Does grass seed go bad? Yes. You can tell if your grass seed is still good by inspecting four basic things: sight, smell, feel, and weight. For example, your seeds might have splotchy colors or feel brittle if they’ve gone bad.
After taking your grass seed out of storage, a thorough inspection should easily reveal whether the seed is still good or if you need a new bag. If your grass seeds show no signs of going bad, there are some simple tests you can perform to check their viability.
4 Signs Your Grass Seed Has Gone Bad
If stored incorrectly or left for too long, grass seed can expire and lose its viability. If you try to plant expired grass seed, you’ll only wind up wasting time, energy, and resources on a lawn that won’t grow.
When you’re about to plant your new lawn, stop and take a moment to inspect your seeds. Pay close attention to their color, smell, feel, and weight. Here’s what you should be looking out for:
1. Seeds Are Discolored
The first way you can tell if grass seeds are still good or not is with a visual inspection. Take a handful of grass seed and go over it with a close eye. See if there are any changes in its physical appearance.
Grass seed that’s gone bad looks discolored. Look for any seeds that are splotchy, faded, or dull. Some grass seeds become darker in color if they’ve expired. You may even be able to see visible mold or fungus, which is a sure sign that the seed is no longer viable.
Conversely, grass seeds that are still good to plant will look vibrant. They should be uniform in color across the bag with no signs of mold or fungus.
2. Seeds Smell Musty
The next step in inspecting your grass seeds is a smell test. Take a big whiff of your seeds. If grass seeds have gone bad, they typically smell musty, or even rotten. Sometimes, you’ll notice a smell like something has started to ferment. If the seeds smell at all off, they’re likely no good.
In comparison, grass seed that’s still good will smell fresh. If you already used some of them previously, try and remember what the seeds smelled like when you first bought the bag.
3. Seeds Feel Brittle (or Mushy)
Another way to tell if your grass seed has started to bad is to feel it. Take some seeds and feel them carefully. Expired grass seed feels very different from seeds that are still viable. Nonviable seeds may feel mushy or brittle. If you try to squeeze some, you might find that they break easily. If so, the seed has expired.
Good grass seeds are firm and strong. If you press them between your fingers, they should feel hard and not break.
4. Seeds Feel Lightweight
The last thing you should check for when inspecting your grass seed is its weight. This is a bit more difficult to measure since it’s not a sense like sight or smell, but it’s a valuable indicator nonetheless. Take a handful of seeds and try to gauge their weight. Ask yourself if the grass seeds feel at all light. If so, they might be expired.
Grass seed that’s still viable is heavier than expired seed. Look for other indicators and judge whether or not you feel the seed is still viable.
How to Test If Your Grass Seed Is Still Good
Of course, it’s possible for grass seed to have lost its viability and show no outward signs. If you’re still unsure after carefully inspecting your grass seeds, you can test them. There are two ways to definitively test whether grass seed is still viable: the float test and germination test.
Once you know your grass seed is still good, you’ll find this guide helpful for planting it: How to Plant and Grow Grass Seed in 9 Steps
Float Test
The first method is the float test. Take some seeds and put them in a bowl of water. To make counting them easier after the test, use a multiple of 10; for example, 20 or 30 seeds. If 80 percent or more of the seeds float after 15 minutes, then the bag is still good and you’re good for planting.
If 50 percent or less float, you either need a new bag or need to double the amount of seeds you plant.
Germination Test
The second test is the germination test. This test is more time-consuming than the float test, but also more accurate. Take some seeds and try to germinate them. Just like the float test, use multiples of 10.
Place your seeds on a wet paper towel, seal it in a plastic bag, and put the bag somewhere warm. Wait one week and see if the seeds start to grow. After a week, if 80 percent or more sprout, you’re good!
If 50 percent or less sprout, buy a new bag or plant extra grass seed.
FAQ About Grass Seed
Is grass seed viable if water has gotten to it?
Likely not. If only the packaging got wet, you can dry it off and store the bag correctly. If the seeds themselves got wet and then dried out, they’re probably either already expired or will expire soon.
Can you revive expired grass seed?
No. Once grass seed has spoiled, you can’t bring back its viability.
What’s the best time of year to plant new grass seed?
It depends on the grass type. If you’re planting warm-season grass, like Bermudagrass or St. Augustine, the best time of year to plant is late spring or early summer.
On the other hand, if you’re planting cool-season grass, like fescue or ryegrass, plant in early spring or early fall.
For more information, read our article on When is the Best Time to Plant Grass Seed?
Find a Lawn Care Expert
You should always inspect your grass seed carefully before trying to plant it. If you accidentally use bad seeds, you can expect a patchy, unhealthy lawn.
If you need help with your grass, contact lawn care professionals near you. They can mow and maintain your lawn for you so that you have more time to yourself.
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