If you want to get a sense of what life was like during the Carboniferous period some 300 million years ago, visit the Kona Cloud Forest above Kailua-Kona.
The area abounds with ferns that once were dominant millions of years ago. You can take a walk along Kaloko Drive or opt for a guided walk Saturday, Oct. 3, by contacting Janet Britt at 769-4343 or Alex Kelepolo at 315-3757 of Moku 0 Keawe. The tour will start about 10 a.m., and since space is limited, be sure to call soon.
Since we are still in the midst of our infamous pandemic, wear your face mask, comfortable shoes and clothes. Remember, it is is 80 degrees in town, it will be 65 degrees at the Kona Cloud Forest Sanctuary, where the tour will be conducted.
Ferns, in general, are free of insect and disease problems. They require very little fertilizer but do require moisture and shade from intense sunlight. Our cooler mauka areas and east side of the island are probably the best for growing ferns, but many types can be grown almost anywhere with protection.
We have hundreds of ferns, native and introduced, in Hawaii, but this is just a fraction of the more than 9,000 species found throughout the world. Members of the fern family vary from moss-like mini ferns to gigantic palm-like tree ferns more than 40 feet in height.
A side benefit of ferns is that some are edible. Fern shoots add an exotic touch to vegetable and pork dishes, along with bamboo shoots. Many edible ferns such as the Arythrium esculentum of Southeast Asia are also high in Vitamin A.
In the landscape, ferns give that ultra tropical look that really makes a garden special. The most striking effect, by far, is created by the tree fern types.
In Hawaii, our native Cibotiums are being used in the landscape but are slow growing and becoming scarce. The hapuu ii, or male fern, usually dies after transplanting. The so-called female fern can be transplanted before new leaves emerge in the spring, but often dies when planted out of its natural wet habitat.
To establish them, plant in a rich organic soil and keep them moist and shaded. Within a couple of weeks, they will begin developing large, airy leaves and roots. A shady spot protected from wind is best. They should be watered on the trunk and at the base frequently.
Live stumps can sometimes be purchased locally. Do not remove ferns from the forests. It is illegal without permission. They are becoming rare in some areas because of cutting and removing.
Some other species of tree ferns are carried by a few local nurseries. These include types from Central America and the Caribbean, Southeast Asia and Australia. They are well adapted here and fairly fast growers. Under good conditions, they will produce fronds higher than your head in a year or so. With room, they will form a trunk to 10 feet or more. These species are more tolerant of sun and dry conditions than our native hapuu.
When planting ferns, be sure to enrich the planting sight by adding peat moss or rotted compost and some well-rotted manure to the existing soil. A good ratio is about 50% peat, 40% cinder and 10% well-rotted manure. New plants should be watered daily until they are established.
Ferns are sensitive to chemical fertilizers, so use them sparingly. It is better to use organics such as sewage sludges or rotted manures. Fertilize about once every 2-3 months for best growth. Avoid liquid insecticides and fungicides because they, too, will burn. Diluted wettable powders are safer.
Ferns are extremely susceptible to herbicides, so be careful.