Calvin R. Finch, Ph.D., Conservation Manager, San Antonio Water System, and Horticulturist
Week of March 4, 2002
Q. My potatoes have not emerged from the ground yet even though I planted them four weeks ago. Are they dead? Should I replant?
A. It has been so dry for the last four weeks that I would not expect your potatoes to rot unless they have been over watered. Dig up one or two pieces to see what has happened. If they have rotted, replant and reduce watering. My guess is that it has been so cool at night that they are just slow.
Q. Fire ants have invaded my birdhouses. They climb the fence post and are making themselves at home in the box. What can I do?
A. Clean out the box and spray the fence post with orthene, malathion, or sevin. If you can find the ground nest treat it with a fire ant treatment. During the breeding season it will help to protect the nesting birds if you spray the base and lower parts of the post with one of the insecticides.
Q. What are some groundcovers for shade? I am giving up trying to grow grass under my oaks.
A. English ivy works in areas where deer are not a problem. Asiatic jasmine is the favorite groundcover for shade. Monkey grass is pleasing for small areas. Shrimp plant, Turks cap, and Texas Gold columbine are my favorites.
Q. What is the difference between agapanthus, amaryllis, and crinum lilies?
A. The amaryllidacae are confusing to many gardeners, including me. Paul Cox, the Assistant Superintendent at the San Antonio Botanical Gardens, offered the way he tells them apart. The family includes amaryllis (Hippeastrum), spider lilies, crinum, daylilies, and agapanthus. They are not in the lily family despite the mention of lily in many names.
Crinum has strap-like foliage from which a flower stalk emerges with tubular 4- to 6-inch white, pink, or bicolor blooms. They are generally free blooming and have fragrant flowers. They are hardy permanent plants in our area. The bulbs have a long neck and the leaves are pointy.
Agapanthus have strap-like foliage as well, but the flowers are blue or white. Most of the agapanthus we use in this region have relatively small blooms 2- to 3-inches that are borne on large clusters over the plant. They bloom from summer to fall.
Amaryllis (Hippeastrum) has strap-like foliage but usually only two leaves. The leave ends are rounded. Flowers can be many colors but the best and hardiest plant for South Texas is the St. Josephs lily or Johnson hybrid, which is orange-red with a white stripe in the bloom. The amaryllis bloom in spring and has a spicy fragrance. The amaryllis that people give and receive for holiday plants are modern hybrids that do not survive well in our gardens.
All of the Amaryllidacae grow best in well-drained soil in morning sun but can tolerate poor soils. Crinum is especially tolerant of poorly drained areas.