A butternut squash with a split. Photo: Christy Frederic, Master Gardener.
Christy of Pineville has a fall garden and saw an issue of concern, “This is one of several lovely butternut squashes I have growing on vigorous vines. [I] Noticed this split today! [I] Would like to prevent more of this happening on the other squashes...!!!!” AHA suspected surplus moisture, but consulted with Dr. Kiki Fontenot, the Vegetable Specialist with the LSU AgCenter.
Dr. Fontenot promptly replied and shared her insights, “This could be two problems. The first is like you said, too much water as the skin is starting to harden. This squash is not ready to harvest yet because the stem is still too green. It should look drier. The other factor is applying fertilizer too late in the season. When I plant a late crop of squash, I usually put in all the nitrogen pre-plant. But if I only put in the normal amount, I would side dress as the crop starts to vine and not after that. Too much nitrogen applied later in the season can cause cracking. So, turn off irrigation and stop fertilizing and hopefully the rest will be fine.”
A green caterpillar of the imperial moth. Photo: Todd Burnaman. Dry Creek Baptist Camp.
Todd of Dry Creek sent a text of concern regarding a caterpillar, “Should we be concerned about an infestation of imperial moth caterpillars...? [We] have 5 of them show up today at Dry Creek Baptist Camp... [This is the] first time I’ve ever seen them.”
Todd correctly identified this insect as the caterpillar of the imperial moth. AHA was unfamiliar with this particular caterpillar so he did a little research and learned from Rebecca Jordi of University of Florida Extension, “It really does not do enough damage for us to worry about trying to control it. The imperial moth is found from southern New England south to the Florida Keys and west through the southern Great Lakes region to eastern Nebraska and central Texas.”
AHA also checked to see if this caterpillar has venomous spine, and it does not so he advised Todd, “[I have] no concern about tree damage or venomous spines. The birds will thank you for leaving them.”
Todd texted back, “Thanks very much! They’ll be chicken snacks.”
Common boneset. Photo: LaDonna Millender, DeRidder, LA.
LaDonna of DeRidder sent an email simply asking, “So what do you think this weed is?”
AHA consulted with Kerry Heafner, an AgCenter Extension Agent and botanist, about the name of this plant, and it is called common boneset. This plant is a perennial plant blooming in the fall. According to the Lady Bird Wildflower Center, this plant attracts many native bees. It also “attracts predatory or parasitoid insects that prey upon pest insects.”
Parts of crabgrass. Trey Geymann, Master Gardener.
Trey wanted to identify grass in his landscape, “I’ve attached two photos of a grass species. I am curious if you can tell me what it is. I have been calling it crab grass. I till it in the compost when I plant, and this grass is always the first thing to get established on the bare soil. [It] has a blue tint.”
Trey correctly identified this grass as crabgrass. The Louisiana Home Lawn Series: Crabgrass recommends these practices to control crabgrass in the landscape, “The best way to prevent or reduce weed encroachment is to maintain a healthy lawn through proper fertilization and soil pH and regular mowing. Properly maintaining a lawn through these cultural practices promotes dense and vigorous turfgrass, allowing it to better compete with weeds. Below are the recommended mowing heights and nitrogen fertility rates recommended per turfgrass species. In addition to these lawn care practices; manual removal of weeds may also be necessary.
|Turfgrass||Mowing height||Nitrogen Rate (per 1,000 ft2/year)|
|Bermudagrass||1 - 2 inches||2 - 3 pounds|
|Centipedegrass||1 - 2.5 inches||0.5 - 2 pounds|
|St. Augustinegrass||2.5 - 3 inches||1 - 3 pounds|
|Zoysia||1 - 2.5 inches||0.5 - 2 pounds|
In addition to cultural practices, herbicide applications may be required to achieve effective weed control. Pre-emergence herbicides are heavily relied upon for crabgrass control in turf. These types of herbicides prevent the emergence of crabgrass plants from the soil, but timing of these applications is highly important. It is critical that these types of herbicides are applied prior to crabgrass germination. Crabgrass germinates when soil temperatures warm to approximately 60 degrees Fahrenheit. Depending on the severity of the winter, pre-emergence herbicides should be applied as early as late January in the New Orleans area to late February in the Shreveport area. Post-emergence herbicides are available, but these herbicides are more effective when applied to young (fewer than two tillers) crabgrass.
When applying any type of herbicide, you must follow the manufacturer’s labeled directions.
For more information regarding pesticides for turfgrass, please reference the Louisiana Suggested Chemical Weed Control Guide at the LSU AgCenter website www.lsuagcenter.com .
If you want to contact Roots, Shoots, Fruits and Flowers, please send your questions and pictures to Keith Hawkins, Area Horticulture Agent (AHA), 337-463-7006 or email@example.com. Also, you can be on the “green thumbs” email list by emailing your request to the address above.
“Before you buy or use an insecticide product, first read the label, and strictly follow label recommendations. Mention of trade names or commercial products in this article is for informational purposes only and does not constitute endorsement by Louisiana State University AgCenter.”
“This work has been supported, in part, by the USDA National Institute of Food and Agriculture, Renewable Resources Extension Act Award, Accession Number 1011417.”