By LSU AgCenter Horticulturists Dan Gill, Kyle Huffstickler and Allen Owings
The end of May means summer is here, even though summer does not “officially” begin for a few more weeks.
Summer in the Louisiana landscape usually begins in May and can run through October. We have many activities to keep in mind during this four- to five-month busy time in the home landscape. Keep all of the following items in mind to be more successful in your landscaping efforts.
Control thrips, aphids, cucumber beetles and spider mites on roses by using a recommended insecticide or miticide. There have been an abundance of insect problems with roses so far this year, so monitor your plants and take care of harmful insect populations before their numbers increase. Also on roses, continue blackspot control by using a recommended fungicide at seven- to 10-day intervals.
When irrigating this summer, water the soil area thoroughly. Try to irrigate less often, but irrigate well each time. Light, overhead sprinkling is not the best way to water.
Continue to plant warm-season bedding plants. Our spring Louisiana Super Plants (Serena angelonia and Butterfly pentas) are hot-summer survivors and can continue to be planted throughout the summer.
Lantanas can still be planted. They thrive in Louisiana’s hot summers. Try lantanas in containers where their drought tolerance is an advantage. Watch for lace bugs on lantanas. If your established lantanas are not performing well, prune and fertilize them. They do best in full sun and under limited irrigation.
Dig and store gladiolus corms in a well-ventilated, freeze-proof place for planting next spring. Gladiolus perform well for us February-May. It is normally too hot and humid in summer for gladiolus to perform well.
Plant sunflowers during late summer for fall flower arrangements. Flower colors include yellow, orange, red, bronze, white and combinations of these. It usually takes about 60 to 80 days from sowing seed until first flower color.
Prune azaleas no later than mid-July. Pruning azaleas after early to midsummer may remove next season’s developing flower buds. This applies to many spring-flowering shrubs as well as hydrangeas and gardenias.
During early summer, gardenias may have aphids, whiteflies and the associated black sooty mold. For optimum plant performance, control the insects with the insecticide acephate or a summer horticultural oil spray.
Camellias and azaleas need care to set a good crop of flower buds for next year. Healthy, vigorous plants will set buds, but weak plants may not. If plants lack vigor, fertilize them, provide moisture during stressful periods and control pests. Remember that these acid-loving plants may have problems if soils are too alkaline. Submit a soil sample to your parish LSU AgCenter extension agent if you are unsure of your soil situation.
Louisiana irises are semi-dormant during late summer. Prune off seedpods and yellow or brown foliage to help keep the plants more attractive. You may transplant or divide Louisiana irises beginning in August.
Cut faded flowers from flowering annuals and perennials to encourage new growth and more flowers. Old blooms and seed heads left on the plants can retard flower production.
These are just a few things to keep in mind as you garden over the next month or two.