Native Water Garden

I rarely see a variety of Hawaii’s native plants being used for landscaping outside commercial buildings, so I was pleasantly surprised with the recently installed plantings outside Kawaiha’o Plaza, the administrative offices of Kamehameha Schools in downtown Honolulu. This multi-level raised planter seems to be designed as a miniature ahupua’a.

Mauka plants such as naupaka kahuahiwi, palapalai, and koa were planted at the top level...

Kalo was growing in a tiny lo'i at midheight along with native sedges...

Even 'ihi'ihi was there, an unusual endangered native fern that resembles a four-leaf clover. In the wild it grows in vernal pools, so naturally it's a good plant for the water garden...

At the very bottom were plantings of makai plants such as alula...

hala pepe and 'ae'ae...

As the landscaping matures it will be interesting to see how many of the plants will have to be removed or replaced, if any. The koa seemed planted too close to the building, and I was surprised to see the naupaka kuahiwi was still thriving even though it was at this low elevation. Nonetheless, I have much to learn from this landscaper -- I’m impressed! I’ll have to revisit in the future to check up on this very akamai and inspiring native water garden.

A Bittersweet Tale

Bittermelons look like what hedgehogs would be if they fell under a wizard's spell and became vegetables.

Once in a great while I like bittermelon Chinese-style with furu, fermented tofu. My Filipino neighbor loves bittermelon. Birds love his ripe bittermelon fruit and scatter the seeds, so occasionally I find vines growing in the middle of the lawn, which I mow anyway. However, now there's a bittermelon vine growing on the fence between me and my other Filipino neighbor. I'm sure neither of us planted it, but I'm not entirely sure if he's eating from it. He hasn't sprayed it, and usually he sprays the fenceline. It's actually my fence, so I guess I could just rip the vine out. But I don't want to spoil my neighbor's enjoyment, that is, in case he is in fact enjoying it. I suppose I could ask him, but he never answers the door when I go over.

So the vine just grows. Is it a weed? Some people would say if someone has found use for a plant, it isn't a weed. So I guess it isn't, because for me right now it serves as a reason to get to know my neighbor a bit better.

Half-Weed

Look! Is this Drymaria a half-dead or a half-alive weed?

Does limonene work as an herbicide? Two weeks after spraying I've decided the answer is yes...and no.

The label on the pesticide says that it is most effective on annual weeds shorter than 6 inches. I wanted to see what difference weed whacking would make before spraying, so I used a string trimmer to cut most of the weeds to ground level. I also left one patch uncut.

I found that the herbicide appeared to affect the foliage of some weeds that were whacked that weren’t affected when left intact. However, weed whacking before spraying didn’t seem to make any difference for hardier weeds. Limonene appeared to cause foliage to burn on some weeds but it didn’t outright kill them; the affected weeds put out new growth within 2 weeks.

For example, garden spurge greater than 6 inches that was sprayed looked healthy and unaffected, however buttonweed foliage burned though the stems seemed unharmed. Nutgrass sedge seemed to be unaffected by any of the treatments.



Limonene seemed to affect foliage of some weeds quickly. Oxalis turned yellow immediately upon spraying, as did Drymaria. I mowed sleeping grass (Mimosa pudica) in the lawn, then sprayed it; the weed and the grass surrounding it turned brown, but new growth appeared within 2 weeks.

Okay, so all of this is anecdotal and not so scientific, but you’ve read this far so you might as well read the rest of this half-baked report.

Unless someone convinces me otherwise, I’m not using limonene as a weed killer again. I’m sticking to my electric string trimmer and propane flamer for weeds that aren't kept in check with mulching and hand-pulling. Spraying limonene was a pleasant, fragrant exercise in weed abuse, but certainly not worth $21.99 as a weed control strategy. My conclusion: When life gives you lemons, don’t make weed killer.

De-lovely, De-weeds & D-limonene

A couple of weeks ago I happened to be wandering the “organic” aisle of my local hardware store, as I do every now and then to see what’s been added to the store’s inventory. In the past 6 years I’ve watched this section grow from one or two products to more than a dozen different ones filling half the length of the aisle, which I’d say is an indication of consumer demand. And on this most recent perusal I found something I’d never seen before: “organic” weed killer based on D-limonene, a citrus oil extracted from the rinds of oranges.

I’ve used other natural, earth-friendly limonene-based products: adhesive remover/solvent/degreaser, household cleaner, ant killer. Sounds like powerful stuff, doesn’t it? Since it’s OMRI-listed, of course it’ll be killing those weeds softly, shouldn’t it? However, if something says it’s “worryfree” I start getting skeptical. Is it safe, and does it work – really? I had to try it.

