How do I encourage lawn seeds to germinate successfully?

Question

I'm trying to repair some patches in my lawn with grass seeds, but I can't seem to get the seeds to germinate. Is there anything that can be done to encourage germination?

In addition, the weather has been really changeable of late, so it's wet and cold for a few days and then hot and dry for others. Is there anything I can do to give the grass some consistent warmth and moisture?

Answer 1

Some tips that have worked for me:

• Loosen up the soil before scattering the seeds so that the seeds aren't trying to penetrate firm soil.
• Mix the seeds with some compost or sand so that they're not all lying exposed on top of the soil.
• Press the compost/seed mixture lightly into the existing soil.
• Water twice a day until the new grass is established.

As for maintaining consistent moisture, you can reduce or eliminate the water on wet days and water it only on the dry ones. I wouldn't worry too much about the temperature variation as long as you're keeping the soil moist.

Answer 2

Is your lawn a warm season lawn or a cool season lawn?

If it's a warm season lawn, I believe the best time of year to establish (or repair) is mid spring to very early summer. For a cool season lawn, the best time of year to establish (or repair) is from August 15th to September 15th (exact date will vary slightly depending on the growing zone you're in).

Niall C.'s answer is a good one, but if you require more detailed information regarding the establishment of a cool season lawn, you may wish to take a look at the following University of Missouri Extension document - Cool-Season Grasses: Lawn Establishment and Renovation.

Some info that is relevant to your question:

Watering

Newly seeded or sodded lawns require special irrigation. A newly seeded lawn requires daily watering and may need as many as four light waterings in a single day if conditions are dry and windy. Keep the seedbed moist, but not saturated, to a depth of 1 to 2 inches until germination occurs (green cast to lawn and seedlings 1/4 to 1/2 inch tall). At this stage, it is crucial that seedlings not be stressed to the point of wilt.

Also since you're repairing your lawn, this part might be relevant to you:

Renovating tips

Prepare surface for seeding

One of the most important steps in renovation is placing the seed in contact with soil. This sounds simple, but most lawns have thatch - an intermingled layer of both dead and living plants - over the soil surface. This brown, decomposing layer may be up to 1 1/2 inches thick. Lawns with more than 1/2 inch of thatch should be dethatched.

Seed placed on or in the thatch layer may germinate, but the eventual stand of grass that develops will be poor. To ensure good seed-to-soil contact, use power equipment to prepare the surface for seeding. Power rakes, verticutters, slit seeders and core aerators are effective machines for properly preparing the surface for seeding.

Answer 3

In the UK:

• Ground temperature must be over about 8C
• Seeds must be kept damp (but not washed away)
• Seed must not be eaten by birds
• Seed must be able to get its roots into the ground

So

• Don’t try in winter
• If you are not going to water, then avoid the summer.
• Cover the seeds with a fine layer of compost/sand/soil
• Loosen up the soil and remove any dead grass.

(I know that some parts of the US have a different type of grass.)

Answer 4

Covering seeds with a thin layer of compost or peat moss helps create a moist layer to prevent the seeds from drying out. Also will hopefully keep birds from eating the seeds. And of course, you must keep it damp (water twice a day during warm weather) for proper germination.

Answer 5

Good answers already here but I will put in my two cents:

Here in Ohio with a freeze/thaw cycle, the soil heaves up and down and creates all sorts of nooks and crannies. I overseed in early winter and this heaving crates great soil to seed contact, then when spring comes I have great results. You just can't use weed preventer with dormant overseeding.

For patching, I learned this from a forum post. The poster had a grandfather that worked as a landscaper at a cemetery. I use a 5-gallon bucket or a wheelbarrow for larger patches and pre-mix the seed and soil together slightly damp. I keep it in the garage at a higher temperature until the seeds start to germinate, THEN lay it down and water it. This method raises germination rates and cuts the germination time to like 25%.