Thursday, September 06, 2007
When to plant spider lily bulbs?
Landscape consultant John Arbogast answers your questions every Thursday. Send questions about your lawn, garden, plants, or insects to:
5102 Greenfield St. SW
Roanoke, Va. 24018
Or send an e-mail. Answers will be given only in this column. Please don't send pictures or samples.
- Are white pines the favored evergreen?
- Pepper problems
- Mature trees: when to cut them down
- Take a chance on eucalyptus
Q: I've become interested in spider lilies. Should I plant the bulbs now, in late summer, or should I wait until the spring?
A: First: How cold are the winters where you live? My answers will be based on a location in USDA hardiness zone 7, which is where Roanoke is located. Sites north of here or higher in the mountains than Roanoke should treat spider lilies as annuals that must be planted each spring. If you plant them in the spring, dig them up and store them indoors at the end of summer.
The common name "spider lily" is used for two different, unrelated bulbous plants. One of them blooms in the spring here in the upper South. It needs to live in the type of boggy environment found in low-lying woodlands, swamps, moist fields and the damp areas along the edges of water gardens. I refer to this as the true spider lily, because its large, fragrant white flowers each have six long, thin petals radiating out from a funnel-shaped center. The petals resemble the long legs of a spider attached to a smaller, round body.
The botanical genus name of this spider lily is Hymenocallis. The bulb survives winter chills in hardiness zones 6 through 10. (Hardiness zone numbers increase as they dip south.) In these zones, you should plant spider lily bulbs outdoors in mid fall.
The other plant also called "red spider lily" carries the name because its bright red September flowers gives it a spidery look. The flowers appear quickly after the plant's stalks emerge from the ground. The botanical genus and species name of this red spider lily is Lycoris radiata. It is typically found in hardiness zones 7 through 10. You can try planting the bulbs of red spider lilies in these hardiness zones two to four weeks after your first fall frost. I can’t find any information on growing these lilies as an annual.
Q: Why can’t I grow vegetables that make fruits or seeds in my sloped, mostly sunny, 20-feet-by-20-feet Roanoke garden spot? I have had disappointing production from what I remember gardeners many years ago calling “the vine vegetables.” I haven't had any luck growing zucchini, yellow crookneck summer squash, pumpkins or numerous varieties of cucumbers (and some of the cucumbers that did grow were small and misshapen). I’ve had poor luck trying to grow garden peas in the spring. Beans have not been prolific. My sweet corn this year has produced pretty well, but all the ears have been small. I have added organic matter to the garden soil and have taken soil tests over the years. We have woods adjacent toand downhill from this garden spot, but I don’t believe that any tree branches hang over the garden. Would you recommend giving up on this particular garden spot?
A: Let me pick up on some clues. The misshapen cucumbers and low production from your "vine crops" is probably the result of inadequate pollination. These are all vegetables that depend on bees to pollinate their flowers.
The small size of your corn and low production of beans and spring peas are likely caused by inadequate sunshine. The plants are telling you that less sunshine is hitting the site than you think. I would guess that there are other things blocking direct sun from reaching the garden: a house, for instance, or a shed that stands in the way as the summer sun moves in its arch from sunup to sundown.
Insufficient airflow can also be a problem in gardens that are located close to an adjacent barrier: a house, a shed, or, in your case, the woods. This can cause slow seed germination and can disrupt the survival of young garden seedlings because the soil temperature is cool in the spring.
Before you give up on the many years you’ve spent on soil improvement try another year or two of growing only leafy green vegetables and those we grow for their root harvests. These two categories of vegetables don’t require full-day direct sun or abundant pollinators.
Most leafy green and root-producing vegetables are grown as spring and/or fall gardens, since they may bolt to seed or, in the case of radishes, become bitter or strong-tasting in hot weather. Irish potatoes are the notable exception to this generality, since they need a long season from planting in the spring to producing and harvesting in the late summer and fall.
Of course, if your family doesn’t like greens, beets or radishes, the suggestion to give up on summer fruiting vegetables is no good. If you’re like me and use gardening as your horticulture therapy, contact your local food bank to see if they might need spring and fall produce. If that fails, you might have to give up on this garden spot.