Volcanic Acid Rain

Unusually hot, dry weather and increased voggy air quality is making me the only slug in my garden these days.

Watery eyes, stuffy sinuses, and an overall feeling that one should lie down like Dorothy in a field of poppies outside Oz are just some of the symptoms many Hawai'i Island residents are experiencing with the natural volcanic air pollution from the new lava flow in Kalapana. The publicly accessible flow going through Royal Gardens and down to the ocean is putting on a spectacular show for residents and tourists alike, and it’s also filling the skies with two to four times more SO2 (sulfur dioxide), a component of acid rain. Although we haven’t had substantial rain in Hilo for the past week or more (proof that it doesn’t always rain in Hilo!), when the rain returns in earnest we may have to bear of the effects of volcanic acid rain on our plants, too.

Clean air is vital to growing healthy plants, and vog and acid rain has been the cause of many frustrating crop failures on the Big Island. Foliage and delicate flowers get burnt by SO2 emissions, and entire nurseries can be wiped out. What can be done about it? A Kurtistown nursery owner told me she tries to shut the vog out of her greenhouse using curtains. Sometimes it works, but sometimes the vog is so bad it just permeates through anyway and she loses stock. "I try to trim the burnt parts off, but then everything looks like stems and sticks and I have to just dump them," she said, shrugging it off with a laugh, dealing with it like a true kama'aina.

Indeed, it’s all just Pele doing her thing, and again we’re reminded of the whims and power of nature. Unfortunately, what's a bummer for the backyard gardener is economic ruin for some farmers and the further weakening of our already fragile agriculture industry on Hawai’i Island.

Some native Hawaiian plants are adapted to survive in vog and acid rain conditions. On the trail to the lava viewing point there were pioneer plants such as the tough kupukupu fern, for example. These natives are perfect for landscaping in lava hazard zones especially in the district of Puna, where a lot of new landscaping has been going in. The population in Puna has increased dramatically in the past five years, predominately with an influx of newcomers from the continental U.S. Much to their surprise, what works in gardens back in North America doesn’t make a flourishing Eden here.

Too often landowners bulldoze from pin to pin, taking down native ‘ohi’a lehua, uluhe and hapu’u ferns. When their lots of lava are scrubbed clean of vegetation, they quickly discover that if they don’t plant something soon they’ll be inundated with weeds. So they ask the UH extension service what kind of plants are easy to grow in pahoehoe lava. Hmm…how about ‘ohi’a lehua, uluhe and hapu’u ferns, the things that you just bulldozed and that had been growing for the past 30 years or more?

If you’ve just moved there, Malama O Puna is more than happy to give you advice on the best native plants to grow and what plants to avoid in your area. Call them at 808-965-2000, or contact them through their website here.