At this time of year it takes special care to keep your lawn from drying out.

Most people believe that the only way to insure healthy turf year round is to install an automatic irrigation system, and during the late summer there’s plenty of evidence to support that idea. Lush green lawns in August are rare, and are often kept green with sprinklers.

If cost is no object, and water is plentiful and cheap, this may indeed be the ideal solution, but there are other approaches to consider.

The fact is that grasses are meant to go dormant during the drought months. In nature it’s actually not normal for most grasses to be lush and green all year round. Just because the tops are brown doesn’t always mean the grass is dead. It’s simply resting, waiting for cooler, wetter fall weather.

Different types of grasses react to drought differently, but the key to green summer lawns is the depth of the root system. Shallow-rooted grasses dry out faster.

So, as with most plants, the health of grasses can be improved by encouraging deeper roots. Ideally, lawn areas should be deep-tilled before planting seed (or installing sod), adding peat moss or compost to reduce compaction.

This kind of soil preparation rarely happens in any garden, even your tomato patch, but it should. So how do you improve the drought tolerance of existing lawns?

Here’s my recipe. Twice a year, in spring and again in fall when the soil is moist, core-aerate your lawn with a “plugger”.

First, spread several pounds per thousand square feet of turf-type tall fescue seed, and some fertilizer. 10-10-10 works OK, but a multi-vitamin multi-mineral lawn fertilizer with soil microbes (like Espoma lawn food) is vastly better for depleted soils. (If you use your spreader AFTER the plugger you’ll pick up soil on your feet and the spreader wheels; that’s why you spread first and plug afterwards.)

Now your lawn should be full of holes, three inches deep. The first rain will wash the seed and fertilizer into the holes (along with the soil from the plugs as they break up), ideal moist planting holes protected from compaction, wind and sun.

The moisture will allow deep root penetration as the grass seed sprouts and grows, and the thousands of little plug holes will trap rainwater that would otherwise run off, taking your expensive seed and fertilizer with it.

We’ve found that premium turf-type fescues make the ideal lawn grasses. They form clumps that spread underground, choking out lawn weeds. Turf-type fescues are dark green, perform well in sun or shade, require less frequent mowing than most lawns grasses, tolerate traffic well, and are very drought tolerant.

For people with large yards, maintaining fine turfgrass is a luxury. Only a fraction of our property is maintained as fine lawn, but we have many acres or green grass, and it looks nice even in the drought months because we work WITH nature, not against it as most lawns require.

For over 20 years we have maintained the pastureland on our farm as a nature preserve, allowing the native wildflowers and grasses to mature and cutting only once a year.

The exception has been the trails we cut around the perimeter, and the “lawns” we created by mowing weekly. For the most part we haven’t seeded any new grass, but regular mowing has encouraged the coarse field grasses and white clover.

These remain lush and green in all but the worst drought, because they have extremely deep root systems and little competition from weeds.

Most people object to clover in lawns, but white clover is extremely drought-tolerant and will remain green after most grasses are burnt toast.

Course fescues are unsightly clumps that most homeowners wouldn’t want in their front lawns, however these are tough plants that survive drought and prevent erosion, and they work perfectly well on most of our acres.

One final tip, especially in the dry months: cut your lawn NO SHORTER THAN FOUR INCHES.

This allows the grass to shade itself, maintaining soil moisture, and also discourages weeds.

In the spring and fall you can manicure your lawn a little shorter, but why?

Steve Boehme is a landscape designer/installer specializing in landscape “makeovers”. “Let’s Grow” is published weekly; column archives are on the “Garden Advice” page at www.goodseedfarm.com. For more information is available at www.goodseedfarm.com or call GoodSeed Farm Landscapes at (937) 587-7021.