Fall is an ideal time to work on your lawn.
The desirable grass plants can still thrive, while the undesirable weeds and crabgrass have already called it a season. If you look at your lawn and see brown patches along pavement, on hillsides or, worse yet, throughout the main lawn areas, there is a good chance you have crabgrass.
The second half of this past summer was ideal for crabgrass, since the hot and dry weather reduced the competition from the “good” grass just as the crabgrass was setting its seed. So if nothing is done, next year should be a banner year for crabgrass.
Now crabgrass is a grass, so the same chemicals that kill it kill your lawn. So the best way to fight this fire is with that fire: coddle the grass you want so that there is less room for the grass you don’t want. And fall is a great time to amp up the coddling so next year you will have a thicker turf.
With thicker turf in mind, I recommended to a do-it-yourself friend that she apply a heavy dose of organic fertilizer this fall. She went shopping and found herself considering peat moss as a soil amendment. Should she buy it?
To me, there are two important uses for peat moss and lawns. First, if you are overseeding a thin or bare spot, when you water, peat moss will hold the moisture close to the seed so that it will germinate, and peat moss will provide a soft medium in which the seed may sprout roots. Second, if you are trying to improve your soil composition near the surface of your lawn, you may apply peat moss to fill the holes after aerating.
But there are liabilities in both cases.
In the first case, the peat moss can easily wash away in a hard rain. In the second case, the aeration depth is so shallow that you are not improving the soil throughout the entire root zone. Furthermore, peat moss adds almost no nutrients, so you will need to fertilize anyway.
So let’s think about adding nutrients and boosting your turf. Some chemists argue that regardless of the source – organic or synthetic – the actual nutrients the plant uses are chemically identical. While this may be the case, synthetic fertilizers deliver the nutrients in a salty “package” that can be harmful to plants and other life forms in the soil. (Think fertilizer burn.) But the “packaging” for organic fertilizers actually improves the soil and attracts tilling creatures like earthworms.
In every season’s use of a commercial organic fertilizer, on a half-acre lawn you will add a quarter of a ton of organic matter. And if you remove the clippings, you have to add 250 pounds more. Instead of peat, for best results, fertilize more.
Joshua Arp is an ISA-certified municipal specialist, Clarks Summit’s municipal arborist and an operator of an organic lawn and landscape maintenance business. Reach him at firstname.lastname@example.org.