Should You Seed or Fertilize Grass First?

Preparing for Seeding

• Check the thatch layer before reseeding the lawn in the spring. Remove thatch before fertilizing, because fertilizer will not penetrate a thick thatch layer. Removing some of the thatch and dead grass opens up bare spots. Cut a 2-inch wedge of turf out of the lawn. If the thatch layer is more than 1/2 inch, dethatch your lawn with a power dethatcher.

Seeding

• Tilling the lawn's bare areas breaks up the soil for reseeding. Smooth these areas with the back of a rake. Broadcast grass seed over the bare areas. Cover the seeds with 1/8 inch of compost and water. Keep the seeds moist while they germinate by watering the lawn several times a day. If the grass seeds dry out, they will not germinate. Mow you new seedlings when they reach 3 inches in height.

Preparing for Fertilizing

• Getting a soil test from you local cooperative extension office saves time and money. Choosing a fertilizer without knowing what the yard needs may cause a build up of phosphorous, which leads to weed problems, according to the University of Illinois. Dig 10 6-inch holes in the yard. Collect half of a cup of fertilizer from each hole and mix them in a bucket. Send a half cup of soil to your local cooperative extension. The office sends back results telling your soil's pH range, fertilizer recommendations and soil amendment suggestions.

Fertilizing

• Fertilizer your lawn as recommended by your local cooperative office. If you opted out of getting a soil test, use a balanced fertilizer with a NPK amount of 10-10-10, as recommended by the University of Illinois. Regardless of the fertilizer you use, avoid applying more than 1 lb. of nitrogen. Water the fertilizer into the lawn and apply a fertilizer again in the fall.