The vast majority of introduced plants stay in the gardens where they are planted. Without their native pollinators or preferred climate, their survival and spread depends on humans. Our careful maintenance keeps them going. Take breadfruit and citrus trees — they flower and fruit in Hawaii, but can’t set seed and therefore don’t spread in the wild. If you want these plants, you have to cultivate them.

A small subset of introduced plants spread without human help. “Of the roughly 12,000 to 13,000 non-native plants present in Hawaii, only about 12 percent have become naturalized, or have formed self-sustaining populations in the wild,” explains Chuck Chimera, the Weed Risk Assessment specialist with the University of Hawaii.

Naturalized, non-native species are those we regularly see hiking or driving down the road.

They are the plants in the unmanaged parts of the land, spreading without our help, forming self-sustaining populations that will persist year after year. Sometimes we take notice of them, like a mountain apple along the roadside. Sometimes we overlook them, like self-heal, a small, purple flowered plant in the mint family — it grows from the lowlands to around 8,000 feet, given enough water.

Plumeria, from Mexico, is a harmless addition to a garden. These plants, like most introduced plants, remain in cultivation and cannot spread without help. FOREST and KIM STARR photo

Introduced plants or animals often provide a service to us or to the environment: Cook pines collect water from passing clouds, sweet potato and citrus fill our bellies, wild hives of European honeybees pollinate our gardens, and red-billed leothrix spread the seeds of native plants.

It is only tiny subset, roughly 1 percent of all the introduced species, that spread aggressively and outcompete native Hawaiian plants. Capable of transforming our ecosystems, these are the invasive species that land managers battle. Miconia, fountain grass, little fire ants and strawberry guava are among the most notorious. While these bad actors get a lot of attention, most foreign introductions are benign, and even provide benefits to us.

Take time to appreciate the beauty and savor the tastes of all the introduced species that abound. A Valentine’s bouquet of locally grown flowers, a meal of fresh fish on a bed of locally grown greens, haupia for dessert. Support your neighborhood farmer or flower grower at a farmers market or grocer. Doing so helps prevent the accidental interisland spread of hitchhiking pests like little fire ants or coqui frogs.

Please make wise planting decisions; check before you plant. The Weed Risk Assesment is 95 percent accurate at predicting the likelihood of a plant becoming invasive in Hawaii. Check it out at plantpono.org.

* Lissa Fox Strohecker is the public relations and education specialist for the Maui Invasive Species Committee. She holds a biological sciences degree from Montana State University. “Kia’i Moku,” “Guarding the Island,” is prepared by the Maui Invasive Species Committee to provide information on protecting the island from invasive plants and animals that can threaten the island’s environment, economy and quality of life.