What's the best grass for a shady Oahu yard?
For shade on Oahu, Zoysia is usually the most forgiving common choice — it tolerates lower light better than Bermuda, which really wants full sun and thins out fast in shade. Seashore Paspalum is great for salt and irregular water but also prefers sun. That said, deep shade (under dense trees or on the north side of a two-story house) will challenge any turf — at some point a shade-tolerant ground cover, mulch, or a small hardscape area is a better, lower-effort answer than fighting to keep grass alive. Matching the grass to your specific light and soil is worth a quick look from a pro before you sod.
Answered by ProScape Hawaii · Lawn care
I found a big black beetle near my palm — should I be worried?
Possibly — if it's about two inches long, glossy black, with a single horn on its head, that's the coconut rhinoceros beetle (CRB), an invasive pest that bores into and can kill Oahu palms. Check your fronds for V-shaped notches and the crown for bore holes. Either way, report it to the state pest hotline at 643-PEST (643-7378) or 643pest.org — even one beetle, even if you've killed it, because reports help track and slow the spread. Then keep mulch and green-waste piles finely ground and turned, since that's where the grubs breed. For a damaged or tall palm, have a licensed arborist take a look.
Answered by ProScape Hawaii · Pests
How often should I water my lawn on Oahu?
It depends a lot on where you are. Windward lawns (Kailua, Kāneʻohe) often need little or no supplemental water in the rainy months, while leeward lawns (Ewa, Kapolei) may need deep watering 2–3 times a week in dry stretches. The rule that matters more than frequency: water deeply and less often, early in the morning, so roots grow down and the blades dry before evening (wet overnight grass invites fungus here). A smart controller with a rain sensor pays for itself fast by skipping cycles when the trade showers do the job for you.
Answered by Aloha Sprinkler & Outdoor Design · Irrigation
Do I really need a backflow preventer for my sprinkler system on Oahu?
If your system ties into the Board of Water Supply (BWS) potable water line, yes — a backflow assembly is required by code, and it protects your drinking water from being siphoned back through the irrigation system. It's the part handymen most often skip. New installations can trigger a required backflow test, and the assembly should be kept in working order. If you're not sure whether yours is compliant, a licensed irrigation pro can check it and handle the BWS paperwork.
Answered by Aloha Sprinkler & Outdoor Design · Irrigation
My water bill jumped but my yard looks fine — could it be my sprinklers?
Very likely. Because Oahu systems run year-round, a slow underground leak on a lateral line or a valve that isn't fully closing can waste water for months with nothing visible at the surface. Walk the yard a day after the system runs and look for a spot that stays soft or wet — that's usually the culprit. Also check for heads that mist or spray sideways (high pressure wastes a surprising amount). If nothing's obvious, a pressure test will pinpoint a hidden leak quickly.
Answered by Aloha Sprinkler & Outdoor Design · Irrigation
