About Us

The Story of Nutri-Pak®

Kirkwood Industries, Inc. is the manufacturer of the Nutri-Pak® Controlled Release Fertilizer Packet System, an innovative fertilizer solution that was originally developed in conjunction with leading experts in plant nutrition to specifically address the nutritional requirements of all types of plants in a way that is safe for people to handle, and that will not harm the environment. As a trusted fertilizer supplier, Kirkwood Industries continues to focus on sustainable and responsible plant nutrition solutions.

At Kirkwood Industries, we are not only committed to supplying the world with environmentally safe fertilizer products from Fond du Lac, WI, but we are also dedicated to educating the world about the dangers of groundwater contamination and the potential loss of our natural resources due to the extreme overuse of chemical fertilizers. As an environmentally responsible fertilizer supplier, we recognize that everyone—from homeowners to large commercial growers, nurseries, landscapers, and municipalities—contributes to these problems when using current fertilizer methods. With proper education and the Nutri-Pak® technology, we can change the way the world fertilizes, and thereby change the direction the world is currently headed.

The American Forestry Association, in Washington, D.C., invited Kirkwood Industries, Inc. to be one of their national corporate partners with the American Forests Global ReLeaf® campaign. It was an honor to be chosen in the campaign’s first year in 1989 because of the environmental impact of our fertilizer products and our role as a responsible fertilizer supplier.

About Nutri-Pak® Products

Nutri-Pak® fertilizer packets have a revolutionary method of delivering nutrients to a plant’s root zone. This method guarantees that nutrient loss due to leaching or runoff is averted; the cost of labor and supplies is reduced, and the damage to the plant from too much fertilizer is eliminated. Nutri-Pak® is ideal not only as a tree fertilizer but also as a reliable fertilizer for flowers, supporting healthy growth across a wide range of plant types. Nutri-Pak® is also safer for you and the environment because the packets are installed unopened, so you never come into contact with the fertilizer itself. Also, there will be no surface or groundwater contamination because of its very controlled release.

How They Work

Each fertilizer packet contains a pre-measured amount of precisely formulated nutrients for proper feeding. Simply bury the required amount of packets 6 to 8 inches deep into the soil, evenly spaced around the root system of a plant. Microscopic pores allow water vapor to enter the packet, dissolve the nutrients, and then release the fertilizer to the feeder roots gradually and consistently. Nothing could be easier— no mixing, no measuring, and no mess. Also, Nutri-Pak® lasts for either one or three years (in year-round growing conditions), depending on the packet size selected.

Benefits of Our Fertilizer Products

The packet method significantly improves the plant’s use of fertilizer, making it possible for only a few ounces of fertilizer to last up to three years, even in tropical zones. This efficient use of nitrogen greatly reduces the potential for excess nitrates to enter our water supplies.

All plant species show improvement when nutrients are made available to them slowly and consistently, which is the inherent characteristic of Nutri-Pak® fertilizer packets. Consider using Nutri-Pak® for your current or next planting job, and judge for yourself if you find Nutri-Pak® to be a beneficial addition to your growing program:

Dramatically increases growth rates
Provides nutrients up to three years* with just one application
Helps municipalities protect landscaping investments without worry
Reduces over- or under-feeding and improper placement of fertilizers
Makes it easier for nurseries to grow healthier plants with less fuss and less manpower
Safer for the environment, helps eliminate harmful groundwater pollution
Supplies nutrients only during the growing season
No mixing, no measuring, and no mess
Assists growers and landscapers by promoting faster growth to maturity
Eliminates the danger of shocking or burning young root systems
Foolproof installation for homeowners and landscaping crews because it takes the guesswork out of fertilizing
Earns profits for lawn and garden centers because it saves time and money for customers
Safer for you because the packets are buried unopened so you never come in contact with the fertilizer itself

*Length of feeding period normally lasts three years; may last up to five years in northern zones.

Why Nutri-Pak® Is Different

Traditional fertilizer is typically spread across the soil surface. After rain or irrigation, some of those nutrients may move away from the plant through runoff, leaching below the root zone, or losses to the atmosphere.

Nutri-Pak® takes a different approach.

Instead of leaving fertilizer on top of the soil, Nutri-Pak is placed underground beside the plant’s roots. Nutrients are released gradually in the root zone, where the plant can access them over time.

The result is controlled feeding for 1–3 years, right where the plant needs it.

More Than Just Slow-Release Fertilizer

There are many slow-release fertilizers available, but Nutri-Pak® combines several advantages in one system:

Controlled nutrient release

A contained fertilizer packet

Placement directly in the root zone

Multi-year feeding

This combination helps keep nutrients close to the roots instead of spreading fertilizer across the soil surface.

What Happens to Traditional Fertilizer?

Plants do not always use all of the nitrogen that is applied to the soil.

Depending on the fertilizer, soil conditions, weather, irrigation, and application method, research has shown that a significant portion of applied nitrogen can be lost before plants are able to use it.

Nutrients may be lost through:

Surface runoff

Leaching below the root zone

Losses to the atmosphere

Other natural soil processes

In some conditions, 50–70% of applied nitrogen may be lost before plants use it.

That is why Nutri-Pak® focuses on both controlled release and placement.

Traditional Fertilizer vs. Nutri-Pak®

Traditional Fertilizer

Fertilizer is spread on the soil surface.

Rain and irrigation can move nutrients away from the application area.

Some nutrients may run off, move below the roots, or be lost to the atmosphere.

Less fertilizer may remain available to the plant.

Nutri-Pak®

Nutri-Pak® is placed beside the roots.

Nutrients are released gradually over time.

The roots receive nutrients directly in the root zone.
Controlled feeding continues for 1–3 years.

A Smarter Way to Feed Plants

Nutri-Pak® is more than a slow-release fertilizer. It combines controlled nutrient release, a contained fertilizer packet, direct root-zone placement, and multi-year feeding to create a more targeted way to nourish plants. Instead of spreading fertilizer across the soil surface, Nutri-Pak® places nutrients where the roots can access them and releases those nutrients gradually over time. By putting nutrients where the roots are, Nutri-Pak® helps feed the plant consistently while reducing unnecessary nutrient loss.