Fall officially begins this coming week as the sun moves south of the equator. We feel the effects as days grow shorter and temperatures start to cool. Most of the island has received more than enough rain as well so it is a good time to think about adding some new garden plant specimens.
If you need some help selecting just the right plant for your home or garden, here are some tips to add lushness and color to those shady spots.
Those spots in the garden, such as under a big tree, make growing difficult, but here is a chance to do something especially luxuriant with landscaping. The same holds true for a shaded lanai or in the home. Impatiens are great for cooler areas of the island where rain or irrigation is sufficient. Their preference for shady areas helps, too.
You can add sparkle to dull areas with the wide range of brilliant colors available. And they are versatile as well. You can plant them in tubs, window boxes, hanging baskets, or spot them in groups in shady borders. You do not have to pinch the newer impatiens varieties to make the plants bushy. They branch naturally at the base and cover themselves with an abundance of flowers. They really light up the shade, especially when contrasted with the rich green of ferns.
Check with our local nurseries and farm and garden centers for these new improved types. Ferns make good groundcovers for shady, moist locations. If under trees, they profit from the decayed leaves that fall, since a high organic soil is to their liking.
Not all ferns, of course, will serve this purpose. But there are really more than one can imagine. Many ferns spread easily and rapidly from the runners that grow from the original plant. One of the principal groups of ferns used for groundcovers is the genus Nephrolepis. These are the ferns commonly called sword ferns or Boston ferns. The name Boston now applies to several beautiful ferns, all mutations of the wild sword fern, Nephrolepis exaltata.
Horticulturists have developed bushy plants from the original, some with rugged leaves like the parent, others with graceful lacy leaves such as whitmanii, elegantissina, and smithii. These lacy ferns are used more as pot specimens than for outdoor planting. The most commonly seen in the garden are Nephrolepis exalta and Nephrolepis biserrata. In fact, they have naturalized in moist forest areas or Hawaii. They fill in well, and if the location is naturally moist, they need little care or attention.
Nephrolepis duffii has small, roundish leaves. It does not grow tall like Nephrolepis biserrata, so would serve well where a low planting is wanted. Another that can be used in this manner is the Polypodium polycarpum, commonly known as the elk’s horn because of the crested formation at the top of the fronds. They will grow to about 2 feet. The holly ferns, cyrtomiums, are a good choice for groundcover use. They may get as tall as 2 feet if conditions are to their liking. They are called holly ferns because the individual leaflets are shaped like large holly leaves. They are tough and leathery. They do best in loose, organic soil, with sufficient moisture.
Plants will stand some sun during cooler weather, but only a little in the summer. The Pteris genus includes many species can be used as a groundcover or for hanging baskets. Don’t forget our many native ferns. You will find some in garden shops and some you can carefully transplant from the wild with permission from the landowner.
Many ferns are pioneer species and may be found growing in disturbed soil along the roadside or recently cleared fields. The exception is with our native hapuu, or treeferns. They are very slow growing and should not be removed from private or public lands without permission. Others we should mention are not true ferns, but are to be considered for a shady ground cover. These are called fern allies, and are very beautiful. The genus is Selaginella. Some varieties have a peacock feather sheen that is quite attractive and unusual.
Care of ferns is easy in our humid climate. Soil should be high in organic matter. Fertilize occasionally and lightly with an organic liquid or granular material high in nitrogen. When using manures, be sure not to burn ferns. Sufficient water is important. Pests generally are not bothersome when plants are grown in the garden. Do not spray ferns unless absolutely necessary. Avoid chemical sprays commonly used on other plants, since these pesticides may burn the foliage. With most ferns good drainage is a must since plants should be kept moist, though never soggy.