QUESTION: How do I propagate the seeds from the yellow ohia? I love that plant! Mahalo. — Maile Yawata

ANSWER: Ohia lehua can be grown from cuttings, air layers or seeds.

Starting with seeds is the easiest and most fun way. You don’t need special propagation mist boxes or rooting hormones, just patience and daily gentle watering.

I had a lovely yellow lehua mamo that Misao Kimura, my secretary at Ho‘omaluhia Botanical Garden, gave me. I grew the plant faithfully in a pot, watering it every day. I knew it would not like the black cinder soil of my childhood home garden in Makiki. When we moved to Wahiawa, with its luscious deep brown soil, I dug a planting puka, adding compost and coarse cinder to improve drainage. I planted my precious lehua mamo in the ground and watered daily, unless we got a deep soaking rain.

It thrived, flowered and set seed. I planted some in my home garden and shared them with the Wahiawa and Ho‘omaluhia botanic gardens. I grew some in pots, as we prepared to move back to town.

The seedlings were mostly yellow-flowered, but some were red, and some orange. One of my faves was yellow with a hint of orange at the base of the flowers. I named this one “Misao’s Sunrise” in honor of that dear, akamai lady.

When we moved back to town it was to a very windy valley. It was February and the winds were so strong the house shook like a ship at sea. For a month! We didn’t have tradewinds like that in Wahiawa and nothing grew at first. It was too windy, and the soil was junk, pure clay.

Then one of my favorite local soil companies, Hawaiian Earth products, got this new tool for spreading high-quality soil and compost. It was called a “mulch shooter.” It’s like a concrete pumper, but designed to move soil.

We used it to spread a custom soil mix, one that we had used with great success at the Hale Koa Hotel; they even called our special blend the “Hale Koa mix.”

It was equal parts cinder, compost and clean soil, adding just a wee bit of manure. I would order this same mix for the gardens of my private clients.

I made a landscape plan and marked out where planter beds were going in our garden. Using the mulch shooter we laid down 30 cubic yards on top of the barren hard-packed clay soil. Then we brought our potted plants from Wahiawa and laid out the garden.

Neighbors still ask me my secret and what kind of fertilizer I use. Just “feed the soil” and your plants will grow well, I reply.

We planted ohia lehua from 6-inch or 1-gallon pots into the ground and watered daily. They grew really well. Recently I had to trim them away from the roof, and I saved the pretty branches to share as flower arrangements and in dry arrangements, too. There were few of the yellow flowers, but lots of seed pods.

As ohia are struggling with the dreaded rapid ohia death on Hawaii island, I knew it was imperative to save the seeds and grow more, and to share them with lovers of ohia lehua and to share seeds with Lyon Arboretum and the Ohia Legacy Initiative.

HOW TO SAVE SEEDS

>> Cut branches of ohia, place them in water, in a vase or a bucket.

>> When the seed pods start to turn brown and split open, cut the pods off the branches.

>> The seeds are tiny and look like golden eyelashes. Collect and save them in an envelope in a dry, cool place.

>> Plant them ASAP or share them with Lyon Arboretum or the Ohia Legacy Initiative.

HOW TO PLANT SEEDS

>> Fill a 6-inch pot with half potting mix, half course cinder.

>> Water it well, then press the mix down with another pot to firm it up. Let drain. Water again to deeply soak the mix.

>> Sprinkle seeds on top.

>> Cover with just a bit of mix. Gently water.

>> Gently water daily. I tell keiki gardeners, “water like the Manoa rainforest mist, not like a blast from a firefighter hose.”

The rule of thumb with seeds is to plant them only as deep as they are wide. Ohia seeds are so tiny they barely need covering, but cover them a bit.

You also want the seeds to be in intimate contact with the soil, thus the firming and double soaking.

In two weeks to a month you will see tiny green things, the keiki ohia lehua. When they have two sets of leaves you can transplant them to individual pots.

In a home garden (with no wild kids or rambunctious dogs) you can plant fairly smalls plants in the ground. In public gardens or in restoration habitats in the forest the plants should be larger to ensure survival.

Water the pots and the keiki trees daily. If planted in the ground they still need daily watering until they are at least 4 years old, or are well established.

Using mulch and leafy compost helps the trees retain water and spread their roots wide and fairly deep to grow and thrive.

Happy growing!

Heidi Bornhorst is a sustainable landscape consultant specializing in native, xeric and edible gardens. Reach her at heidibornhorst@gmail.com.