Spring Seeding Cool-Season Lawns

A picture of a lawn

March and early April are prime times to seed your cool season lawns. Especially, if you have any shade. After May 1, your success rate really drops off.

By Glennon Kraemer

First published in The Gateway Gardener March 2014

March and early April are prime times to seed your cool season lawns. Especially, if you have any shade. After May 1, your success rate really drops off.

Here are my Step-By-Step instructions for spring seeding jobs:

  1. Wait until you can rake or blow winter leaves and have mowed at 2” to remove any unwanted materials in the lawn.
  2. You probably won’t have your irrigation running yet, so be careful when you aerate or power rake the thin areas. You don’t want to damage the irrigation system!
  3. Spread your seed (usually 5-10 lbs./1000 ft. sq.) and some “starter” fertilizer like 10-20-10. Don’t worry about crabgrass control (shade areas won’t grow crabgrass anyway) for now.
  4. Rake back and forth to ensure good seed to soil contact. Seeds need water and soil temperature to germinate, not sunlight. The best seed job is one that you can’t see the seed when you are through.
  5. Top dress areas with more topsoil (1/2”), compost or PennMulch ®. This will help maintain moisture and prevent erosion.
  6. Water lightly every day (unless it rains) for 2-3 weeks. Mother Nature usually takes care of the heavy lifting in the spring…sometimes too well!
  7. Mow after 2-3 weeks, but do so at 3 to 3 ½” so the roots get to go deep. Deep roots will help with drought resistance.
  8. Don’t spray any herbicides until this seed is up and has been mowed twice!

I really encourage spring seeding for shade lawns because we don’t have to deal with the leaves dropping like you do in the fall. Also, you don’t ever have to worry about crabgrass growing in the shade because it won’t grow there. You can use “Tupersan®” where you have seen crabgrass in the past, but it is expensive. I prefer to tell my clients to use Dimension ® pre-emergent after the seeded areas have been mowed twice. You still might get some crabgrass, but nothing that can’t be sprayed out with some inexpensive “post emergent” crabgrass sprays. Dimension ®, in the granule form, will kill small germinated crabgrass plants. Tupersan ® will only keep crabgrass under control if it is applied before the crabgrass germinates. It also requires reapplication in 25 days—expensive and time consuming!


Don’t wait on this project. It’s better to get this done as early as you can. September will be the next and best time (especially in full sun areas) to repeat this process. If you apply crabgrass controls, be sure to rinse out the spreader before using it to spread seed. Grass seed can be killed even by the “dust” of the crabgrass controls.


Try not to apply or do anything to zoysia lawns during March…it’s too early. Remember folks…”it’s just grass”.

Glennon Kraemer owns and operates GR Robinson Seed and Service, has an AAS degree in Horticulture from St. Louis Community Colleges-Meramec, and a BS in Horticulture  from Southern Illinois University-Carbondale. He teaches turf grass classes at SLCC-Meramec, Missouri Botanical Garden and various garden centers. He can be reach at (314) 427-0300.