Fall (September, October, November)
- If you fertilize only once a year, a single application early September is the best time. Most home lawns with modest expectations do just fine with a single fall fertilization.
- Control broadleaf weeds in fall. Controlling broadleaf weeds like dandelion, clover, plantain is best done in the fall. If hand pulling or digging is not practical for your lawn and large areas are infested with a wide variety of broadleaf weeds, an herbicide treatment may be necessary.
- Do not fertilize during “Indian summer” – a warm period following hard frost. This may cause excessive top growth, reduce root storage and increase the likelihood of winterkill.
- Keep up the regular frequency of mowing and be sure to keep lawn clippings and tree leaves out of roadways or drains. Leaves can blow or wash away and pollute waterways with phosphorus. Shred fallen leaves with a mulching mower or collect leaves and compost them before snowfall mats down the lawn, which can kill turf.
- Avoid walking on grass until frost burns off. Foot traffic can easily injure or kill frosted plants.
- Do not fertilize after November 1.
Above information obtained by the Suffolk County Department of Economic Development and Planning https://healthylawns.suffolkcountyny.gov/lawn/tips.htm