Karol Osborne | 11/13/2018 5:37:00 PM
(11/13/18) WINNSBORO, La. — Shifts in product availability and consumer perception affect soilless substrate components such as peat moss and pine bark used in many landscape and garden potting mixes and mulches, said LSU AgCenter commercial horticulture specialist Jeb Fields.
Fields was among several AgCenter experts who spoke to a group of nursery representatives, landscapers, home gardeners and Louisiana Master Gardener volunteers at a horticulture forum held Nov. 7 at the LSU AgCenter Scott Research and Educational Center in Winnsboro.
“The container substrate influences every decision you make,” Fields said, adding that many components are available in commercial potting soils or for making your own.
Public opinion, availability and sustainability issues have spurred increased interest in finding alternatives to traditional soilless substrates, Fields said.
“We are starting to see more wood substrates in the commercial greenhouse industries, while nurseries primarily use pine bark because it is readily available and provides the least costly uniform material for large containers,” he said.
Coconut coir is also catching on, Fields said, adding that it has similar characteristics to peat moss in water absorption and nutrient transfer.
AgCenter weed scientist Ron Strahan said homeowners have more options than they are aware of to break the cycle that allows weeds to reproduce and increase seed banks in flower garden soils and mulch.
“Many homeowners aren’t using preemergence herbicides, but they are effective tools that can break the cycle of continuous weed seed production and help deplete seed reserves,” Strahan said.
For most broadleaf weeds like spurge and common purslane, mulch used in conjunction with preemergence herbicides are the only selective control option available, Strahan said
“We offer plant pathogens a free buffet,” AgCenter plant pathologist Raj Singh said, referring to Louisiana’s longer growing season, hot and humid weather conditions and wide array of fungal and bacterial pathogen populations.
Effective integrated pest management uses different strategies that begin before planting and continue through and after the life of the growing system, Singh said.
Keeping plants stress-free is key to boosting their healthy immune systems and reducing susceptibility to disease and insect pests by focusing on early and accurate identification of plant pathogens and pests, he said.
“The label is the law,” Singh said. Using chemicals requires understanding the chemical label, including dose recommendations and application frequency.
“Now is a good time to get your soil tested,” said AgCenter horticulture agent Kylie Miller. “Look at soil pH and make necessary soil amendments.”
Soil test kits are available from all AgCenter parish extension offices. Fees begin at $15 for the first sample and are $10 for each additional sample.
AgCenter vegetable specialist Kiki Fontenot shared top varieties from research trials on cabbage, Brussels sprouts and tomatoes.
“In the spring you can grow your heirlooms, hybrids and whatever you want. But if you are growing outdoors, the tomato spotted wilt virus-resistant varieties are your insurance against thrips,” she said.
AgCenter horticulture agent Kerry Heafner offered seed-sowing tips and discussed techniques used in germinating seeds, including cold storage and scarification or weakening and breaking the seed open.
“Seed coats can be as thick as a coconut shell or as paper thin as on a peanut, so how we penetrate that seed coat is key to getting the seed to germinate,” he said.
“Always use fresh seeds, and always do your homework on variety selections,” Heafner said, adding that planting depth, planting medium and watering are important for effective germination.
For fruit growers, variety selection should be based on adaptability for the location, site preparation and management plans, AgCenter horticulture agent Carol Pinnell-Alison said.
Size matters in fruit tree selection, she said. Growers should look for smaller trees that can be started early and pruned to train the tree structure.
AgCenter Northeast Region director Melissa Cater said expansion efforts are underway at the Scott Center to increase educational and outreach efforts highlighting horticulture-related programs.
“We are in the planning stages for establishing various demonstrations on the station and want to enhance Louisiana Super Plant promotion,” said AgCenter horticulture agent Donna Lee.
AgCenter weed scientist Ron Strahan suggests strategies for battling common weeds in Louisiana gardens at a horticulture forum held Nov. 7 in Winnsboro. Photo by Karol Osborne/LSU AgCenter