Helpful ideas for weed eradication and creative ways to reuse erosion debris

By Heidi Bornhorst

I asked my friend and great Gardener, Mari who lives Mauka of Sunset beach how bad the shoreline erosion was, and can she access her beach?

NO, she said sadly, It’s still blocked off and there is a steep Cliff, and dangerous drop off, it is too dangerous to walk down to Sunset Beach or Kammieland.  

Plus, she continues, there’s so much beach litter and trash everywhere that are a result of “temporary” sandbag burritos and black saran shade cloth.

Along with the liter there are multiple safety issues including rebar, concrete and other structural debris from coastal houses. These houses are now too close to our North shore surf swells, breaking waves and high tides.

BUT, says Mari, there is one upside to this trash and mis-use of our public beach.

My friends and I gather up the black matting erosion control debris that is floating in the ocean. (And yes, its very heavy when waterlogged).

What do you do with it then? We dry it out and SOLARIZE a most hated weed.  You know that Asparagus pokey groundcover? Or sometimes called Asparagus Fern?

Asparagus “fern” is not a fern,  Asparagus sprengeri is actually in the Lily family and is related ot our edible asparagus. It is very pokey, and if it pokes your bare gloveless hands, it’s kind of toxic.

I used to favor it for landscaping because it is extremely tough, xeric, and a good ground cover in a dry neglected garden.

But as a maintenance gardener I HATE it! Its pokey and the pokes from the minute thorns on the stems, can get infected. (remember to put on your garden gloves!) It has underground storage tubers, like little potatoes that make it a drought tolerant survivor plant and also Supremely difficult to eradicate.

You can dig and dig it out, but if one small tuber is left behind, Auwe!  It will all sprout up again.

And it has RED FRUIT, with several black seeds inside.  Birds love to find and eat red fruit and then they poop out the seeds everywhere.


We were talking about the wave erosion, high tides and overly heated water, and global warming change to north shore  and illegals things people are doing..

How’s about the guy pouring concrete and rebar on the beach?  Didn’t someone see it and report the Concrete Company?! Really unfortunate and unsafe issues here. Something needs to be done to save our beaches and Kai for everyone. Hard to watch.

Though there are many things we cannot control, the reuse of this beach trash to help eliminate a weedy plant in the garden, this is AKAMAI!

SOLARAZATION is a great way to control weeds without using dangerous chemical herbicides.

Often we use layers of wet newspaper, cardboard or even carpet to smother and solarize weeds, and turf grass where we don’t want it etc. Then after the weeds are safely killed, you can peel them away, restore the soil, and plant useful plants in place of alien weeds.

The black saran or shade cloth which some use as weed controlling ground cover, or in this case to slow down the power of wave erosion, can be used to solarize and kill weeds in our gardens.

This a beach clean up with a purpose!

Mahalo to Mari and her North shore friends who help clean our beaches and then grow good productive gardens.


Arbor Day 2022, Brachychiton acerifolium, Illawarra Flame Trees

By Heid Bornhorst

After three years of lockdown, we are finally, Happily, able to celebrate Arbor Day in Kapi`olani Park once again.

On Saturday November 19, 2022, we will gather with ScenicHawaii, Inc., Kapi`olani Park Preservation society, some Dedicated City tree workers and Arborists, Volunteers, and all of us who love and cherish trees and our Park.

We will be planting and ceremonially mulching four new trees courtesy of the Division of UrbanForestry led by Certified Arborist Brandon Au and DUF/ City and County of Honolulu Parks Department.

Citizen Forester Emily Perry will be representing our busy parks director Laura Thielen.

The trees are drought tolerant and are native to coastal subtropical forests of Australia.

The common name is FLAME Tree, or Illawarra Flame tree. Also called the lacebark tree.

One thing our mentor Paul Weissich, Director Emeritus of the Honolulu BotanicalGardens taught us, is to look beyond flowers when you view trees.

