Planting a spring lawn should start no sooner than it would be safe to set out your tomato transplants, that is, when soil temperatures reach the mid-60s and higher.

This time of the season is the earliest Louisiana gardeners should consider starting a lawn, although you can lay dormant sod during the winter, according to LSU AgCenter horticulturist Dr. Tom Koske.

If you planted sod this past winter, be sure to avoid letting the sod dry out because it doesn't have many roots yet. Root growth will start when soil temperatures are about the mid-60s, but roots will do better as temperatures get above 70 degrees.

Before planting your lawn, have a well-prepared planting bed. This is true for sodding, but especially true for seeding a lawn.

Without the right start, a newly sodded lawn can be an expensive disappointment. Start out by selecting the right type of grass for your needs and the environment that you will grow in. Koske advises consulting the lawn and garden section of the LSU AgCenter Web site or your local LSU AgCenter county agent.

All warm-season grasses can be established vegetatively with sod or grass pieces, but seed-type Bermudas and carpet grass are usually directly seeded. Centipede grass is sometimes seeded as well.

Before laying sod, the horticulturist says, it is important to have a well-prepared soil bed. This means that the soil should be amended as needed for organic matter, lime and phosphorous, then graded for drainage. Never put sod on hard, uncultivated or weedy ground.

Soil needs are best determined by a routine soil test available through your county agent’s office for a fee. Allow two to three weeks for return of test results. Incorporate lime, phosphate and organic matter (if needed) as recommended, to a depth of several inches.

Before laying sod and after amending the soil, install irrigation and establish final drainage grades and contours. Allow grades of 1 percent to 2 percent slope away from the house and plant beds. If you bring in some sandy topsoil fill, first establish a rough grade to accommodate the general drainage flow. If this topsoil is very different from the native soil, lightly till it in to reduce a pronounced boundary between the two very different soil types.

Create swales (depressed areas) if needed to move surface water to drains, or lay field drains with pipe in low areas.

“Figure where the water wants to go, and then help it to do so,” Koske says, adding, “Remember, it is going to go somewhere no matter what, and on our normally heavy soil it won’t percolate down well.”

Lay sod pieces tightly together so edges will not dry out. Where voids exist, shovel in some soil. After planting the sod, it is best to roll it flat to level the sod and press out air pockets that develop in the rooting interface.

If seeding, be sure that the soil is 70 degrees or warmer before planting. In the prepared seedbed, broadcast or drill (drop) the fresh seed. After spreading the seed, be sure to plant it by light raking, rolling or a combination of both.

“Don't allow freshly planted seed or sod to dry out,” Koske says, emphasizing, “This is especially important for new seed, which is trying to develop a sustainable root system.”

Newly planted seed requires light but frequent applications of water to keep the seedlings moist without washing away. Reduce watering as the second and third leaves become visible.

With sod, water less each week until the sod is considered established, which is after the third week. After that, it’s water as needed.

“Get a real good start on your lawn, and hopefully, you won't need to do this again,” Koske says.

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Editor: Mark Claesgens