Repairing dead patches this Spring? Here's how

Here are a couple pictures of a couple different properties that I visited in the past month. As I've mentioned in previous posts, we here in Iowa were hit hard by a drought last summer and here are some of the effects:

 As you can see, there is some work to do.  If your lawn resembles these pictures, you have two approaches to consider. If there are large areas like this and a lot of it, I'd recommend core aeration followed by over-seeding. If you have a couple patches like this, you can do patch seeding where you rake up the dirt and apply the seed. If not protected by shade you want to apply a thin layer of dirt to protect the seed from direct sunlight (which will dry out the seed quicker, making your over-seeding efforts useless).

As far as the large areas you can choose either a rotary or drop spreader. Another option which in which you may achieve better results is by using a slit seeder, this cuts a line in the ground and drops seed into those "slits" and puts seed in direct contact with the soil.

(NOTE: If you're going to seed this in the spring avoid putting down pre-emergent or wait at least 3 weeks after pre-emergent was applied. Also, the longer you wait, the warmer the days get and more water will be needed to establish seed growth)

 
 1. Seed selection: Proper seed selection is crucial, don't just grab a bag of seed and call it good. Different seeds grow better in different environments.  -

Kentucky Bluegrass - This is most common grass used in Iowa, but does not perform well in shaded areas. Bluegrass is not a drought tolerant grass, so it does need watering. You want the soil to be moist, not soggy, but it does require water maintenance. Mowing Bluegrass can be done at 2-3 inches, never cut more than a 1/3 of the blade at a time. 

Fine Fescue - (creeping red fescue, chewing fescue & hard fescues) For shady areas in Iowa you want a fine-leaf fescue or at least a blend that has at least 50% fine-leaf fescue. Fine fescue is more drought tolerant so it doesn't require as much watering, only when severe water deprivation. Over-watering, especially in humid regions can lead to disease. Fertilizing will green up the lawn, but do not fertilize in the summer months and watering is needed when the soil dry.

 2. Rake up the soil to remove dead grass (or core aerate in larger areas). The seed needs to make contact with the soil in order to grow. If the areas is exposed to direct sunlight, then you want to cover with a thin layer of topsoil.

3. Apply a starter fertilizer, this will assist in kick-starting the growth of your seed.

4. You want to water 2-3 times a day for 2-3 weeks. When grass seed is growing you can cut back on the watering, but you will want to continue to water until the seed is established.

After a few watering's your seed shouldn't be floating anymore, so it will be safe to mow. You want to mow frequently and shorter 1 1/2-2 inches so the seedlings aren't fighting for water. Once your new grass reaches 1 1/2-2 inches you can increase your mowing height to 2 1/2-3 inches. Do not bag clippings, you want to have a self-mulching mower blade and the grass clipping provides good nutrients for your lawn.

As far as fertilization, 6 weeks after germination you can resume your fertilizer treatments (as long as those 6 weeks doing bring you into Mid/Late July or August).