What does the bark look like? How is the truck shaped? What is the growth pattern? What kind of shade pattern does it adorn the ground with? What are the leaves like? Are they good for mulch and soil nurturing? For Keiki art projects?

As we Arborists say, “Touch trees”. Place your hand on the trunk and look UP! What do you see, in the Tree Canopy? I love doing this with keiki of all ages!

When we plant a tree, we are investing in, and finding out about the future. This small tree, grown from a tiny seed and planted today. What will it grow into in the Future?

We can read about the size and growth habits in a book, but how big will it really get here in Hawaii? Will it grow big and strong with proper nurturing and akami tree maintenance?

Will it withstand the abuse that trees sometimes take in public park spaces? Will most people be happy and respect the growing young trees? We sure hope so! Trees ensure a healthy, happy future for all of us.

Known in Scientific Latin as Brachychitonacerifolium, the Illawarra Flame trees are in the Sterculiaceae plant family.

We don’t have many of these trees in Hawaii.  A few grow at Foster and Ho’omaluhia Botanical gardens. These were grown from seed by the Horticulturist and Plant propagators at Foster Botanical Garden.

They are particularly striking when in bloom,with bright red orange or scarlet flowers. The flowers look like a hanging red bell when viewed from the side. If you look directly at them, they look like stars.

The leaves are shaped like a kukui leaf, or a mainland maple tree leaf.  This is what the species name acerifolium means.  Acer is the Latin name for Maple, and folium as you might guess is referring to the foliage or leaves, maple shaped leaves.

The trees will grow up and into a pyramid shapewith a tall, greenish grey, smooth round shapedtrunk. In time they can grow up to about 100feet tall (30 – 35 meters). They are a popular street tree in Australia and around the subtropical world.

The seeds of Brachychiton species are edible. But like many plants in the sterculia family they have irritating hairs, which must be removed or carefully removed to get to the edible seeds. Native Australians ate them raw or roasted. They are nutritious, containing 18% protein and 25% fat with high levels of zinc and magnesium.

There are uses for this tree in its native Australia. Fiber is made from the bark and a kind of gum can be extracted. The wood is soft but dries hard. Shingles, among other things, are made from the wood. The roots of young trees are edible, but let’s not do this in our park!

A related tree, Brachychiton rupestris is called the bottle tree.  It grows a big fat water retaining trunk over time, somewhat like the Baobab tree from Africa.

Mahalo to Wikipedia for some of this info, I also referred to our old standard book: In Gardens of Hawaii, by Marie C. Neal.

Pandan Wangi

By Heidi Bornhorst

Pandanus amaryllifolius
Working at the Honolulu Zoo, we were helping move and relocate plants for the community gardens from behind the zoo on Paki, to a new garden on Leahi and Paki.  As we were helping the (unhappy) gardeners, I heard Victorino Acorda, one of our best Gardeners and true plantsman exclaim in delight!
‘Pandan wangi!  Makes the rice taste so good Heidi!  I’ve been looking for this plant since I moved here from the PI!’
He was almost crying; he was so happy!
Then the other day I was stuck in morning traffic on Mo`oheau St in Kapahulu.  To amuse myself I looked closely at gardens along the street.  There was a really nice garden with a southeast Asia flavor.  First, I noticed nice clumps of lemon grass and some healthy papaya trees.
What was the clumping bright green plant in front of the lemon grass?  PANDAN WANGI!

So attractive in this landscape design and so useful.
We have it growing in the southeast Asian plant section at Ho’omaluhia Botanic Garden.  One year it was a featured plant at our plant sale, and we hope to feature it again once we can open up our gardens safely once again.
It is fairly easy to grow.  You can divide the clump and make new plants.  

