Larry asks: It seems like we are entering a dry season. Any suggestions for gardeners when we have less rain?
Tropical Gardener answer: Despite the occasional storm that blows through, we typically do have less rain in the winter here in Kona. Several suggestions might help you and your garden as we experience drier days ahead.
If you are putting in new plants be sure to choose ones that are drought tolerant. Many natives are able to tolerate long dry seasons. Check out a presentation on drought tolerant natives at https://www.ctahr.hawaii.edu/rnre/Native_Plants_Water_Conservation.asp to get some ideas.
Beyond the drought tolerant natives, many other plants can tolerate less water. Gardens that require little water are often referred to a xeriscape gardens. Two books written by Hawaiian plant experts Rauch and Weissich are available and can be very helpful with plant selection. “Watersmart Gardening,” and “Plants for the Tropical Xeriscape” are both worth checking out at the library or a local bookstore.
Cacti and succulents are excellent selections for a drought tolerant landscape. Even several fragrant tropical plants are somewhat drought tolerant including plumeria and spider lily. Bird of paradise, agave, aloe, bromeliads and ti plants as well as trees like moringa, neem and orchid tree are also tolerant of our dry season.
Some herbs and vegetables as well as a few fruit trees can withstand dry spells rather well. Lavender, rosemary, thyme, oregano, sage and chamomile are good candidates for a drought tolerant herb garden. Most beans and peppers do fine with little water as do squashes, corn and okra. Dry farming tomatoes is a standard practice in areas with long dry periods. They’ll need water to get going, but once they start flowering, you can cut way back on water to them. Citrus trees well as pomegranates will also be fine with less water.
If you are putting in new plants that are not drought tolerant during dry season, put them in pots. They’ll need less water and you can install them in our garden once the rains return in the summer.
You can help your plants that are not drought tolerant adjust to fewer rainy days by watering them deeply and less often. By only watering once or twice a week, their roots will likely grow deeper to take advantage of moisture held deep in the soil.
If you have an irrigation system in place, set it to water longer and less often. Of course, drip irrigation is a good way to maximize water use during dry season. It is most efficient to set your timer or establish your watering schedule to water early in the morning. Potted plants are best watered in the late afternoon, however. When hand watering, be sure to water the soil rather than the plant for best use of limited water.
Mulching can help your plants tolerate dry spells well. Organic mulching material placed a few inches thick in the root zone (but a few inches away from the trunk of the plant) will help hold moisture and discourage thirsty weeks. This will also break down into healthy soil. If you are using wood chips, be sure to sprinkle them with a little nitrogen to help them break down without robbing the soil of nitrogen. It is wise to avoid any heavy fertilizing, however, during dry season. The new growth produced by fertilizer adds to a plant’s water needs.
You and your plants will likely enjoy the cooler weather ahead and by following some of these tips, your garden should flourish despite less rain.
For more ideas for xeriscape gardening go to http://www.ctahr.hawaii.edu/uhmg/news/V4-Xeriscaping.pdf.
Email plant questions to firstname.lastname@example.org for answers by Certified Master Gardeners. Some questions will be chosen for inclusion in this column.
Diana Duff is a plant adviser, educator and consultant living part time in Kailua-Kona.