Grass Seed

How to Store Leftover Grass Seed

Leftover grass seed

I’ll never forget the years I spent working as a property manager for a client with a seven acre estate. This client was what you’d call “well off”, and had several large sheds and garages scattered throughout his property. While most folks have junk drawers in their home, this client had junk sheds. One spring day while doing some organizing and cleanup in one of the garages I found a bag containing a few pounds of grass seed. The seed was almost 5 years old! My first thought was to throw it away, but just for fun I scattered the seed in a thin area of the lawn and raked it in. To my surprise, some of the seed actually germinated. Not much, but some. Had the seed been stored under proper conditions I’m sure the germination rate could have been much higher. 

Save Leftover Seed For Future Planting

I share this story because one of the most commonly asked questions here at Nature’s Finest Seed has to do with grass seed storage. Sometimes after planting a new lawn or overseeding an existing lawn it’s normal to have some leftover seed. Instead of throwing it away or scattering it over your lawn, keep it for later use. Leftover seed can come in handy for filling in bare or thin spots in the future. It’s also great for quick repairs after sprinkler work or lawn damage. 

How to Store Grass Seed

To properly store grass seed, first make sure it’s placed in the right kind of packaging. Breathable packaging is best, such as a cloth sack or burlap bag. Breathable materials will allow good air flow and reduce the risk of molding. However, if you have a full unopened bag of grass seed it’s best to leave it unopened in the original packaging.

Where to Store Grass Seed

Next, place the seed in a cool dry area that has some air circulation. Avoid areas that will freeze. This includes sheds and unheated garages. Basements and cellars are usually a good choice as long as they’re dry. If moisture is a problem, place an open box of baking soda or some other type of desiccant in the seed bag. For those of us without basements, closets work well too. Refrigerators can also be used if available. Set the temperature between 40 and 50 degrees Fahrenheit and use a desiccant to remove excess moisture. Wherever the area, be sure to keep the bags off the floor and in a place where mice and other rodents can’t get to them. Nothing will destroy a bag of grass seed faster than a few hungry mice during the winter. 

How Long Will it Last?

When stored under these ideal conditions, grass seed should last between 10-18 months from the testing date without a significant decrease in the germination rate. After this time the seed can still be used, but each year after that will see the germination rate drop. Most sources report a 10-20% decrease for every year grass seed is stored.