Those who know this plant usually just call it pandan. There are many ways you can cook with it.
Some call Pandan, the Vanilla of the east, or the vanilla of Southeast Asia.
You can boil with whole leaves and combine them with other ingredients.  You can wrap foods in them and then cook them (like we do with Ti leaves).
If you’re handy with your blender, grind some fresh leaves with water and then freeze the juice in a mold or ice cube tray and use it for drinking or cooking later.
You could also add it to GREEN SMOOTHIES
Some just buy a bottle of pandan paste.  Lexi had some from Singapore, she had it quite a while I smelled it and then read the label.  It smelled really ono. The ingredients not so much.
How do we make it from the fresh leaves that we can grow in our Gardens?
You can just chop it up and add to the rice pot as you cook your rice.
You can make tea with the leaves. You can add your favorite tea like jasmine to the pot.  Pour hot water over both and let steep for Five minutes.
I made some with just hot water, poured over and steeped over leaves. it tasted ok
On 9 28 21 trying strip leaves lengthwise in 3s, add Olena and ginger powders, and three mamaki leaves, bring to a boil, then simmer for 30 minutes or so. It Smells really good!
There are lots of Creative and Foodie things you can do with pandan:
• Twist the leaves into Roses like we do with Ti leaves
• Little cups for deserts
• You can make green smoothies with it
• Pandan Chicken and Pandan Rice
• Grilled Fish stuffed with Pandan are just a few recipes that are popular.
And many desserts, variously featuring coconut milk, and various sugars like palm sugar.
If you look online there are lots of recipes, some quite layered and complex.  Some really pretty drinks and you insert a leaf tip to give it that final Flare of Gourmet Drink décor.
It gives the dish a lovely green color and subtle flavor.
I took some in mixed arrangement as a hostess gift for Lexi Hada and Barney Robinson.  One of their guests, Teua from the Cook Islands admired it, drew it out of the arrangement and sniffed it.
As he ran his hands over the glossy thornless leaves, we talked about it.  He recognized it as a Pandanus, or HALA relative but NO THORNS! We all wondered how it would be for weaving.
The Latin name, Pandanus amaryllifolius refers to this. The growth is much like a hala, but the leaves are soft and shiny with no thorns.
Besides being ONO, it’s a very attractive garden accent or spotlight plant in your garden.
I also like it as an exciting and exotic foliage element in a Tropical Flower arrangement.
We plan to feature it at a Future Covid 19 safe FOHBG plant sale.

Helpful Tips for Beautiful Landscapes

In my experience, people visiting Hawaii are truly interested in our unique plants and wonderful Hawaii gardens. Visitors vote and share with their cameras, with the questions they ask and the notes they take. Did you know that gardens and trees do not depreciate? They just keep on growing. The same cannot be said for buildings, sewers, sidewalks, pools and all the other accoutrements that make up Hawaii’s hotels.

At the Hale Koa Hotel, I researched and planted many new things in its 72 acres of gardens for the enjoyment and benefit of visitors, especially those who returned every year (or twice a year). Gardeners can be valuable customer service representatives and serve as front-line ambassadors. A nice gardener who can answer guests’ questions is more likely to bring new business and happier repeat customers.

Some people may or may not believe we have seasons in Hawaii, but professional Hawaii landscapers know we do.

For me, learning how to properly care for all the amazing plants here in Hawaii is a continual process, so I thought I would share with you some helpful landscape tips.

Tips and suggestions for a beautiful and professional Hawaii landscape

1. Create a highly visual and unique visitor experience by using native Hawaiian plants and well-adapted beautiful exotics in hotel gardens, interiorscapes, and landscapes.
2. Plant plants where they belong (salty soil, dry or wet area, shady or sunny).
3. Plant in layers — low, medium, high.
4. Plant shrubs + ground-covers around trees like a “lei,” to protect the trunk and highlight the tree.
5. Group plants that require the same conditions.
6. Understand how big a plant will become and how quickly it will grow.
7. Create and retain shade trees and shady walkways.
8. Understand how hard or easy a plant is to prune.
9. Use ground-covers as much as possible. They save on water, weeding, mowing and edging.
10. Hire a professional from the start and do the job right the first time.

