Temperatures remain warm, but things are about to change. September 22nd officially marks the start of fall in the Northern Hemisphere, as the sun then moves south of the equator. The autumn equinox is spring for those south of the equator. As the Earth tilts north, the sun appears to move farther away from us, days get shorter, and plants tend to slow their growth.
Even though we don’t see the brilliant fall colors in mainland forests and gardens in Hawaii, we can improvise. So now is the time to shop at nurseries and garden stores. You can find some great ideas to bring the fall feel to our gardens. Where the nights are cool and the days are frequently cloudy, try some of the fancy new impatiens hybrids. The New Guinea hybrids are especially attractive. These new hybrids are much more compact and bloom more profusely. They come in all flower colors and also have multicolored leaves. Other impatiens on the market are the traditional types that have been crossed to be compact and profuse.
Fall in Hawaii is colorful with African tulips, Timor showers, rainbow showers, and even the flame trees in late bloom. Various species of Bauhinia or orchid trees are also in bloom now. One species rarely seen here but common in cooler regions of South America is the silk floss tree or Ceiba speciosa. This close relative of the kapok tree is rare here but popular in Southern California. Some Hawaiian nurseries will ship it from California nurseries upon request. Your garden could be even more beautiful if you add croton, bougainvillea and hibiscus, to name a few.
In addition to the many tropical ornamental trees and shrubs that exist, you can also consider colorful annuals and perennials to brighten up your sunroom or porch. Many of the summer annuals that are most prized on the mainland bloom best here from November to May. These annuals typically tolerate cool weather. Because winter temperatures never get extremely low, they thrive here, especially at higher elevations like Kamuela and Volcano. Some, like the marigold, are great year-round. They do particularly well in sunny, drier locations.
The marigold is native to the southwestern United States and Mexico. It grows well and is popular in every state in our union, from Florida to Maine, from Hawaii to Alaska.
When Cortez conquered ancient Mexico, he found marigolds there. The magnificent golden marigolds were so beautiful that Cortez took seeds back to Spain. There, marigolds became the favorite flower of the faithful who placed them on the altar of the Virgin Mary, and so they were called Mary’s Gold and later known as marigolds. They were so easy to grow and so beautiful that they became popular everywhere. In India, marigolds are the favorite flower for flower garlands that are placed around the neck to show friendship, and so they have become known as friendship flowers.
Many different types of marigolds are available in your garden store, from large-flowered American marigolds to small-flowered, so-called “French” marigolds, with and without scent.
Marigolds, zinnias, petunias and many other annuals with bright flowers provide natural color. You can also increase the beauty and appeal of your flower borders by including low-maintenance foliage plants. Which ones are best for creating color and textural contrast?
Coleus springs to mind immediately and is probably the most popular. And no wonder, since they are so versatile and colorful! The plants, with their gorgeously patterned leaves, are eye-catching in sun or shade. You’ll especially appreciate how coleus can transform problematic shady spots into a rainbow of colors. Use them to brighten up areas along the north or east side of your home or garage, or in containers on shady porches or patios, even under trees. Coleus can also tolerate direct sun in cooler gardens. Coleus is popular as both a houseplant and a garden plant. They thrive in pots and are easily propagated by cuttings. Other popular plants include the many varieties of begonias, canna, caladium, and geraniums.
Other interesting deciduous annuals to consider include: Euphorbia leucocephala or “snow on the mountain.” This tree grows easily in dry soil and is a showstopper with its refreshing green and white leaves on plants about two feet tall. Holywort (Chamaecyparissus) or lavender cotton makes a lovely low hedge. The plants grow to about 45 cm high and have finely divided, aromatic, silvery-grey leaves and small, spherical yellow flowers. In the north it is kept as an annual plant, in Hawaii it is a perennial plant.
You can sow the seeds of such annual plants in boxes, pots or outdoors. If you use a container, make sure that it has good drainage. You can sow the seeds in vermiculite, peat moss, sand or mixtures of these. You can also buy already pre-grown plants from several garden stores and nurseries in the area. If you are pre-growing your plants yourself, water them when the seeds are in place, cover the containers with a piece of glass or plastic and place them in a sheltered place out of direct sunlight. In a few days, the seeds will germinate and more light will be needed to avoid leggy and poorly colored seedlings. When the first pair of true leaves develops, it is time to transplant. Place the tiny plants in pots or planting tapes. Later, plant them outdoors in their permanent location.
With your creativity you can beautify your house and garden from now until June.