I usually pull weeds by hand or use a propane flamer to burn them. So a 32 oz bottle of concentrate for $21.99 nearly took my breath away – this is not cheap stuff, but then it wasn’t locked up like the Roundup was. On the way home I stopped to visit a friend. When I got back to my truck and opened the door, my sinuses were blasted with a familiar odor from small-kid time: Lemon Pledge. An oily scent, not entirely beckoning, like a crateful of Meyers with an industrial undertone. Apparently the bottle tipped, and even though the cashier had tightened it, it leaked into the plastic bag and a tiny bit spilled on the floor mat. Even a week later, each time my visiting niece got into my truck, she’d inhale deeply and sigh, “Mmm, auntie, your car smells so nice.” Not your typical reaction, but keep it out of reach of children anyway – read the label, there are some warnings.

The label says this weed killer takes care of “annual weeds” and that “perennial weeds may need more than one treatment.” I’m not sure what annual weeds are in Hawai'i though, since many plants perennialize here. When I bought the weed killer I did not know that even though it is a concentrate, 32 oz makes only 1 gallon of spray! I’ve decided that if this 70% D-limonene pesticide proves to be effective I’m going to use it only in areas next to the house where I don’t want to use flame.

Have a look at some of the weeds I’m trying it on.

(Warning: the following pictures may be disturbing to those with obsessive tendencies.)

garden spurge, koko kahiki, Chamaesyce hirta

Phyllanthus amarus

partridge pea; lauiki, Chamaecrista nictitans

bubble gum plant; root beer plant, Polygala paniculata

buttonweed (Spermacoce assurgens)

...plus oxalis and some assorted grasses and sedges.

Stay tuned for the results in the next couple of weeks!

Seeding Hawai'i's Future

If the 6th Annual Seed Exchange at Amy B.H. Greenwell Garden was any indication, Big Island gardeners are eager to grow all kinds of edibles, and that bodes well in the current push for sustainability in Hawai'i. Farmers, school gardens, community gardens and gardeners-at-large offered abundant seeds and cuttings to satisfy all appetites for homegrown vegetables and herbs, and they dispensed helpful advice for growing, too.

Nancy Redfeather and Jerry Konanui opened the event, welcoming festival-goers who brought gifts of fruit from their gardens to share with the community that had gathered that day.

After the presentation of the festival's theme of the creative power of fire, there were two exquisite hula performances. This introduction was barely over when the seeding frenzy began, however. The crowd was elbow-to-elbow, crammed into the tents; gardeners were buzzing about like honeybees, collecting their botanical treasures, filling baskets, bags, and envelopes with seeds and cuttings and talking story with fellow growers.

There were also excellent expert lectures, on topics such as seed saving and ways to create abundant gardens. Personally, I saw very little in the way of exchange per se; more frequent was the altruistic generosity of the festival participants who asked for nothing in return and freely gave propagation material to any member of the general public who wanted it. The true spirit of aloha came alive through spontaneous, thoughtful action. Each seed that was passed to a new gardener was planted in the sincere heart of someone seeking to grow more food for themselves and their community.

As it happens with many transforming experiences, sometimes pictures tell the best stories….

...beans, Hawaiian poppy, tulsi brahma (purple)...

...locally grown cacao seed...


...seeds for medicinals: olena (tumeric), organic tobacco grown in Honaunau; okra seed...

...tropical 'sun hemp,' a nitrogen-fixing, green manure cover crop...


...jackfruit tasting: savoring the 'ono flesh, then saving the seed...


...Know Your Farmers Alliance was there, of course...


...and perhaps even you were there. If not, hope to see you next year!

Code Red for Green Thumbs

Are you gardening by the codes? Most likely you are, but in case you aren’t, it’s time to get educated.

The Voluntary Codes of Conduct are recommended by the Center for Plant Conservation for those participating in various aspects of horticulture. These guidelines are designed to promote education about invasive species and to encourage affiliated groups to take appropriate action in preventing the spread of invasive species. One of the key purposes behind the codes is to make groups self-regulating so that there will be less need for government regulation when problems from invasive species become severe.

This week I proposed that the Hawai’i Island Master Gardeners Association adopt the Voluntary Codes of Conduct for the Gardening Public, and I’m happy to report that they voted for it. This puts them at forefront among organizations that are working to educate the people of Hawai’i about their kuleana – their responsibility – to preserve our native ecosystems and watersheds.


The Center developed several professional Voluntary Codes of Conduct. There are codes of conduct geared for five specific groups: Government, Nursery Professionals, Landscape Architects, Botanic Gardens and Arboreta, and the Gardening Public. So far over 45 major groups across the nation have endorsed these codes, including influential nurserymen and landscape architect associations, botanic gardens and garden clubs. The University of Hawai'i Lyon Arboretum in Honolulu is the first botanic garden in Hawai'i to adopt the codes. See a list of all the groups here.