Caring for landscapes using good Hawaii based horticultural and Arboriculture science principles and akamai maintenance practices will save money and beautify Hawaii. That is a great thing for all of us and our visitors

Heidi Leianuenue Bornhorst is a landscaping consultant, gardener trainer, and specialty VIP garden guide. She has been a professional horticulturist for more than 33 years. She is also a Certified Arborist. You can contact her via email at or at 739-5594.

Espalier your Mango!

With land so valuable in Hawaii, homes and gardens are getting smaller, yet we still want to grow fruit trees, but how can we?

Even with towering monster houses and high-rises blocking sunlight and air circulation, espalier is one solution which can help your garden to be more fruitful.

What does espalier mean and how is it done, you may wonder.

Espalier is a technique that is ancient yet artful.  We think it started with the Romans, and was enhanced by Europeans with Castle courtyards. The French enhanced and grew the technique to they could have fruit year round.

The word is French, with Italian origins. Spalla means something to rest the shoulder against in Italian.

Modern landscape design does look to the French and Italians.  Some of the first beautifully designed, landscaped gardens were in Italy, check them out on your next Continental journey. (Gardens are way more fun to visit than a museum, in my opinion, and you get better outdoor exercise too)

Espalier means”to train a fruit or flowering tree to grow flat against a wall, supported by a lattice, or a framework of stakes”.

Today we can use strong cables to train and attach mango or other fruiting tree branches to keep them low, to get maximum sun and air circulation, and for easy harvesting.  Or we can do something more artful and horticultural in our Hawaiian gardens.

The European reasons to do this apply here too:

  • Walls reflect sunlight
  • Walls retain heat overnight (trees use the heat and then cool the air)
  • Orient the leafy branches to absorb maximum light
  • Train the branches parallel to the equator to get max sunlight
  • Espalier extends the growing season

There are many designs of espalier, from a simple V-shape, to fans, crosses, Belgian fences and many more.  Some are curved or spiraled.

England is known for great gardens and akamai horticulture and they have one called a free-standing step over.  They do it with apple and pear trees and we can adopt this practice for our fruit trees here in Hawaii.

Mark Suiso of Makaha Mangoes is great proponent of mangoes and other fruit trees.  He encourages us to graft good mango varieties, prune them correctly and cherish every fruit. Recently he got us all re-excited about espalier.

Suiso and his ohana and friends have participated in Mangoes at the Moana for the last nine years.  We have learned and grown together and met many mango advocates.  It seems to me that we have more fruit these days and that more people are choosing to carefully prune and nurture their legacy mango trees.  People are planting new trees in their gardens.

It’s so important to support farmers, especially here in Hawaii.  To BUY a mango seems outrageous and not at all sustainable, please buy local!

After all, mangoes are the King (or Queen) of Fruit, just ask Queen Victoria (movie with Judi Dench, featuring her wanting to taste a mango from India)

P.s. I think we should try espalier with `Ulu or breadfruit too!  Horticulturists always love a garden challenge and what better one?

I espalier my mulberries, to keep them low for easy picking and out of my neighbor’s yard (they like the ‘golf course grass’ look) I also can net my fruit and protect them from the ravenous alien bulbuls and green escaped parrots that we have on Oahu.

In other places, such as Japan, Taiwan and Australia they do elaborate kinds of Horticulture including espalier to nurture and cherish every leaf, flower and fruit.  We could do this too!

I would love to hear from my readers, who are practicing espalier to nurture their own special fruit tree.  Please send pictures if you have them, we can all learn from and inspire each other.

Heidi Leianuenue Bornhorst is a landscaping consultant, gardener trainer and specialty VIP garden guide. She has been a professional horticulturist for more than 33 years and she is a Certified Arborist. You can contact her via email at or at 739-5594.

`Ulu aka Breadfruit, Healthy Food Production for Hawaii

Dear Governor Ige, Famers, and back yard gardeners, do you want to increase local Healthy food production?  Eat more nutritious locally grown safe food?  Breadfruit is one of the best solutions for sustainable Food security, better health, and natural beauty.

