It seems like our dry weather in West Hawaii may be trending toward a normal summer rainy season. Folks in East Hawaii laugh when we complain about drought since they have been getting plenty of rain. But some spots in Hawaii have experienced the driest weather in many years. Kona has seldom been this dry in a century, according to some oldtimers, and this follows a serious drought in 2010. Even wetland forests are beginning to suffer. Since October, the Kona Cloud Forest Sanctuary in Kaloko Mauka has seen only 4 inches of rain.
On the mainland, the weather east of the Rockies was so warm that it broke all kinds of records. Who knows what the future will bring, but such is the life of a farmer or gardener.
With spring almost over and summer officially starting June 21, folks are getting the gardening bug again. Garden magazines and garden supply stores are now featuring bulb advertisements and displays. Gladiolus, cannas, gloxinas, tuberous begonias, callas, amaryllis, clivia and caladiums are just a few of the many types available.
Although they vary in their requirements, there are several basic cultural factors to keep in mind. In general, most bulbs grow best in a well-drained soil and a sunny location. The pH of the soil should run between 5.8 and 6.5. Most bulbs should be fertilized with a low nitrate analysis fertilizer according to manufacturer’s directions on the label. If you keep these factors in mind, you should be able to produce excellent bulbous plants.
Energetic gardeners can have some bulbous crop in flower every month of the year. However, let’s concentrate on some spring flowering bulbs we can plant now.
Calla lilies can be started now and will flower during summer months. Incidentally, calla lilies are an exception to the cultural suggestions we have already mentioned. Callas will perform best in a soil that has considerable organic matter and is retentive of moisture, but not soggy! In order to obtain the best results, the clumps should be dug every three to four years and the rhizomes separated and replanted at a depth of 4 inches. Callas are at their best in cooler sections of the island like Volcano and Waimea, but they will grow in warmer sections as well.
One of the most popular bulbs to try is the amaryllis. Amaryllis bulbs can be planted any time during the winter and early spring months. Depending on the variety or hybrid grown, they will flower from through May. The amaryllis is like most folks after the holidays — it must watch its diet. Too much food, and the plant will not bloom, so it fluorishes in poor soils like we tend to have in West Hawaii.
Here are a few tips to get your amaryllis to do their best. First of all, don’t tempt them with rich foods. Nitrogen-packed fertilizer makes the plant fat and green with few blooms. Like many other bulb plants, amaryllis bloom best when fed a miserly amount of a low nitrogen fertilizer. The idea is to starve the plant into worrying about next year’s blossom so that it will store food into a nice big bulb for the future blossoms, plus giving you a proud display of blooms this year. If the plants grow rampant on little or no food, try planting them in less fertile soil next time. Rationing water during the late growing stages will tend to produce better bulbs.
Bulbs planted now will put on a flower show in six to eight weeks. Select a fairly sunny spot for an amaryllis bed, because too much shade will cause small flowers. Deep shade may cause the bulb to die.
Colors to choose from are red, pink, white and a combination of these colors.
If you can afford them, buy hybrid bulbs. With reasonable care they will give you bigger and better blooms.
With fancy varieties, when the tops of the amaryllis die back in the fall, it is time to dig and store the bulbs. Upon digging, remove the smaller offset bulbs from the “mother” bulb. It will take about three years for the juvenile bulbils to bloom, but in the meantime, the mother bulb will show her colors plus produce additional infants for future generations of flowers.
Propagating bulbs by cuttings is an interesting hobby. To try your luck, use a razor sharp knife and cut a “mother-size” bulb into a number of pieces — up to 60 pieces if you have the knack of thin slicing. Be sure that each wedge of the bulb has a portion of the stem tissue attached to the scale portion. Next, dust the wedges with a garden fungicide to prevent diseases and plant them in a flat or bed containing a mixture of peat and sand or other porous medium. Keep the planting moist and humid, and in about four weeks small bulbils will appear between the scales. The tiny bulbs are ready for potting. Three years later, you’ll have a mother bulb that will bloom.
To propagate amaryllis by seed, harvest the seed pods soon after they turn yellow and begin to break open.
Dry the seed pods a few days before sprinkling the seeds onto a flat. Start the plants off in full shade, but gradually move them into full sunlight, then transplant them to a sunny spot in the garden.
Canna lilies are great warm season bloomers. They are in the banana family and are not true bulb plants, nor are they lilies. Other popular warm season bloomers include the many varieties of day lilies. Some local nurseries even specialize in the many hybrids. There are many other bulbs that can be planted, such as clivia, agapanthus and spider lilies, or crinums.
For fragrance and for leis, try the popular tuberose. Of course, some bulbs like narcissus should be planted only during cooler months. You can also grow tulips here. Just store the bulbs at 40 degrees Fahrenheit for 60 days prior to planting and be sure to plant them immediately after removal from cold storage. Since tulips require cold weather, they have to be replaced every year or grown at elevations of 6,000 or more feet. For more information about the culture of bulbs, ask your local garden shop, or nursery. Several gardening books are also available at local bookstores on the subject.
This information is supplied by the University of Hawaii College of Tropical Agriculture and Human Resources. For further information, contact the office near you.