In the previous turf practices installments, we discussed core aeration and spreading compost on your lawn. The next step we take here is to sow grass seed in places wearing thin due to shading or a season of public use. The general rule in this part of the country is to sow your cool season grass seed (i.e. Kentucky Bluegrass) in spring or fall. There is a suggested “best time to plant” window from August 15 to September 15 where soil conditions are warm enough, the days warm, but not too warm, and adequate moisture to germinate seed plus growing time to put down roots before winter arrives. Though that “ideal” time has past, it is not too late. If we get an Indian summer like we are now experiencing, seed will still take off.
There are several steps and possible methods. One can rent a “slit seeder” which plants the seed directly into the soil. This is perhaps the best method for large areas. Placing the seed directly in the ground provides the best chance for germination. For fixing patches at Wellfield, we use a simpler, cheaper approach.
1. Prepare the ground
The soil should be free of weeds, thatch, and roughed up a little. There is no need for tilling the ground in most cases, as grass roots do not go that deep. Raking the ground with a stiff tined rake is sufficient. We utilize the loose layer of freshly spread compost, as detailed in Part 2 of 5: Compost Topdressing, in our case.
2. Sow seed
Next, spread the seed on the soil surface either by hand or some type of spreader. Bags of seed will tell you how thick to spread it. This is good information for estimating how much you need. I simply spread it so there is perhaps five to six individual seeds in a space the size of a quarter.
If you are following along, you will notice I did not say to bury the seed, just sprinkle it upon the soil surface. Grass seed is fairly thin and small letting the sower know it does not need to be planted deeply. Rake the area with the backside of a leaf rake. This is all the cover grass needs.
4. Firm the ground
After raking the seed into the soil, firm the soil with a roller, mower turf tires or your feet. You are not hurting the seed at all. This is an important step. There needs to be good seed to soil contact in order for grass seed to take up soil moisture to germinate.
Next, apply a layer of mulch to retain soil moisture. Weed free straw is an excellent cheap option. We prefer to use news paper pellets sold often as turf seed starter. Pellets are more expensive, but do a better job of both covering and retaining moisture than straw.
Lastly, keep the seed evenly moist for best results. Supplement rainfall with a short, frequent burst of moisture as needed. It does not take much, especially with a mulch layer, but it is critical seed not dry out.
Follow these simple steps and you will have beautiful grass growing in no time. Next week: feed that new (and old) turf stand with an organic granular fertilizer.
Note: If you missed Part One: Core Aeration, or Part Two: Compost Topdressing, follow these links to catch up!