Watering the lawn and deadheading daylilies: Dan Gill’s advice ahead of a long, hot summer
Home & Gardening

Watering the lawn and deadheading daylilies: Dan Gill’s advice ahead of a long, hot summer

Garden columnist Dan Gill answers readers’ questions each week. To send a question, email Gill at dgill@agcenter.lsu.edu.

We put in a new St. Augustine lawn (Palmetto variety) in mid-May in Uptown New Orleans. It was originally thriving and beautiful, but we are starting to see some browning. We have been watering diligently (30 minutes per day each morning). Do you have any idea what the problem could be? Should we water more or less? Genevieve

Looking at the photo of the grass blades you sent me, I see numerous spots or lesions on the blades of the grass indicating a fungal disease called gray leaf spot. Treat twice with myclobutanil (Immunox and other brands) or anything labeled to control lawn diseases following label directions.

Abundant moisture encourages gray leaf spot to occur, and your watering is likely a factor. Watering too frequently over too long a period will encourage fungal diseases to attack. I recommend watering newly laid sod every day for no longer than 10 days after planting. Then, water every other day for another seven to 10 days. After that, water normally as needed depending on the rain — once or twice a week during hot, dry weather (no rain for seven to 10 days). It’s well past time for you to cut back on watering the lawn daily. 

When daylilies are finished blooming, should the stems (or stalks) be left to dry, or can they be cut back as soon as all of the flowers on the stalk have bloomed out and faded? The same question regarding agapanthus. Debbie

In both cases, cut the flower stalks down at the point where they grow out of the foliage. This can be done when all the flowers on a stalk have finished blooming or soon thereafter. This gardening technique of removing faded flowers and stalks is called “deadheading.” It keeps plants looking fresh and attractive and prevents them from wasting energy making seed pods we don’t need. 

A friend who lives in Lake Charles wants some advice about a magnolia tree. He is wondering if it was affected by the drought last summer. Other trees in his yard are fine. But the magnolia is mostly dead with just a few green branches near the lower trunk. He is wondering if he should cut off the dead top back to the living branches. What do you think? Paul

Yes, the condition of his magnolia tree is due to last summer’s severe drought. Magnolias were hit especially hard by the drought, and magnolia trees died all across Louisiana (I lost a Little Gem magnolia in my yard). Other species of trees were also killed by the drought, including large trees. Now that it is hurricane season, get these removed as soon as possible.

Unfortunately, the magnolia tree will never recover, and so it should be considered for removal. Since the lower parts are still alive you could try cutting off the dead upper parts back to the parts that are still alive and give the tree a few years and see what happens. But the results likely will not be satisfactory, and it would really be best to let it go and remove it.

I’m getting some conflicting internet information about the male flowers on burpless cucumbers. Should I cut off all the male flowers in order to have higher quality cucumbers? Sharon

I’ve never heard of having to remove male flowers to have quality burpless cucumbers. My guess would be that you will get no cucumbers at all without male flowers to pollinate the females.

Garden tips 

Pampas grass is one of the few ornamental grasses not going dormant this time of year. PHOTO BY SAM DES BORDES

TOUGH AND ATTRACTIVE: Ornamental grasses are an excellent choice for gardeners trying to introduce more drought-tolerant, pest-resistant plants into their landscapes. There are many types suitable for virtually any landscape situation. Even though it is hot right now, ornamental grasses are so tough you can plant them through the summer months.

NEW PLANTINGS: We do not expect most spring-planted vegetables, like snap beans, cucumbers, squash and tomatoes, to grow and produce through our long warm growing season from March to October. When they are finished producing and you remove them, you could simply rake the area level and apply a four- to six-inch layer of mulch to prevent weeds until you decide to plant again. But you may also decide to rework the beds and plant heat-tolerant summer crops, like okra, Southern peas (purple hull, black-eyed peas, crowders and others), peanuts, hot peppers or yard-long beans, to name a few. 

PEACH TREE TLC: Spray peach-tree trunks thoroughly with permethrin to prevent the peach tree borer from getting into the trunk and causing damage. Repeat again in mid-July and mid-August.