KC Gardens

With a little TLC, your new grass will re-emerge strong in spring

Seedling grass needs mowing, fertilizer and sun (so rake those leaves).
Seedling grass needs mowing, fertilizer and sun (so rake those leaves).

Newly seeded grass is popping up all over the city: Homeowners desperate to get their lawns back into shape have sown bluegrass and tall fescue. Now that that seeding period has come to a close, it is time to turn our attention to getting the new grass established and ready for spring.

Mow properly: New grass is mowed no differently than an established lawn. One common mistake is thinking that the longer the grass grows, the quicker it takes root. The truth is just the opposite: Long, straggly blades fall over, shading and slowing growth.

The mowing height for the bluegrass and tall fescue is 3- to 3  1/2 inches. Mowing shorter or longer could slow the growth.

Continue your usual mowing schedule, and don’t worry about walking on the new grass. It is a good idea to avoid traffic, but normal wear will not slow growth. Continue to mow until necessary, often into November.

Feed to promote growth: Timely fertilization will speed up the establishment of new grass. Usually, a starter-type fertilizer lower in nitrogen and higher in phosphorus is applied at seeding. Constant watering and new growth quickly use up the treatment. When the grass runs out of nutrients, especially the nitrogen, the process slows.

It’s a good idea to make a follow-up application about a month after grass sprouts. Nitrogen, the first number on a bag of fertilizer, is needed in the greatest amounts.

Apply a high-nitrogen lawn fertilizer such as 29-0-0 or 30-3-3. This application will promote rapid growth and thicken up the stand for a nice look. Another high-nitrogen application in mid-November is a good idea, as this provides for additional root growth and early spring green-up.

Control weeds: Cool fall weather provides the ideal conditions for many spring weeds to germinate. Henbit, dandelions and chickweed are the common invaders. Even though these will not flower till spring, fall is the best time to control them.

However, seedling grass needs to develop strong roots and top growth before it can withstand an herbicide application. Products to help eradicate fall weeds require a certain stage of seedling development.

The best way to know for sure if the new grass is mature enough for a treatment is to read the label on the weed control. As a rule, most products can be applied after the newly sown grass has been mowed a couple of times.

Pick up leaves: Don’t let leaves collect over the turf, or you can expect the grass to be dead come spring from lack of sunlight. Plenty of sunshine and a warm fall will keep the grass growing underground long after the mower is tucked away for winter.

The hard part of sowing grass is getting it up and growing. It takes just a little more effort to turn the seedlings into a lush carpet of green.

Dennis Patton is a horticulture agent with Kansas State University Research and Extension. Got a question for him or other university extension experts? Email them to garden.help@jocogov.org or visit KCGardens.KansasCity.com.