Gardening in the Santa Cruz Mountains’ microclimates can be challenging, and it’s no different here in Maui, where I am vacationing.
Yes, despite the balmy weather, the rainfall here limits which plants thrive. You can drive five minutes from an area that receives 400 inches of rainfall per year to another spot 10 minutes away that gets only 19 inches each year. Then, drive another 15 minutes and you’re in a desert-like area with annual rainfall of 10 inches, even as the east side of the island, in Hana, gets 83 inches.
Gardeners in Maui solve these challenges in several ways.
One way is to grow the right plant in the right place. For example, at 4,000 feet of elevation near the volcano, 55,000 lavender plants of 45 varieties grow happily in rocky soil.
Olive trees — shipped over from Santa Cruz — dot the fields. It’s interesting to note that the lavender plants provide a natural pesticide against the ants that invade the protea flowers.
Proteas do well here. It reminded me not to miss our spectacular show of proteas at the University of California, Santa Cruz Arboretum in April and May. If you’ve never walked through that free garden, it’s a treat not to be missed.
If you think all the soil in Hawaii is of volcanic origin, think again. Of the 12 types of soil in the world, seven different orders occur here. The state of Hawaii, as a whole, has 11 types, more than any other state in the United States.
By comparison, Maine has only four types, while the Santa Cruz Mountains has a whopping nine orders just in our little corner of the world. Yes, folks, that’s right. No wonder gardening can be a challenge where we live. What thrives up the road from you doesn’t always grow the same way in your yard. Knowledge of soil behavior and nutrients is important wherever you garden.
Maui has a native pea, a native coffeeberry and a native huckleberry, just as we do. There is even a native hydrangea, although the type we are most familiar with was brought over from Japan in 1790. Mostly, visitors to Maui see flowering plants introduced from other parts of the world.
Since the 1800s, people have been transporting all types of plants to Hawaii, just as early settlers did in our area. Many of the plants that we commonly grow, like the Princess flower (tibouchina) and strawberry guava, are invasive in the islands. Others, like blue plumbago, bloom in the drier areas and behave themselves. Gardeners here face the same problems as we do and strive not to dilute the native gene pool.
The rain in Maui is distributed throughout the year, which is different from our Mediterranean climate. Before you get jealous, though, note that this allows slugs, whitefly and fungus to proliferate year-round. I see mealy bugs under most of the plumeria leaves.
Incidentally, this intoxicatingly fragrant tree is easy to propagate and grows everywhere on the islands. If you get at least six hours of hot sun per day and keep the plants inside or in a greenhouse above 50 degrees on cool nights, plumeria will bloom even in our area.
I’ve enjoyed my time in Maui, but there’s no place like home.
• Jan Nelson, a California certified nursery professional at Plant Works in Ben Lomond, will answer questions about gardening in the Santa Cruz Mountains. E-mail her at ja******@ao*.com.
