Q: We built a house last summer and finally moved in last November. We were told we needed to plant winter ryegrass as it was the only thing that would grow enough to prevent erosion on our new soil. Well, it is just about time for it to start dying off and we need to plant some new grass to replace it. We have decided to go with centipede grass. Do we need to go through the headache of tilling up all of the soil again, or can we just aerate the area really good and sow the centipede seed?
A: If you think you’ll have headaches tilling the soil, wait until you have to pull weeds by hand for two weeks while waiting for your centipede seed to sprout! Planting centipede seed seems like a good idea but it is not nearly as easy as planting fescue or ryegrass seed. Whereas the cool season grasses germinate in just a week, centipede takes two or three weeks to show much greenery. If you simply aerate the soil and scatter centipede seed, the existing grass shades the seedlings and slows their development. If you till the plot and plant centipede seed on fresh soil, weeds begin sprouting within days and must be removed quickly before they compete with the new grass. Add to this the necessity of watering lightly twice a day for two weeks to keep the centipede seed moist at all times!
Centipede sod is a great option but if you just moved into your house you probably don’t have much money left for sod. If your site is sunny, I’d aerate like crazy and sow the centipede seed in mid-May, then fight the weeds as best I could for the summer. Next year you can use selective herbicides to battle the weeds but not while the centipede is establishing itself.