“Groundwork” column for Sept. 20, 2013

When do I prune blackberry plants? How about Star or Confederate jasmine? And how can I get ride of pesky bamboo? The LSU AgCenter expert has these answers to your questions.

When should blackberry plants be pruned?

Prune immediately after harvest. One method is to cut all canes 6-12 inches from the ground. The other method is to selectively prune all the bearing canes (the ones that produced fruit) and leave the new, tall growing canes. Tip prune the tall growing canes at 30 inches tall to encourage branching.

I noticed the shucks on my pecan tree have a lot of black moldy spots on them. Is this going to damage the pecan itself? I do not recall having this problem before.

Pecan scab disease is likely infecting the pecans. This disease affects pecans throughout the growing region and is one reason for breeding new varieties. Practically speaking, it is impossible for homeowners to treat large pecan trees. Expect losses to vary annually.

I am new to the area (a transplant from Michigan) and wondering if there are any classes I could take to learn about gardening in Baton Rouge.

Please email me using the address below and I will send you information on the Master Gardener’s Basic Gardening Series at the East Baton Rouge Parish Jones Creek Regional Branch Library starting Thursday, Sept. 26, and continuing Thursdays, Oct. 3 and 10.

I have a section of Star or Confederate jasmine that I’d like to hard prune, but don’t know if I should do that in late winter before new growth in the spring or after spring bloom. When is the best time?

Either time would be culturally correct, but I recommend waiting until after flowering in May to prune so you can enjoy the flowers and fragrance. The vine will have adequate time to regrow and mature its growth before winter.

Some years back, my husband planted one or two bamboo plants to hide a device in our yard. Now the bamboo has spread wildly, taking over other parts of the yard. How can we get rid of it?

If you are able and willing to kill everything, then Arsenal is the best herbicide to use. If the bamboo is growing with desirable plants, then cut the bamboo to the ground, allow it to begin regrowing, and then apply a herbicide with 41 percent glyphosate at the rate of 6.5 ounces per gallon.

Got a gardening question? Write to Bob Souvestre, horticulturist with the LSU AgCenter, at Burden Center, 4560 Essen Lane, Baton Rouge, LA 70809, or email to bsouvestre@agcenter.lsu.edu, or call Master Gardeners at (225) 763-3990.