Several years back, the Breadfruit Institute, part of the National Tropical Botanical Garden on Kauai, received a grant to give away some 10,000 ulu trees around the state. The intention was to expand Hawaii’s breadfruit production as a means to building food security.

Indeed, few crops are better suited for such a role, since this nutrient-rich, cultural food thrives in our tropical climate.

Some of those trees now may be close to bearing fruit. But how many still exist, where are they rooted, and how much actual fruit are we talking about?

To find out, Noa Lincoln, an assistant professor at the University of Hawaii’s College of Tropical Agriculture and Human Resources, and UH graduate student Blaire Langston are heading up a three-year study that asks the public to become “citizen scientists.”

The Ulu Phenology Project is seeking people who can commit to observing an ulu tree for about a year. The tree can be in their own backyard or in another place that they have access to, such as a school or church, Lincoln said.

Participants will record information about their tree every couple of weeks: whether it has flowers or fruit, and if so, an estimate of how much. Data can be submitted on a project website or called in.

Phenology is the study of plant life-cycle events such as fruit and flowering, and how these are influenced by the seasons, climate and habitat. This is especially relevant in the case of ulu because, as Lincoln said, it is “notoriously sensitive to climate.”

In general, ulu has two fruiting seasons — one from late summer to fall, about July to September, and January to February. In some places, though, trees have a third season, around May, he said. Variables such as sun exposure, rain, cloud cover, humidity and temperature affect seasonality.

Based on the data collected, phenology maps for various regions can be created to help support the growth of an ulu industry.

Ulu trees usually fruit in their third to fourth year, and potential yield is incredible: Production from single trees is often cited to be 300 pounds per year, although numbers of up to 2,000 pounds from a single tree have been recorded. Trees are productive for decades. The challenge is ulu’s seasonality and short shelf life. A million-dollar question, then, is whether plantings can be manipulated to provide a year-round supply.

“We’re trying to find that out,” Lincoln said of the study.

Langston said the study has some 60 active participants, most on Oahu.

Her work entails not just the study itself, but another goal of the project: increasing public awareness and education. Langston shows up at agriculture-related, Earth Day and food events to discuss everything from ulu research to ulu handling, and shares recipes as well.

It pays off. One of her participants is actually a whole troop of Boy Scouts based in Waianae. They’re observing a tree growing at the Waianae Coast Comprehensive Health Center.

And sometimes, participation brings out a bit of the tree hugger in citizen scientists.

“Some people in our study say they really enjoy forming a closer relationship with their tree,” said Lincoln. “It takes just five minutes every two weeks, and it’s made them much more in touch with their tree and the natural cycles of our weather. We can tend to take those things for granted.

“It’s a cool process.”

VEGAN ULU SALAD

• 1 large mature (not ripe) ulu, cubed
• 1/4 cup red onion, diced
• 1 small red bell pepper, diced
• 1/2 bunch parsley, chopped
• 1 clove garlic, minced
• 1-1/2 cups Vegenaise
• 1/4 cup mustard
• Salt and pepper, to taste
• Paprika (optional)

In pot, boil ulu until tender, then drain.

In bowl, combine ulu, onion, bell pepper, parsley and garlic, then stir in Veganaise, mustard, salt and pepper. Taste and adjust seasonings. Sprinkle with paprika if using. Serves 4.

Approximate nutritional information, per serving (not including salt to taste): 780 calories, 55 g total fat, 9 g saturated fat, no cholesterol, 700 mg sodium, 68 g carbohydrate, 12 g fiber, 25 g sugar, 3 g protein.