In the Garden with Kerry Heafner: Warm Weather Gardening

article by Kerry Heafner, LSU Ag Center

Warm weather gardening kicks into high gear during April! Both vegetable gardens and ornamental beds will take off and hit their strides for May. If you’re just now getting started, don’t worry. You still have time!

As cool-season annuals finish up this month, start looking for warm weather replacements. Start with varieties designated as Louisiana Super Plants by the LSU AgCenter! If your full-sun areas need bright color, lemon sedum, marketed as both ‘Lemon Ball’ and ‘Lemon Coral™’ sedum, is a 2019 Super Plant selection. The texture of any succulent is eye-catching, and lemon sedum is exceptional. Drought resistance and heat tolerance make it a go-to for our summers, especially in xeriscapes or rock gardens. It also makes a great “spiller” in container plantings and is very effective as a mounding ground cover. Lemon sedum should be treated as an annual in our region but may be cold hardy during mild winters.

If you’re looking for shrubs for areas that get sun all day, try ‘Sunshine’ ligustrum. Also called ‘Sunshine’ privet, its brilliant chartreuse foliage provides a striking contrast to most other colors, from dark backgrounds like brick walls to reds and pinks in the foreground. ‘Sunshine’ ligustrum is a sterile cultivar. There is no chance of it becoming invasive and no allergy issues! It can be pruned to stay under three feet or may be allowed to get six or seven feet tall if more height is preferred. Brilliant color and versatility are yours to be had with ‘Sunshine’ ligustrum!

Lawns will need some attention this month. Remember, our Deep South turfgrasses (Bermudagrass, carpetgrass, centipedegrass, St. Augustinegrass, and zoysiagrass) are not adapted to deeply shaded areas so full sun is key for a lush, healthy lawn. A fungal problem called brown patch may be noticeable due to recent wet weather. Yellow areas that eventually turn brown and increase in size concentrically are likely brown patch. Brown patch is exacerbated by overzealous watering, especially where soils are compacted. Frequent-enough rains render religious irrigation of established, residential lawns unnecessary. During dry periods, when irrigation is necessary, the LSU AgCenter recommends less frequent, deep watering rather than frequent, shallow watering. Brown patch is easily treatable with products containing either myclobutanil or propiconazole along with adjusting your watering regimen. Always read, understand, and follow the directions on the label of any pesticide, whether it’s an herbicide, insecticide, fungicide, or other product. Pesticide labels are legally-binding documents. Keeping lawns well-aeriated is also recommended.

Lawn mowers should be serviced and ready to rock and roll! Adjust the blade to the height appropriate for your turfgrass. Bermudagrass, carpetgrass, centipedegrass, and zoysiagrass should all be mowed at 1 to 2 inches. St. Augustinegrass should be mowed to 2.5 to 3 inches.

In the veggie garden, get beans of all kinds started this month. Remember, with legumes, a highly fertile soil isn’t necessary. Beans and peas have their roots colonized by a bacterium that converts atmospheric nitrogen into useable nitrates for the plants. They make their own fertilizer!

Sweet corn can go in this month if March was too wet. If you’ve never boiled and eaten an ear of sweet corn right out of the garden, you’ve missed out! Sweet corn needs space, full sun, and is a heavy feeder so get ready to fertilize generously. A pre-plant fertilizer application of about 1.5 pounds of either 8-24-24 or 13-13-13 per ten foot row is recommended, followed by side-dressing every two weeks with 0.5 pounds of calcium nitrate per ten foot row. Sow two or three seeds in groups about eight inches apart, thinning each hill to the strongest stalk. Plant in multiple, short rows rather than in one long row. Corn is a wind-pollinated grass and the block-style planting ensures adequate pollination. The tassels are the male flowers and provide pollen. The ears are female flowers and their characteristic silks are the stigmas and styles (where the pollen from the tassels should land.) There is one silk for every kernel on the cob. Sweet corn is ready to pick when the ends of the silks turn brown. Yellow varieties for our region include ‘Seneca Horizon,’ ‘Gold Queen,’ and ‘Haney Select.’ White varieties recommended are ‘8101 Summer Sweet’ and ‘Silver Queen.’ A number of heirloom varieties are available from reputable seed companies.

Summer squash and cucumbers can be planted this month. Seeds of both can be started either directly in the garden or in cups for transplanting as soon as the first true leaf is visible after the two large cotyledons emerge. Both are also heavy feeders and do best with generous servings of compost added to planting holes. Take your pick! Zucchini, yellow crook neck, yellow straight neck, or patty pan squash will all produce heavily. I prefer the scalloped or patty pan varieties based on flavor alone. Cucumber varieties to try include ‘Dasher II,’ ‘Thunder,’ and ‘Straight 8.’ ‘Calypso’ is a good variety for pickles, although even slicers make great pickles if harvested at the right size. I find ‘Marketmore’ to be reliable, prolific, and versatile for slicing, pickling, or for fresh eating. Cucumber vines will need a trellis to climb on, which can be made of just about anything from bamboo poles and jute string to various wire structures. Trellising vines will yield cleaner, straighter cukes and make the yellow flowers more accessible to pollinators.

Tomato transplants should be set out this month and the earlier the better. As with squash and cucumbers, tomatoes benefit from compost being added to the planting hole with the addition of a handful of pelletized gypsum (calcium sulfate) to keep blossom end rot (BER) at bay as fruit develop. Set tomato plants deep to ensure the development of large, healthy root systems. Hot weather interferes with tomato pollination. This is why production slows or even stops at the height of summer. So, the sooner tomatoes are planted out the sooner you’ll be harvesting. Botanically, tomatoes are vines, so either stake or cage plants to support vertical growth, or allow them to run on the ground over a layer of straw or hay mulch. Mulch will be necessary to control soil-borne fungi that are spread by splashing rain drops. Indeterminate varieties like ‘Better Boy,’ ‘Big Beef,’ ‘Creole,’ and ‘Sweet Million’ will need plenty of space for vining. Determinate varieties like ‘Amelia,’ ‘Bella Rosa,’ and ‘Celebrity’ will reach a certain size and produce only a certain number of fruit.

Let’s check the calendar!

• April 3rd, Northeast Region Spring Horticulture Forum at the LSU AgCenter Tom Scott Center in Winnsboro. Registration begins at 8:30 a.m. Speakers will be Dr. Allen Owings, Dr. Kiki Fontenot, and LSU AgCenter horticulture agents.

• April 6th, Northwest Louisiana Master Gardeners spring plant sale. 8:00 a.m. Randle T. Moore Center, 3101 Fairfield Ave., Shreveport.

• April 6th, Briarwood Spring Picnic at Briarwood Nature Preserve. Tickets may be purchased online at https://briarwoodnp2019.bpt.me/. Briarwood is located at 216 Caroline Dorman Rd., Saline.

• April 12th, 29th Annual Garden Symposium at the Biedenharn Museum & Gardens. Speakers will be Harvey Cotten, Dr. Allen Owings, and Julie Spear. Registration required. Call (318) 387-5281 for information.

• April 13th, Northcentral Louisiana Master Gardeners spring plant sale. 9:00 a.m. Ruston Farmer’s Market, 220 E. Mississippi Ave., Ruston.

For advice on how to make your garden thrive, go to the Ag Journal page at www.myarklamiss.com and submit your questions.I’ll answer them every Tuesday on Louisiana Living!