With winter’s wrath hopefully behind us, it is time to think about spring. Could it also be time to transform lawns from brown and sad to green and luscious? Of course! Proper fertilization, weed control and watering strategies are essential to make this happen.
Early spring is an important time of year to think about grass care, especially care for cool-season grasses, said Jared Hoyle, assistant professor in the Department of Horticulture, Forestry and Recreation Resources at Kansas State University.
“We have had a mild winter, and it seems like we are warming up quickly,” said Hoyle, a K-State Research and Extension turfgrass specialist. “The buds are blooming on the trees, and when I see that, I start to think about what we can do to prepare our lawns for 2016. If we can get on top of things early, we will be on track for the rest of the year.”
Taking care of weeds
Hoyle said weed control is somewhat different for cool-season and warm-season lawns.
“Any of the winter annual weeds like chickweed or henbit that are lingering around can be treated with synthetic auxin herbicides, your typical 2,4-D,” Hoyle said. “It is important that you do not treat warm-season lawns during the transition from dormant to green. This could delay plant growth. Don’t worry about the transitional phase with cool-season lawns.”
Hoyle added that while fall is a more effective time to combat weeds compared to spring, it is best to attempt to exterminate broadleaf weeds before summer and prevent having to deal with them at a later date.
“As it warms up, we look at not only broadleaf weeds but our summer annual weeds like crabgrass and goosegrass as well,” Hoyle said. “Typically in the state of Kansas, our crabgrass inhibitor spray time ranges from April 1 through April 15. Another good time to use the crabgrass preventer is once the forsythias and redbuds begin to bloom.”
Dandelions should be exterminated before summertime. The same herbicides used in the fall can be used in the spring, Hoyle said, but it is important to use those on a day with temperatures above 50 degrees Fahrenheit, as plants need to be growing to absorb the chemicals.
When thinking about weed control, it is also a good time to think about soil fertility.
“Warm-season grasses such as Bermudagrass and buffalograss should be fertilized once they turn green,” Hoyle said. “You can use either a quick or slow release method, and typically it is about a pound per 1,000 (square feet) for the first application. When using a slow release method, you may use more fertilizer to last the whole summer.”
Hoyle cautioned that many popular fertilizers also contain pre-emergent herbicides, so make sure to read the product labels. Weed control should be done around the beginning of April or before the warm-season grasses turn green, which means people should use a product solely for weed control or that contains little fertilizer. Then consider fertilizing the lawn once the warm-season grasses have turned green and started growing.
For cool-season grasses, Hoyle said the “weed and seed” approach can be used, because cool-season grasses start turning green earlier. He still cautioned against using too much fertilizer at one time.
“During the spring, the soil is still cool while the ambient air temperature is warmer,” Hoyle explained. “When we fertilize in the spring, we get a lot of shoot growth, or vice versa in the fall when we fertilize we get a lot of good root growth. If you have too much soil fertility in the spring with cool-season grasses, you get more top growth and not much root growth.”
“This can be disastrous in the dry summertime, where the plant has grown above the soil but hasn’t grown roots,” he continued. “With cool-season grasses, it is important to have a good, healthy root stand to survive summer droughts.”
During the spring when the grass starts to grow, give it some water, but let it stress some to prepare it for potential summer stress, Hoyle said.
“Otherwise if we just continuously water the grass, it won’t grow deep roots for summertime,” he said.
An easy reference point is to give the grass about an inch of water per week, including rainfall, and don’t water daily, Hoyle said. Consider not watering for one or two weeks, as this stress period could be beneficial later. Proper preparation will help the lawn survive better during a dry, hot summer.
More information on lawn care is available at local extension offices or by visiting the K-State turfgrass research, teaching and extension website.