Q I can't seem to get calla lilies to bloom for more than one year. I dug and stored the bulbs over winter. The second year they put out plenty of foliage but no flowers. How can I get them to bloom again?
A Calla lilies are native to South Africa. They will survive outdoors over winter only in the warmest parts of the United States (zones 8 to 10). In colder areas calla lilies can be planted outdoors after frost, then must be dug up and brought indoors over winter. They also can be grown in containers, which are then brought indoors.
The most likely reason for lack of bloom after the first year is that the foliage just didn't get enough time in the sun. Through photosynthesis, the foliage creates "food energy" that is then stored in the bulblike rhizomes. Good flower development depends on having a good energy supply. In our short growing seasons, there's a limited amount of time that the calla lily's foliage can do its job.
If you have a cool, sunny room, you may want to try growing calla lilies in containers, then treat them like houseplants over winter. They require evenly moist, almost wet, soil, plus high humidity and cool temperatures. They also need bright light even in winter, which is tough to provide at our latitude. Supplemental lights are helpful.
Q I'd like to grow some edible flowers to add to salads. Which flowers are best for this?
A Edible flowers are a colorful and attractive addition to salads and other dishes. It's very important to realize that not all flowers are edible; some, in fact, are quite toxic. Be sure you know the correct identity of flowers before eating them.
One of the best edible flowers is nasturtium. Nasturtiums serve double duty because their flowers as well as their leaves are edible. They provide a peppery, watercress-like flavor, which is a nice accent in mixed salads. Nasturtiums are easy to grow in full sun and well-drained soil. They come in a range of warm colors including yellow, gold, orange and red.
Other edible annual flowers include the dwarf single marigold cultivars "Lemon Gem" and "Tangerine Gem," calendulas, pansies and violas (commonly known as Johnny-Jump-Ups). The flowers of daylilies and squash (including zucchini and pumpkins) are used in several ethnic cuisines.
Many herbs also have edible flowers. The flower heads of chives can be broken into individual florets and added to salad for a mild oniony accent. Borage has beautiful blue flowers that have a mild cucumber flavor. The flowers of anise hyssop, basil, rosemary and dill are all edible.
Remember to try small samples of edible flowers first. People with allergies, especially pollen allergies, may have adverse reactions to eating flowers. It's also important to make sure that the flowers have not been sprayed with pesticides that are not labeled for food plant use.
Nancy Rose is a horticulturist, writer and photographer. To ask her a gardening question, call 612-673-9073 and leave a message. She will answer questions in this column only.