Cannas, Potato Plants and Millipedes

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Golden Lucifer canna


Recently, AHA asked Master Gardeners to share a mistake made in the garden or in the landscape. Cyndi of Marksville said, “I was given 2 Yellow Cannas, so got home eager to plant them. Keep in mind I live in the swamp, so the only colors I have are green and brown. I was so excited to have a bright yellow to add to my very small yard. Back here we flood often, so I'm very limited to planting space. I carefully looked and found 2 different spots to plant 1 Canna. Well, the following year I had 6 in each spot, the 2nd year I had at least 20 in each spot!! Now, I had color but these Cannas were making up my entire yard. I started digging them up, but only to see more coming up. Oh my, what to do?? I went to Dollar Tree and purchased 10 boxes of salt came home and salted every one of them. They wilted, turned brown, and were gone so I thought. To my amazement, they continued to come up. Finally, I got some 2, 4-D and sprayed every week for 4 weeks and no more cannas!!!!! Lesson learned.”
Some plants become invasive so one of the questions a gardener might ask is how much will a plant spread. If a plant likes to reproduce, then an area with hard boundaries may be a suitable site for it.

potato leaves with symptoms of several problems
potato leaves with symptoms of several problems

Potato plants

Many times gardeners believe there is a single cause of a plant’s health, but sometimes there are several factors affecting a plant. Jeff of Alexandria was concerned about his potato plants and sent in couple of images. Both images have fungal leaf spots due to the surplus rain occurring this spring. Fungicidal sprays will prevent the leaf spotting both vegetable on ornamental plants.

The image on top has purpling in the some leaves, and this symptom indicates low phosphorus levels. The on the bottom has yellowing, and this issues is due to low nitrogen levels. A soil test will precisely determine the amount of fertilizer a crop will need. Soil test kits are available at AgCenter offices and at some garden centers.

Millipedes, a harmless "bug"


Mr. Melvin sent via text message some pictures and his complaint, “[I sent] a few pictures of the bugs we are seeing here. These are in the garden under plant pots…”

These “bugs” are millipedes, and according to Rene Schmidt, a retired AgCenter agent, “Millipedes are beneficial to helping with decomposition of plant materials such as grass clippings, but they can be a nuisance when they move out of their burrows and into the home.

Because … millipedes are beneficial there is little reason to destroy them. But when they become an annoyance control may then be necessary. Granular products that contain bi-fenthrin, such as Talstar or Bug Blaster or any granular lawn insect product that contains pyrethrin will provide an effective control. Control would involve treating the outside perimeter of the home, at least 15 feet from the base of the house. Also treated should be the ground area adjacent to the foundation, edges of walkways, landscape beds and other areas which are heavily mulched and remain damp. Treatment inside the house is usually not practical.

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, please share the name of your parish.

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

6/3/2019 8:53:26 PM
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