Organic Seed Starter Fertilizer 4-6-4

Yes. Suståne 4-6-4 is derived entirely from organic ingredients and is allowed for use in the production of certified organic crops. It is an excellent choice for vegetable gardens, herb beds, fruit trees, and flower gardens. For new garden beds, apply 3 lbs per 100 sq ft (about 1 cup per 10 sq ft) and work into the top 4 inches of soil before planting. For transplants, place 1/4 cup in the planting hole before setting the plant. Reapply as a topdress in spring and fall to maintain fertility.

No. Suståne 4-6-4 is specifically designed for use with new seedlings and transplants. It has a near-neutral pH, low salt index, and only 0.4% ammoniacal nitrogen—the form most likely to cause burn. The remaining 3.2% of nitrogen is water-insoluble (slow-release), meaning it feeds gradually as soil microbes break it down. This gentle release pattern matches the pace of seedling growth. You can apply at the full recommended rate (25 lbs per 1,000 sq ft for new lawns) without risk to young turf.

The two products serve different stages of plant growth. The 4-6-4 Starter is phosphorus-forward (the 6 in the middle) to drive root development during establishment. The 18-1-8 Maintenance is nitrogen-forward (the 18) to feed leaf growth and color in established turf. Use 4-6-4 when planting new seed, laying sod, or transplanting. Once your grass is established and has been mowed 2–3 times (about 6–8 weeks), switch to 18-1-8+Fe for ongoing maintenance. The 4-6-4 is also fully organic, while the 18-1-8 is organic-based (combining organic compost with synthetic controlled-release nitrogen).

No. Unlike raw animal byproducts, the ingredients in Suståne 4-6-4 are aerobically composted at high temperatures before processing into granules. This composting process eliminates the odors that attract wildlife. The finished product has an earthy, soil-like smell—not a meat or manure smell. That said, dogs are sometimes attracted to organic fertilizers and may try to eat granules. We recommend keeping pets off treated areas until the product is watered in and the lawn has dried.

Coverage depends on your application type. At the full new-lawn establishment rate (25 lbs per 1,000 sq ft), one 50 lb bag covers approximately 2,000 sq ft. At the overseeding rate (6 lbs per 1,000 sq ft), one bag covers about 8,300 sq ft. For garden bed prep at 3 lbs per 100 sq ft, one bag covers roughly 1,667 sq ft. Most homeowners seeding a typical 3,000–5,000 sq ft lawn will need 2–3 bags at the new establishment rate.

Yes—in fact, mixing with seed is one of the best application methods for overseeding. Combine 6 lbs of fertilizer with enough seed for 1,000 sq ft in a bucket and mix thoroughly. Then spread the blend with a broadcast or shoulder-bag spreader. The granules are similar in size to grass seed (200 SGN, 1.4–2.8 mm), so they distribute evenly together. This method ensures every seed lands near a nutrient source, giving it the best possible start. For new lawn establishment at heavier rates, broadcast the fertilizer separately and incorporate into the soil before seeding.