Label Spec Sheet MSDS
Slow Release Fertilizer a in Biodegradable Filter Pack
180 - 250 Day Nutrient Release at 70º F


16 4 8 Root Zone Feeder Pak box bag


Suståne 16-4-8

Root Zone Feeder Paks provide single-dose applications of Suståne organic and controlled release fertilizers designed to provide long-lasting plant nutrition in a completely biodegradable paper filter pack. This product is designed to provide a continuous release of nutrients for up to 8 months at 70º F (23º C) soil temperature.


Recommended Use:

Suståne 16-4-8 Root Zone Feeder Pack is designed for use in all flowers, trees, shrubs, and perennial plantings including landscape areas, potted plants, and hanging baskets.

Features of Suståne 16-4-8 Root Zone Feeder Packs:

  • Assures controlled dose applications
  • Suståne Organic+CRF produces predictable results, dependable performance, and high-quality plants.
  • 50% Suståne All Natural Compost Based Fertilizer
  • 50% coated 6-month Controlled Release Fertilizer
  • One application per plant per growing season.
  • Low burn potential, nutrients release gradually over time.
  • In permeable biodegradable paper filter packets.
  • No measuring, no special equipment, no waste.

Benefits of Suståne 16-4-8 Root Zone Feeder Packs

  • Rich in humic acids
  • Increases the nutrient and water holding capacity of the soil
  • Strengthens plants tolerance against hot dry conditions
  • Promotes greater root development
  • Improves buffering against changes in soil pH
  • Increases the soil’s ability to suppress plant pathogens
  • Increases soil porosity and stability for greater root development and water holding capacity

Always Safe for Plants, People, and the Environment

  • Manufactured by Suståne in the USA at an EPA permitted facility.
  • Pathogen and weed-free, no blood or bone products. Allowed for export to over 60 countries worldwide.
  • Aerobic composting eliminates animal and rodent attraction to the application site.
  • Contains naturally occurring beneficial bacteria and fungi that are necessary to begin the nutrient life cycle in poor soil.
  • Suståne is fully composted eliminating the need for sterilization, permitting a healthy environment for beneficial microbial populations.

Suståne® Enhanced with Sumicoat™ Controlled Release Fertilizer

Sumicoat™ Controlled Release Fertilizers are polymer-coated controlled-release fertilizers initially tested and developed for the rice production markets in several different climates in Japan. Sumicoat products have been used for years to release precisely the right amount of fertilizer to optimize plant growth. For the past several years Suståne has been evaluating different Sumicoat release products blended with Suståne organics to create the optimal nursery and greenhouse fertilizer combinations. Suståne and Sumicoat have been proven through years of research to provide the winning combination that will not under or over release.

See how Suståne 16-4-8 Root Zone Feeder Packs worked in the field for a Christmas Tree Grower: Download or view the PDF.

Guaranteed Analysis

Total Nitrogen (N) 16%
0.2% Ammoniacal Nitrogen
1.8% Water Soluble Organic Nitrogen
2.6% Water Insoluble Organic Nitrogen*
11.0% Urea Nitrogen*
0.4% Other Water Soluble Nitrogen
Available Phosphate (P2O5) 4%
Soluble Potash (K2O) 8%
Calcium (Ca) 2.75%
Magnesium 0.75%
Sulfur 1.00%

Total Plant Nutrition

Iron 0.25%
Manganese 0.05%
Zinc 0.05%
Humic Acid 5%
Organic Matter 45%
pH 6.8
Carbon: Nitrogen (C:N) 2:1
Bulk Density lb./cu. ft 42
% of Total N as Slow Release 90%

Derived from aerobically composted turkey litter, polymer-coated urea, polymer coated potassium nitrate, polymer coated monoammonium phosphate, ureaform, feather meal, and sulfate of potash.
*12.7% controlled release nitrogen derived from polymer-coated urea, polymer coated potassium nitrate and polymer coated monoammonium phosphate.
**2.6% slow-release nitrogen derived from aerobically composted turkey litter, ureaform, and feather meal.

Directions for Use: Simply insert Feeder Pak(s) into the root zone of potted or bed grown plants at planting or re-potting time or during routine fertilization maintenance after plant establishment.

Potted Plants and Hanging Baskets: Install one Suståne Feeder Pak per 1-gallon pot inside root zone; two paks per 2-gallon pot; three per 3-gallon pot.

Flower beds and Perennials: Install one Feeder Pak 2-4 in. below soil surface within 6-inch radius of plant stem or midway between stem and drip line of plant canopy.

Shrubs and Young Trees: Install one Feeder Pak per every 12 in. height of plant (2 for 24 in. ht., etc.) 4 - 6 in. below soil surface midway between stem and drip line.

Compost Tea: Place 1 - 3 tea bags into a 1-gallon watering can, let steep for 12 to 24 hours, apply topically to leaves and soil. Use or discard within 36 hours. Reapply fresh tea weekly.