Global warming has made forecasting weather a big gamble. Generally speaking, Hawaii’s rainy season is usually November through April. The exception is Kona that has a summer rainy season with a dry winter. Other variables include elevation and the effect of moisture-bearing tradewinds. Thus mauka areas of the windward side may receive 200 or more inches of rain while coastal South Kohala may receive very little rain throughout the year. On the leeward side, coastal Kona may receive 30 inches of rain in the summer, but at 2,000 to 4,000 feet elevation, summer rainfall may be 60 to 100 inches. Kona Cloud Forest Sanctuary at 3,000 feet in Kaloko Mauka has recorded no dry season for almost three years while the windward side has experienced unusually dry weather.
Wherever you live, the first plants to show water stress are those with shallow roots like grass and many groundcovers. These are good indicators as to when you need to irrigate. They are also likely to tell you when to fertilize if you are sensitive to your plants’ needs. You should apply plant nutrients when the soil is moist during rainy periods or when you can supplement water with irrigation.
Whether you have a home with a large yard or an apartment with a small lanai, plants create a more luxurious mood. Attractive trees, shrubs and lawns actually increase the value of a home. In fact, if you cut down that big shade tree in the front yard, you may actually be reducing the value of your property by thousands of dollars. Just think how much it would cost to have a landscape company replace it! When trees are destroyed, it affects the whole community.
The key to success is to put the right plants in the right place. Hot sunny areas of the islands require shady gardens to create a comfortable environment. Windbreaks are important to reduce excessive winds. Many tropical landscapes do not include grass. Examples may be found in books like “Tropical Asia Style,” “Thai Garden Style,” and several books featuring the Hawaiian landscape. The use of palms adds even more luxuriance to the design.
Besides trees, shrubs and bedding plants, one of the main elements of many landscapes is ground covers including grass. It might be Bermuda, buffalo, centipede, zoysia, seashore paspalum, or a mix. Whatever type lawn it is, green and healthy is the key. It is important to remember that lawns generally require more maintenance, fertilizer and water than more deeply rooted ground covers, shrubs and trees. Thus, many communities are minimizing turf except in parks and recreational areas like golf courses.
However, it is pleasing to see a healthy, well-maintained lawn. An expanse of green lawn can serve as the right setting for the homes they surround.
From a practical standpoint in the tropics, a lawn serves a number of ends. First, it reduces heat and glare as the sun beats down on the earth. Green is a soothing color. No doubt that is why there is so much of it in nature. Second, it controls mud and erosion. It definitely beats concrete and asphalt or gravel.
The chief value of a lawn over other kinds of ground covers is that it offers a pleasing place to walk and play, as well as being artistic. In a dry area, a grass such as Bermuda makes a successful path, or can be used for auto parking.
A well maintained grass cover also offers one of the easiest ways to control weeds. Just mow frequently and fertilize occasionally, making sure the grass cover has sufficient water to keep its green color.
Of course, if you want a perfect lawn that is a different proposition. Your idea may be just a green expanse to set off the surrounding landscape. Then it really does not matter of what the expanse consists. It may be a combination of grasses kept in check by frequent mowing.
Lawns are a garden heritage from Europe. They are not typical in Asia except through Western influence. Asian design uses moss, pebbles or sand for its plain element in landscaping. But in England, turf is key to the landscape and has become an essential part of the garden tradition. Mainland Americans have inherited this tradition. They generally consider a lawn a necessary part of the landscape. However, in the wet tropics, turf is generally not a part of the native picture, since meadows are infrequent. Here, it is a good idea to stop and consider whether or not a lawn is an essential part of your garden. In many parts of the mainland where water may be scarce and expensive, grass is fast disappearing as an aesthetic element.
Shady forest effects with paths and patios tend to relate to the tropics more than do extensive lawns. And yet even here, there is much use of the lawn in open expanses around a dwelling.
A perfect lawn in the tropics can be an expensive proposition. To keep it perfect requires constant attention to weeding, rolling, fertilizing, mowing, watering, and control of diseases. Just about the time you think you have everything under control, some new condition arises, and the lawn goes up in smoke.
Today there is a strong inclination to let the lawn be more informal along with the rest of the garden. Such a mixed green cover has its appeal, being more like a meadow than the monoculture lawn. A semi-natural lawn like this has its practical aspect also. It reduces maintenance by eliminating most of the weeding and also the struggle to make one kind of grass grow under the varying conditions of sun and shade which make up the average lawn area.
There is, no doubt, a legitimate reason for cultivating a green expanse around a dwelling even in the tropics. But let’s not make such a burden out of it. When a weed pops up here and there, let it be. The secret is not in exterminating the weeds, but in keeping the area mowed so that the weeds cannot dominate and go to seed, keeping them from spreading too much.
Whatever type lawn you have, chances are it will require watering except the extremely rainy locations. Deep watering is preferred. Frequent shallow watering will encourage shallow rooting. It is best to water in the early morning. There is less waste of water through evaporation at that time.
Along with water, green growing things need fertilizer. This is especially true with the lawns. A fast growing grass like Bermuda may need fertilizer every month. On the other hand, Zoysia may be fertilized three to four times per year or less. A slow release fertilizer high in nitrogen is usually the best.
The important thing is to think green. We humans have created too much desert in the past. The old saying, “Rain follows the forest, desert follows man” does not need to apply to wise Hawaiian gardeners.