, shrubs, and perennial beds who prefer slow-release granules. Its woody-plant focus is clear, but the supplied facts leave timing and application amounts unspecified.

Listed on Amazon as: Old Cobblers Farm Wicked Organics 4-3-3 Fertilizer – Tree, Shrub & Perennial, Organic Slow-Release Poultry-Litter Plant Food with Natural Calcium (5 lbs | 10 lbs | 15 lbs | 20 lbs), 5 lbs

#3 · Best Balanced Blend

3. GreenGro All Purpose 5-5-5

• Form: Powder
• Weight: 4 lb

Best for: Balanced organic feed for mixed beds.

Why it ranks #3: Its OMRI-listed 5-5-5 formula uses ten organic ingredients and is described for trees and shrubs as well as other garden plants.

A balanced 5-5-5 blend from ten listed organic ingredients makes GreenGro All Purpose a versatile option for gardeners feeding crape myrtles alongside other plants. The product is described for trees, shrubs, vegetables, houseplants, annuals, and perennials, allowing one formula to cover varied garden areas.

The ingredient blend includes meals, kelp, volcanic ash, and mineral sources, with the listing identifying balanced NPK, trace minerals, and sulfur. That broad composition and use across trees and shrubs can suit a landscape containing crape myrtles as well as other plantings. The powder form is a dry application format, rather than a liquid feed. Protective gear is advised during handling, so users should account for that step when applying it.

Skip it if you want a fertilizer with a stated crape-myrtle-specific formula; Natures Wisdom Crepe Myrtle Tree fertilizer is tailored to that plant.

GreenGro fits gardeners who want a broadly applicable organic powder for crape myrtles within a mixed landscape. Its 5-5-5 blend and broad plant list are useful for shared garden use, while handling precautions remain part of application.

Listed on Amazon as: GreenGro All Purpose Organic Fertilizer 5-5-5, 4 lb

#4 · Best Slow-Release

4. Organic Plant Magic Granules

• Form: Granules
• Weight: 4 lb

Best for: Monthly granules for varied gardens.

Why it ranks #4: The listing describes these granules as truly organic and slow-release, with monthly application suggested for a broad range of outdoor plants.

Hand-spreadable granules that can also go into planting holes make Organic Plant Magic adaptable to different garden tasks. The product is presented as a slow-release, all-purpose fertilizer for indoor and outdoor plants, including shrubs and fruit trees, so it can serve crape myrtles within a broader planting mix.

The application choices—adding granules to planting holes, mixing them with soil, or top-dressing by hand or spreader—let gardeners work them into new plantings or established beds. The listing says to sprinkle granules onto soil monthly or more and water as normal, offering a recurring routine rather than a one-time application. Its indoor-and-outdoor, all-purpose scope covers shrubs and trees, though the supplied facts do not identify a crape-myrtle-specific nutrient blend.

Skip it if you want a fertilizer formulated specifically for crape myrtles; TPS Nutrients Crepe Myrtle Fertilizer names that tree as its focus.

This is a fit for gardeners who want one granular product for mixed indoor and outdoor plantings and value several application methods. For crape myrtles, its broad-use positioning is the boundary: no specific formulation for that tree is stated.

Listed on Amazon as: Organic Plant Magic – Truly OrganicTM Slow Release Granular Fertilizer : Long-Lasting Plant Food Granules – Indoor & Outdoor Flowers, Vegetable Gardens, Fruit Trees, Shrubs, House Plants [One 4 lb Bag]

#5 · Best Mycorrhizae Blend

5. SUPERthrive Organic 4-4-4

• Form: Granules
• Weight: 8.7 lb

Best for: Organic granular feed with mycorrhizae.

Why it ranks #5: This granular organic 4-4-4 formula includes mycorrhizae and is listed for trees and shrubs, though the supplied details do not target crape myrtles.

Mycorrhizae that help expand root surface area distinguish SUPERthrive Organic 4-4-4 from a basic all-purpose granular feed. The listing connects that feature to improved nutrient and water uptake, and names trees and shrubs among its uses, making crape myrtles an eligible part of a broader garden plan.

This 100% organic granular fertilizer supplies the listed 4-4-4 macro-nutrient balance for use throughout the growing season. Mycorrhizae are included to expand root surface area, which the product says helps plants take up water and nutrients. The stated uses include flowers, vegetables, houseplants, bonsai, trees, and shrubs, allowing the same product to cover mixed plantings. The bundle contains three 2.2-pound units, a multi-pack format that requires storage for remaining granules.

Skip it if you want a fertilizer specifically formulated for crape myrtles; TPS Nutrients Crepe Myrtle Fertilizer is explicitly focused on that tree.

This is a fit for gardeners seeking organic granules with mycorrhizae for a mixed planting that includes trees or shrubs. Its broad all-purpose scope is the boundary; the listing does not specify a crape-myrtle-specific formulation.

Listed on Amazon as: SUPERthrive Organic All-Purpose Fertilizer, 4-4-4, 2.2 lbs, 3-Pack

#6

6. Neptune's Harvest Kelp Meal

• Form: Powder

Best for: Kelp meal for soil enrichment.

Why it ranks #6: Its organic kelp meal adds organic matter and trace minerals, but its 1-0-2 analysis and general-use description are less tree-specific.

Made from Ascophyllum nodosum Norwegian kelp, Neptune’s Harvest Kelp Meal brings organic matter, trace minerals, and nutrients to soil as a dry plant food. Its broad indoor-and-outdoor listing includes flowers and gardens, making it an option for crape myrtles within a wider planting scheme.

