Roots, Shoots, Fruits & Flowers: Trifoliate Orange, Milkweeds, Sprag, and Skinks



Trifoliate Orange

Samantha brought in a thorny branch and a fruit resembling a small lemon and wanted to identify the plant. She brought in parts from a plant called trifoliate or sour orange. Dan Gill, retired AgCenter horticulturist, shared these notes about this plant, “The citrus trees you purchase at the nursery have all been grafted. That is, a desirable, named citrus variety, such as Owari satsuma or Meyer lemon, is grafted onto a rootstock that is a completely different type of citrus. Trifoliata orange (also called sour orange) is often used as the rootstock.”

“Once you have located the graft union on the trunk, you must never allow any shoots to sprout and grow from below the graft union. These shoots are called “suckers.” If you let these vigorous suckers grow, you are allowing something that is not your desirable citrus variety to grow. When a citrus tree produces atypical fruit, it generally means the rootstock has been allowed to sprout and grow. The trifoliata rootstock produces poor quality, seedy, sour, round yellow fruit…. The growth from the rootstock often has different shaped leaves from your citrus and is thornier (although, many desirable citruses do produce thorns).”



Harvey asked a simple question, “Do we have milk weed in our area? I have not [identified] any at my place.” Yes, a search online found a self-taught entomologist who works on conservation of the monarch butterfly by growing milkweed species. According to this person on , there are nineteen species of milkweed in Louisiana. Some milkweeds like wet sites like the aquatic milkweed and the swamp milkweed. Others like upland site like the longleaf milkweed and the pineland milkweed. There are quite a few seed companies online selling milkweed seed so if you want to help the monarch butterfly, look up those companies. Finally, the LSU AgCenter has a publication entitled, “Butterfly Gardening for Louisianans” and it can be downloaded from .
Nancy send this email and asked, “My yard is being invaded by a weed called sprag. Is it possible to get rid of it? It seems to be everywhere.” “Sprag” is a new name for AHA so he is not sure what it is but found a plant called “sprague” online. Dr. Ron Strahan, the AgCenter’s weed specialist, is also unfamiliar with this plant. However, if this weed has broad leaf and is growing in a lawn, there are herbicides capable of killing broad-leaf weeds and still safe for grass. Herbicides with 2,4-D or with atrazine are safe to use on lawns while controlling the broad-leaf weeds.



Nancy also sent this question, “…this year I am seeing lots of blue tailed skinks. Are they new to the area?” A professional ecologist with the US Geological Survey confirmed that the five-lined skink is a native lizard in all 64 parishes of Louisiana including urban and suburban sites. They are very common and have no special legal protection. Juvenile skinks tend to have the bright blue tails which diminish with age. Skinks will “eat almost any insect, spider and other invertebrate species they come across.”

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 Also, you can be on the “green thumbs” email list by emailing your request to the address above.

“This work has been supported, in part, by the USDA National Institute of Food and Agriculture, Renewable Resources Extension Act Award, Accession Number 1011417.”

10/29/2019 8:36:11 PM
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