What a “winter” we’ve had! In 32 years of caring for lawns in Oklahoma, I”ve never seen as much green bermudagrass in mid to late March as I’m seeing now. Seems that with all the global warming talk, it’s being verified here right before our eyes with pushing the lawncare season up by weeks. With the warm spring weather, many folks are firing up their mowers and out scalping their lawns. We always discourage this due to the higher likelihood of winterkill on bermudagrass.
It’s Oklahoma, so if it’s 90 degrees today, it could be freezing a few days later. That’s our concern. Typically, we can still have a hard freeze before April 15th, and we are still over 3 weeks away from being there. So don’t let this warm spring fool you, we could still be in for cold weather. And if the bermudagrass is too green and growing then, an April freeze even in the high 20’s could severely damage or even kill bermudagrass.
Bermudagrass is a warm-season turf, and goes dormant in late fall through winter to protect the crown and topgrowth from cold damage. As the weather warms the soil, new growth will grow from the crown at the base of the plant, sending new green stems and leaves up from the ground. The root system is also re-generating at this time, sending new roots into the soil. By scalping the turf down with mowing at a very short level, the soil is exposed more and warms up quicker, leading to more shoot growth. And scalping also removes that thick insulating layer of brown grass, which protects the crown and root system from sudden temperature drops.
Therefore, we strongly advocate waiting until after the freeze date of April 15th before scalping your lawn in Oklahoma. It’s fine to mow at a 2″ level or so just to clean it up or remove any weeds. Just don’t take it down the ground. Leave that “blanket” of turf on until the chance of a freeze is over. I’ve experienced a few years when the bermudagrass greened up early like now, only to have a hard freeze during early April whack it back so much that the turf really did not fill in until late May. So if you’re anxious to get out and enjoy the warm weather, go ride a bike, plant a tree, plant your garden, anything other than scalping your bermudagrass now. And never scalp fescue, or you may just kill it!