The product is a powder derived from kelp, and the supplied composition lists organic matter, ash minerals, moisture, and plant nutrients. That soil-enrichment positioning may suit gardeners who want a multi-purpose feed for flowers, vegetables, lawns, and other plants rather than a crape-myrtle-specific formula. The 12-pound resealable bag supports storage between uses, while the listing gives no crape-myrtle application rate. Its stated nutrient analysis is relatively low in nitrogen compared with the other named nutrients.

Skip it if you want a formula specifically optimized for crape myrtles; Natures Wisdom Crepe Myrtle Tree fertilizer names that use directly.

Kelp Meal suits gardeners looking for a multi-purpose soil amendment and plant food for mixed gardens that include flowering plants. It is not presented as a crape-myrtle-specific feed, so consider that distinction when choosing it for this tree.

Listed on Amazon as: Neptune’s Harvest Organic Kelp Meal Plant Food (1-0-2) – 12 lb Resealable Bag – Multi-Purpose Seaweed Fertilizer – Indoor & Outdoor Plant Fertilizer for Lawns, Gardens, Vegetables & Bulbs

#7

7. TPS Nutrients Crepe Myrtle Liquid

• Form: Liquid
• Weight: 0.32 kg

Best for: Liquid feed for flowering crape myrtles.

Why it ranks #7: It directly targets crape myrtles and supports blooms, foliage, and roots, but the supplied listing does not identify it as organic.

Liquid plant food focused on crape myrtles makes this an easy-to-target option for gardeners prioritizing blooms alongside tree development. TPS Nutrients says it supports abundant, colorful flowering, fresh leaf and stem growth, and healthy roots, giving landscape trees nutritional support across more than one part of their growth.

The liquid form suits gardeners who prefer a plant food that is not a dry granular top-dressing. Its crape-myrtle focus keeps the product aligned with the tree in this roundup, while the listed support for roots, leaves, stems, and blooms addresses several growth goals. Root development is linked to better water and nutrient uptake, and fresh leaf and stem development supports a fuller tree. The supplied information does not specify a dilution rate or application schedule.

Skip it if you want a stated application schedule or prefer slow-release granules; Espoma Plant-Tone is a granular alternative for trees and shrubs.

A crape-myrtle owner seeking liquid nutrition for blooms, roots, and fresh growth may appreciate this focused formula. It also suits outdoor landscape trees; check the product directions for application details, which are not included in the supplied facts.

Listed on Amazon as: Crepe Myrtle Fertilizer, Liquid Plant Food for Long-Lasting Blooms, 8 oz

#8

8. Natures Wisdom Crepe Myrtle Food

• Form: Powder
• Weight: 1.7 lb

Best for: Water-soluble feed for flowering trees.

Why it ranks #8: This powder is specifically formulated for crape myrtles, but its listed phosphate and sulfate ingredients do not establish an organic formulation.

A crape-myrtle-focused 8-55-7 nutrient blend gives Natures Wisdom a defined role for gardeners feeding flowering trees and ornamentals. The powder dissolves for water-based application, and the product also lists shrubs and vines, making its stated use broader than crape myrtles alone.

The formula is specifically described as optimized for crepe myrtles, linking its nutrient blend to the tree’s bloom and foliage needs. Its water-soluble powder form supports mixing for application, while the included measuring scoop provides a way to portion the product. The listed range also includes flowering trees, shrubs, vines, and named ornamentals, so it can suit a mixed planting. The supplied directions are incomplete, so a full mixing rate cannot be established from these facts.

Skip it if you prefer a ready-to-apply granular feed and do not want to mix powder; Old Cobblers Farm Wicked Organics is a granular tree-and-shrub option.

Gardeners prioritizing a crape-myrtle-focused, water-soluble fertilizer may value the specified blend and included scoop. It also lists other flowering ornamentals, but the supplied directions lack a complete mixing rate, a relevant limit for planning applications.

Listed on Amazon as: Natures Wisdom Crepe Myrtle Tree 8-55-7 Water Soluble Fertilizer Plant Food, Balanced Nutrient Blend for Flowering Trees, Shrubs and Vines | 1.5 Lb

#9

9. Down To Earth Organic Acid Mix

• Form: Granules
• Weight: 40 lb

Best for: Slow-release feed for acid-loving plants.

Why it ranks #9: The organic slow-release 4-3-6 formula is not identified for crape myrtles, and its instructions say not to apply it where food crops will be grown.

A slow-release 4-3-6 organic acid mix offers a steady nutrient supply for gardeners seeking less frequent applications. The granules can be applied to the soil surface or mixed into soil during planting, giving crape-myrtle growers two listed ways to incorporate this broad organic fertilizer.

The slow-release formulation is described as providing a steady supply of nutrients and reducing the need for frequent applications, which can simplify upkeep. Surface application or mixing into soil during planting supports both established beds and new plantings; the directions say to water it in well either way. Despite the acid-mix name, the product facts explicitly say it does not adjust soil pH. Its 40-pound package is a substantial quantity to handle and store.

Skip it if you need to change soil pH as well as feed plants; this fertilizer does not adjust pH, so select a separate soil amendment.

Choose this for a large planting area where slow-release granules and flexible soil application suit your routine. It can feed crape myrtles, but it will not alter soil pH, and its 40-pound package calls for suitable handling and storage.

Listed on Amazon as: Down To Earth All Natural Fertilizers Organic Acid Mix – 4-3-6, 40 lb