I hope that you, too, will make a personal commitment to adopt the Voluntary Codes of Conduct for the Gardening Public, and tell others about them, too. Unlike the continent, Hawai’i is a small, isolated place; change, good or bad, affects us in a big way. The choices you make even in the gentle pastime of gardening can have a major impact in the quality of life that surrounds you.

Voluntary Codes of Conduct for Gardening Public

• Ask for only non-invasive species when you acquire plants. Plant only environmentally safe species in your gardens. Work towards and promote new landscape design that is friendly to regional ecosystems.
• Seek information on which species are invasive in your area. Sources could include botanical gardens, horticulturists, conservationists, and government agencies. Remove invasive species from your land and replace them with non-invasive species suited to your site and needs.
• Do not trade plants with other gardeners if you know they are species with invasive characteristics.
• Request that botanical gardens and nurseries promote, display and sell only non-invasive species.
• Help educate your community and other gardeners in your area through personal contact, and in such settings as garden clubs and other civic groups.
• Ask garden writers and other media to emphasize the problem of invasive species and provide information. Request that garden writers promote only non-invasive species.
• Invite speakers knowledgeable on the invasive species issue to speak to garden clubs, master gardeners, schools and other community groups.
• Seek the best information on control of invasive plant species and organize neighborhood work groups to remove invasive plant species under the guidance of knowledgeable professionals.
• Volunteer at botanical gardens and natural areas to assist ongoing efforts to diminish the threat of invasive plants.
• Participate in early warning systems by reporting invasive species you observe in your area. Determine which group or agency should be responsible for reports emanating from your area. If no 800 number exists for such reporting, request that one be established, citing the need for a clearinghouse with an 800 number and website links to information about invasive plant species.
• Assist garden clubs to create policies regarding the use of invasive species not only in horticulture, but in activities such as flower shows. Urge florists and others to eliminate the use of invasive plant material.

Feel the Need for Seed

Seed savers unite! Trade your local-grown seeds and cuttings of food plants and get together with other beneficently seedy types this weekend at the 6th Annual Hawai'i Island Seed Exchange at Amy B.H. Greenwell Garden in Captain Cook, Saturday, June 21, 8:30 am to 12:30 am . This event is sponsored by Amy B.H. Greenwell Ethnobotanical Garden, Hawai'i SEED, and Know Your Farmer Alliance.

You'll have an opportunity to network with like-minded gardeners and learn more about what's happening in your growing community, maybe even get a glimpse at the wonder and excitement sprouting up in school gardens across the Big Island. This event promises to be fun and educational for all ages!

I'll be there in a special book signing tent with other invited agricultural authors, including Craig Elevitch and Dr. Scot Nelson. Stop by and say howzit!

Determined to Know Beans

Beans are wonderful, magical, rewarding. They’re vigorous and with proper cultivation they’re fairly trouble-free, even in a container. Children especially like growing them because when they sprout the plants look sturdy and robust and it’s easy to see and describe the various parts such as the cotyledons, stem and so on. Last week my jaded 13-year-old son was still delighted to plant some Black-Seeded Blue Lake snap pole beans, certified organic from Seeds of Change, and this week they’re up. I grow them in a wine barrel with a bamboo trellis, and last year I could barely keep up with the harvest. Fresh from the garden, the taste is so…beany. I see older, tougher beans in the supermarkets more often these days than tender young beans which are delicious, so growing your own is a good idea.

I start with organic potting mix – I usually use something OMRI-approved, such as Black Gold. In large quantities that can be too costly, so sometimes I make my own mix using various media. There are several good potting mix recipes online from ATTRA that you can access here.

I add compost and some organic fertilizer, such as Bio-Flora dry crumbles, or whatever I have on hand. The key to preparing the media for beans is to not add too much nitrogen, or you’ll end up with very nice green leaves and very few beans. Insects will usually leave your plants alone if you keep them healthy.

A word about watering. Beans are susceptible to rust and bacterial diseases, so do not wet the leaves or you might spread disease throughout your plants. However, beans do need adequate water, so don’t let the potting mix or soil completely dry out. Water them as needed; morning is best, that way plants have a chance to dry out during the day. It’s a good idea to rotate your crops to reduce the chances of establishing pathogens.



I prefer to grow pole beans because they tend to produce more. There are a few varieties that were developed especially for our growing conditions by the University of Hawaii. (These aren't GMO, by the way.) Manoa Wonder is root-knot nematode resistant, which is a plus if you’re growing them in the ground. Hawaiian Wonder is rust resistant, and Poamoho is stringless. Usually you can find these seeds in garden supply stores, sometimes even in grocery stores. But if you can’t, you can order them from the UH website here.

When your beans start producing, keep harvesting them regularly so that you’ll get a steady supply all season long for stir-fry, seasoned with dill or garlic. If can, can! Most people don’t have time to do canning nowadays, so give your surplus away. Remember, with the rising cost of food your local food bank will appreciate the donation of fresh produce from your garden this summer.