As today marks the first day of summer, the longer day lengthens the time that plants transpire, or lose water through stomata.

Your urban horticulturist recommends watering your garden plants slowly and deeply in the morning hours to keep plants hydrated. Morning watering is not only the optimum time for plants to drink, but also will conserve precious water resources.

Did you know that only 1 percent of the water found on Earth is drinkable? Next time you cut into a papaya fruit, try this demonstration for keiki:

Cut the papaya in four equal parts. One part represents Earth's land, the other three represent all of the planet's water. Set the "land" aside.

Explain that most of the planet's water is salt water found in our beautiful oceans. Then slice off 1/8 of one of the three papaya parts. This small piece represents fresh water.

Next, cut the small piece into three equal parts. Two of these pieces represent frozen water, unavailable for us to use. The remaining one represents the fresh water that we need to live. Conserving water is important because without it, living things could not survive.

At the Pearl City Urban Garden Center, O'ahu master gardeners are practicing water-wise gardening. Soaker hoses — widely available at local garden centers — are positioned around newly planted native vines in the ecosystem garden. The efficient hoses have allowed gardeners to cut back on watering per week. Also, spacing the hoses 3 inches to 4 inches from the base of the plants encourages new root systems to grow toward the drip line. Three inches of mulch covering the soaker hose — and additional mulch around the base of the plants — help prevent water from evaporating. The newly planted vines are vigorously growing and now receive water only once a week.

Planting a native plant, laying soaker hoses that drip water and adding a thick layer of mulch are the key ingredients to our "green" garden successes. Water-wise practices are not only for the garden. Once a glass of water sits by your bedside table until morning, do you pour the water down the sink? Try adding that water to a house plant or a plant in your garden.

Ask keiki for ideas on saving water. They may surprise you. Call O'ahu's master gardeners at 453-6055, 9 a.m. to noon Mondays to Fridays, to add your suggestions to our water-wise gardening ideas.

Jayme Grzebik is O'ahu's urban horticulturist and master gardener coordinator at the Pearl City Urban Garden Center with the UH Cooperative Extension Service. For moreinformation, e-mail Grzebik at Grzebik@hawaii.edu.