Q: We have had our lawn tested for an apparent disease two years in a row - diagnosis: Leptosphaerulina leaf blight. In the spring and fall when reseeding it comes back beautifully, but by mid-May through Sept. the lawn looks like a horrible straw, then goes almost dead right back to the dirt. We have had our home for many years, and have always had a wonderful lawn. We are told there is nothing we can do for this. Can you help? K.D. - Georgia

I'm assuming that whoever gave you the diagnosis of Leptosphaerulina fungus was correct. This fungus can also be confused with several other similar looking diseases.

Leptosphaerulina fungus over seasons in dead grass tissue. The microscopic spores are produced and released in warm, wet weather and are blown, splashed, and transported on shoes and mowing equipment to healthy grass leaves. The spores germinate and penetrate the leaf blades in a film of moisture.

No fungicide applications are normally needed. You need to provide good surface and subsurface drainage when establishing a new turf area. Test the soil reaction (pH) and follow the recommendations in the soil report. Grow locally adapted and disease-resistant grasses in blends or mixtures. Purchase only quality certified sod, sprigs, plugs, or pathogen-free seed from a reputable dealer. Plant at suggested rates in a fertile, well-prepared seedbed. Fertilize according to local recommendations and soil tests. Recommendations will vary with the grasses grown and their use. Adequate to high levels of phosphorus and potassium (potash) may help to suppress the diseases development.

Do not apply fertilizer during periods of drought or high temperature. Also, avoid excessive early spring nitrogen applications. The resulting lush growth from the excess nitrogen is very susceptible to infection.

Mow frequently at the height recommended for your area, season, and grasses grown (1-1/2" — 2-1/2" for lawn-type grasses and 1/4" or slightly less for fine Bentgrass turf). Remove no more than one-third of the leaf height at one cutting. Keep the mower blades sharp and do not mow when the grass is wet.

Water established turf thoroughly during droughts. Moisten the soil to a depth of at least 6 inches at each irrigation. Repeat every 7 — 10 days if the weather remains dry. Water as infrequently as possible to allow gaseous exchange between soil and atmospheric air. Avoid light sprinklings, especially in late afternoon or evening during cool periods.

Increase light penetration and air movement to the lawn area and speed drying of the grass surface by selectively pruning or removing dense trees, shrubs, and hedges bordering the lawn.

Eliminate foot and vehicular traffic by putting in walks, fences, shrubbery, patios, parking areas, and so on.

Follow suggested insect and weed control programs for the area and grasses being grown. Insects commonly transmit disease-causing fungi or provide entry wounds for them, while weeds may harbor pathogenic fungi.