With daffodils, dogwoods, and forsythia in bloom, homeowners get the itch to spend some time in their yards. The following are some do’s and don’ts for spring lawn care on cool-season grasses (tall fescue, Kentucky bluegrass) in Kentucky.
Do: Get your Mower Ready for the Season!
• Having your mower ready to go before the season starts will save you downtime during the growing season.
• Sharpen blade. Having sharp mower blades are very important to turf aesthetics and
health. To learn how to sharpen your blade, check out this video: https://www.youtube.com/watch?v=JMy1j9NR89o&list=UUMFY6zEWe6uJEYakzOofhIg
Don’t: Apply Nitrogen.
• The vast majority of nitrogen fertilizer should be applied in the fall. Fall applications
improve the health of the lawn and result in a greener lawn in the winter, less spring
mowing, and less weeds, heat stress, need for water, and disease problems in summer.
• Nitrogen applied in spring and summer promotes growth of warm-season weeds such as crabgrass, goosegrass, and bermudagrass. Further, high amounts of nitrogen in spring
and summer can result in increased damage from white grubs in the soil. Adult beetles
are attracted to the lush lawns and high nitrogen levels restrict turf rooting which
compounds the damage from the white grubs feeding on the turf roots. More
information on fertilizing lawns can be found in this video:
Do: Apply a Pre-emergent Herbicide.
• Annual grassy weeds such as crabgrass and goosegrass begin to germinate in the spring
and depending on the thickness of the lawn, the amount of weed seed in the soil, and
the environmental conditions, untreated populations of these weeds can out-compete
and take over your desired lawn species. By applying a pre-emergent herbicide prior to
weed germination, weed numbers can be drastically reduced and your lawn can have
the chance to flourish without fighting weeds for space, nutrients, light, and water.
• In western Kentucky, a pre-emerge herbicide should be applied prior to around April 7.
In central and eastern Kentucky, the spray before date is usually around April 15.
• A pretty good indicator plant for knowing when to apply a pre-emergent herbicide by is
forsythia. Generally, a pre-emergent application should be applied before forsythia
drops its blooms (Figure 1).
• Do not apply weed and feed products as we don’t want to be applying nitrogen to our
cool-season lawns in the spring.
• If you miss the pre-emerge window, and weeds begin to germinate, your best bet is to
apply a post-emergent application to small seedlings as most pre-emergent products do
not work after germination. For more information on controlling weeds in your lawn,
check out the following publications:
Don’t: Seed in the Spring.
• The best time of year to seed lawns is in the early fall. The concern with planting in the
spring is that there is significant competition between seedlings and grassy weeds (and
weeds almost always outgrow our desired species) and the immature seedlings can
struggle with summer heat and drought more so than a mature lawn.
• If you have to seed in the spring, plant around the time that forsythia is in bloom (Figure 2), as soil temperatures are adequate at this point for germination of tall fescue or Kentucky bluegrass.
• For more information on establishing or renovating lawns, see:
Do: Mow at Regular Height.
• Once the grass starts to grow in the spring, it will really start to take off. We see most of
the growth in the spring of the year, it slows down in the summer, and then ramps up
again in autumn (Figure 2).
• Because the grass grows at a high volume in the spring, it’s best to not let the height get
too long before mowing. Ideally, never cut off more than 1/3 of the leaf in one mowing.
For example, if you want to maintain your lawn at 3 inches, mow when the height
reaches about 4.5 inches. Removing more than 1/3 of the leaf blade results in a
reduction in root growth.
• Mowing at taller heights has been shown to reduce crabgrass populations without the
use of herbicides. Recommended heights for lawn grasses in Kentucky are:
o Tall fescue 3 inches or taller
o Kentucky bluegrass 2.5 inches or taller
• For more information on mowing your lawn, see the following publication:
By following these basic do’s and don’ts, you can start your lawn off on the right foot this spring and enjoy it more and work on it less throughout the year.
Source: Dr. Gregg Munshaw, Turfgrass Extension Specialist, University of Kentucky