Q I hope you can help me with a couple of gardening questions. I have six 17-inch hanging baskets that hang along our deck and are in full sun almost all day. I want to plant them with flowers to attract bees and butterflies. What would you suggest? In the past, I have filled my baskets and planters with a mix of one-third topsoil to two-thirds potting soil. Would you recommend something different?
A You have a lot of plant options, but I would recommend all potting soil, no garden soil, because of the weight. You could add in a small amount of the water-holding granules to aid in water retention, but remember, a little goes a long way. Some plants to try — the new Honeybells cuphea is fantastic in full sun and will cascade out of the pots. Hummingbirds and bees adore them. Other heat lovers for full sun include lantana, Pentas, scaevola, Bacopa and zinnia. They also have some new dwarf varieties of butterfly bush that would do well in a container and bloom all summer long.
Q I liked your article on pruning in the March 20 paper. I have always been puzzled by the instructions for pruning nandina. I understand cutting a third of the canes off at the ground. What if you want a shorter height overall?
A I like to have various heights on the stems to give a fuller plant. Keep in mind that all of the new growth will be from the top cut edge of each cane, if you are just pruning stalks. I would suggest taking a third of the canes back to the soil line and then cutting the others to whatever maximum height you want.
Q I love my nandinas but am ready to pull them up because I read the berries are poisonous to birds, particularly cedar waxwings. Your recent articles mentioning nandinas didn't address that aspect. Thoughts?
A This question comes up from time to time when the berry-poisoning article reappears. Nandinas have been in our gardens for more than 100 years, and you don't hear constant reports of birds dying from eating the berries, which would be the case if it happened with any regularity. The poisoning article stemmed from a case in Georgia in 2009 when someone found dead cedar waxwings in their yard. The dead birds were found stuffed full of nandina berries, and the cry went out. A variety of berries in our landscape plants contain trace amounts of cyanide. Certain weather conditions can concentrate the cyanide and a freak incident can occur — a similar event happened in Texas with deciduous hollies. Cedar waxwings can be gluttonous and don't know when to stop. Too much of a good thing can be bad, and that was the case in both incidents. Most gardeners want to cut off the nandina berries (on older varieties: newer cultivars are fruitless) because the berries can germinate and cause unwelcome spread of nandinas. In some parts of the state they have become invasive. So, manage your plants to keep them from spreading, but you should not have to remove them for the sake of bird health.
Q I have butterfly milkweed (Asclepias incarnata). Is that the correct seed for aiding the monarch butterfly? Is it the native milkweed I am looking for?
A There are many varieties of native milkweed in the genus Asclepias, and all are beneficial to the monarch butterfly. Asclepias incarnata is the swamp milkweed. Many gardeners plant A. tuberosa, the orange or yellow flowering form that grows on the roadsides in Arkansas. But choose plants that fit your site.
Retired after 38 years with the University of Arkansas Cooperative Extension Service, Janet Carson ranks among Arkansas' best known horticulture experts. Her blog is at arkansasonline.com/planitjanet. Write to her at P.O. Box 2221, Little Rock, AR 72203 or email jcarson@arkansasonline.com