December marks the start of strawberry harvest season in south Louisiana.
“Louisiana strawberries are delicious whether produced on a Louisiana farm or in your backyard,” says LSU AgCenter fruit and vegetable specialist Kiki Fontenot. “Fresh-picked berries that have fully ripened on the bush are amazing.”
If you’re growing strawberries at home, knowing your weed management options is essential, Fontenot says.
For strawberries planted between September and mid-November, gardeners still have plenty of time to initiate a good weed management plan. Black plastic mulch is very effective in both keeping berries clean and preventing weed infestation.
Other choices include leaves, pine straw and shredded newspaper.
If you have applied a thick-enough mulch layer, pulling weeds by hand shouldn’t be too big of a chore. Mulch also does more than hold down weeds; it keeps the fruit off bare ground.
“Fruit that develops in contact with soil will rot,” Fontenot says.
She recommends at least 4 inches of mulch, adding that extra-thick layers of pine straw have another benefit in that they can be raked over plants when temperatures drop below freezing to provide a degree or two of protection. And, she says, many gardeners claim that raking pine needles over red berries helps camouflage the fruit from garden thieves such as birds and squirrels.
For gardeners who insist on using herbicides, chemicals labeled for use in and around strawberries are really limited.
Corn gluten meal packaged and sold by Preen is one of the only preemergent herbicides available to home gardeners. This product is organically labelled, but can be used only after strawberry plants are established in the garden and are at least 3 inches tall.
Once weeds break through the initial barrier of mulch and preemergent herbicide, gardeners have two chemical options.
Grasses can be controlled by spraying sethoxydim, a selective herbicide that only kills grasses. Applying sethoxydim over the top of the plants will not injure the berries.
If you have both grasses and broadleaf weeds, you can apply pelargonic acid, sold primarily as Scythe. This is an organic herbicide that will knock back annual weeds but requires several applications to kill perennial weeds.
Because pelargonic acid is non-selective, it will kill or injure both broadleaf and grass plants — including strawberries.
“Be very careful not to spray it on the berry plants,” Fontenot cautions. “Rather, use it in the row middles or around plants.”
As always, read and follow all label directions on garden chemicals.
Got a gardening question? Write to GardenNews@agcenter.lsu.edu.