How long do lawn seeds keep? Gardeners ask this question again and again. We reveal how to properly store seed for the lawn and how long lawn seeds can be kept and germinated.
When calculating the right amount of lawn seed, it's easy to make a mistake - and now what? Leftover seeds are a valuable commodity, especially if you have opted for high-quality seed mixtures such as our Plantura lawn seed mixtures. So throwing it away is out of the question. The seeds can be used to quickly repair imperfections, or perhaps the lawn area should simply be expanded in two years. We explain how lawn seeds remain germinable for a long time and which seeds have a particularly high germination capacity.
Storage of lawn seeds: How to do it right
Lawn seeds last the longest in cold, dry and dark conditions. While higher temperatures don't necessarily promote shelf life, they're not the biggest problem. Extreme heat and temperature fluctuations should be avoided at all costs. Incidentally, storing lawn seeds in frost is also completely unproblematic. Humidity is a factor that is often underestimated. Humid air can drastically reduce the germination capacity of lawn seed in the long term. A relative humidity of 30% is therefore optimal. It is often cool and dry in modern basement rooms or well-insulated and solidly built garden sheds. In addition, lawn seeds are best stored in the dark so that germination-promoting processes in the seed are not stimulated.
Tip: Moisture can also be a problem when storing grass seed in a thin plastic sack. If the temperature fluctuates, condensation quickly forms there, which causes the seeds to germinate unintentionally or leads to mold. To avoid such a storage breakdown, the seed can be transferred to paper or fabric bags.
Summary: How To Store Lawn Seed Properly
- Storage cool and dry, temperature fluctuations should be avoided
- Frost is not a problem, but heat is
- Storage in dark containerswhere no water condenses (e.g. slightly open containers, paper bags or cloth bags)
How long do lawn seeds keep?
Unfortunately, this is not stated on the packaging: So how long does grass seed keep? If stored correctly, high-quality grass seeds will remain sufficiently germinable for three years. The germination capacity then drops by around 10% per year. You can easily compensate for this poorer germination rate with a higher application rate, but you should definitely create optimal germination conditions for these slightly older seeds. We will show you how and when to sow the lawn ideally.
Even a perfect supply of nutrients promotes the emergence of slightly older lawn seed: A primarily organic lawn fertilizer such as our Plantura organic lawn fertilizer can be distributed directly before sowing.
In particular, lawn seed mixes containing different genera of grasses, should not be used after the fifth year, even if they have been well stored. Not all of the different grasses can be stored equally well, so that only part of the mixture may germinate when sowing. The result is an incomplete lawn that is missing, for example, the undergrowth or the important stoloniferous grasses.
Tip: If you still want to use a lawn reseed like our Plantura Premium reseed after it has been stored for a long time, you can simply carry out a germination test. Even if the seed only partially germinates, it can be used - no matter how old it is. Reseeding usually only contains one type of grass, so that later sowing does not lead to the problems mentioned with a changed composition. For a germination test, simply sow a few seeds in a flower pot on normal potting soil, press down and keep moist at a minimum of 8°C for 10 to 14 days. If only a portion of the seeds germinate, simply sow the seeds a little more liberally when reseeding.
How do you recognize overlapping lawn seeds?
If lawn seeds have been stored incorrectly or for too long, they become soft, start to germinate or mold grows. In addition, they no longer smell dry and spicy, but musty and unpleasant. If you're not sure, pick up a seed. If it is dry, firm and sharp, it can still be used. You can then test the germination capacity with a germination test in potting soil.
Which lawn seeds have a long shelf life?
High-quality, carefully produced lawn seeds have a high germination rate. All seeds that are placed on the market in Germany must meet a minimum quality standard. The quality of seeds is checked and all seeds must - at the time of purchase - meet a certain variety-dependent germination rate.
Certified seed from standard seed mixtures, i.e. RSM-certified seed, achieves particularly high germination rates. This is evaluated according to criteria that are even stricter than those prescribed by law, and therefore germinates at higher percentages and even after longer storage. RSM-certified seeds such as our Plantura Premium seed mixtures have a particularly long shelf life and are capable of germination.
You have just seeded your new lawn and maybe the first seedlings are already appearing? In our special article on sowing a lawn, you will also learn what the very first care of a young lawn should be.