Our bamboo is dying back at a faster rate than usual. The dieback begins at the new growth and works down. The bamboo is growing in part shade, the soil drains fairly well, and there have been no chemical applications. However, magnesium chloride was used last winter to remove snow on a path, and it was piled on the bamboo for a few weeks. Could magnesium chloride cause the dieback?
It's very likely you are seeing salt damage from the magnesium chloride. This de-icer can cause "moderate" plant harm (which is still better than other de-icers; see our Fact sheet 707 Melting Ice Safely). Injury symptoms include poor or stunted growth in the spring, dieback on evergreen plants, and marginal leaf browning or leaf scorch. Most salt problems can be treated by soaking the affected area with an inch of water, three to four times in the spring. This year's rainfall should have already done this for you. You may want to test your soil's salt levels this fall. (We provide a list of soil test labs online or by phone.) If salt levels are high, your next step is to add gypsum to the soil to absorb the high sodium.
Another possible cause for the dieback would be an infestation of powder post beetles. These long dark beetles are common pests of bamboo. They chew holes in culms, leaving little piles of sawdust. The control is to cut down and remove infested culms.
Is there such a thing as a Master Gardener course?
The Master Gardener program is operated by Maryland Cooperative Extension, the outreach education arm of the University of Maryland. This popular program includes training courses, plus opportunities for continuing education and community service. Contact your county or city Extension office to see if they offer the program in your county or in a nearby county. Slots fill up fast. For more information, visit www.mastergardener.umd.edu.
1. Be a good neighbor and protect the Bay by picking up and disposing of pet waste when you walk your dog.
2. Prevent fungus gnat problems around houseplants by allowing the top of the potting soil to dry out between watering.
3. If you have bulbs that didn't get planted, try forcing them indoors in containers filled with a soil-less growing medium (a mixture of peat, perlite and vermiculite). Or keep bulbs in a cool, dry location wrapped in ventilated plastic bags and plant as soon as the garden soil can be lightly worked.
Jon Traunfeld, regional specialist, and Ellen Nibali, horticulture consultant, work at the University of Maryland Cooperative Extension's Home and Garden Information Center. The center offers Maryland residents free gardening information and answers to plant and pest questions. Call its hot line at 800-342-2507 (Monday through Friday, 8 a.m.-1 p.m.) or e-mail questions to www.hgic.umd.edu. (You can also download or order publications and diagnose plant problems online.)