Breadfruit aka`Ulu is a beautiful tree with great Cultural significance here in Hawaii, and across the Pacific.  Hawaiians and many other local cultures have a long tradition (including varied recipes and preservation techniques) with breadfruit.

`Ulu has many

healthy body benefits, it is rich in fiber, calcium, potassium, B vitamins, and pro-vitamin A carotenoids. It is a “resistant starch”, it does not spike your blood sugar like white rice or white potatoes. If more people ate breadfruit we would cut down on diabetes and other health issues related to refined starch and high sugar diet.

When people tell me they don’t like the taste, I figure they have not had it properly cooked, or it was picked at the wrong time – too green or too ripe.  Yes, the over ripe smashed on the ground ones from an over tall non-pruned tree, are not too ono!

As a Certified Arborist, I recommend keeping backyard trees at a medium height for safe and easy harvesting via careful pruning starting after the first harvest (about three to five years in the ground).

If you have a farm, and a tree climber or cherry picker you can let the tree grow larger, but keep in mind, well-managed trees are far more productive.

Ulu or Breadfruit Tree

Ulu is a beautiful and simple tree to grow, harvest and care for. It’s easier to grow, harvest and cook than kalo (taro). There is no need to dig up and replant like root and tuber crops. `Ulu are highly regarded as pest and disease resistant, especially when grown in mixed plantings with other crops and useful plants.

For a number of years I have worked with and learned from Dr. Diane Ragone of the Breadfruit Institute (BFI) of the National Tropical Botanical Garden (NTBG).  We have given away over 12,000 keiki trees here in Hawaii and sponsored numerous breadfruit cooking contests. Our local participating chefs and gourmets are so talented and creative.


Chef Sam Choy is one of our amazing and totally giving back to the community Chefs.  For such a famous chef he is so humble, hard-working and just plain fun to partner with. We did the Wai’anae Eat Local Food Challenge, cook off and Breadfruit tree give away with him, Ragone, the Ho’oulu ka ‘Ulu project, and other community partners.

I have participated in numerous Arbor Day breadfruit tree giveaways over the years, these can be  like a feeding frenzy, everybody wants a free tree. Unfortunately not everyone who took a tree actually planted it.

Because our precious `ulu trees are propagated by tissue culture, we decided to make the process of getting one similar to adoption, hoping to attract people committed to and able to grow the trees. We asked people to promise to plant them in the ground within a few months, this gives the family time to make a decision about where in plant and to properly prepare the planting puka (clear away grass and weeds and use compost or stone mulching to make a clear area for the baby tree to thrive).

We utilize social media by sharing pictures and posts to reflect how well the keiki ulu trees are growing and producing healthy ono food.

Mahalo for all those who adopted a tree, keep sharing your feedback and great posts!

Helpful Growing Tips

How to plant:

  • Find a sunny spot away from wires
  • Clear away grass and weeds
  • Use hot mulch to help kill off the grass and weeds
  • Plant the keiki tree
  • Make a ring of mulch
  •  Water daily to establish
  • Replenish the mulch every few month

How to cook:

  • Harvest at mature firm green stage
  • Gently scrub and clean the skin (no need to peel)
  • Oil a big sharp knife
  • Slice ‘ulu into quarters
  • Steam for 20 minutes (or until fork tender)
  • Cool and freeze for future use

Or you can cook to your own liking, I make a simple curry with sautéed onions, garlic and Olena (turmeric).

Please check out the Breadfruit institute page on-line to learn even more about planting, harvesting cooking and the various varieties of ulu that we can grow here in Hawaii.

If you received a tree, please participate in our survey to let us know how your tree is doing.

You can also visit NTBG, they have gardens on Kauai, and Kahanu Garden in Hana that have amazing breadfruit collections for visiting and for inspiration. You can also join and support the NTBG in its important work on our “living library” of valuable trees and plants.

Learn more about when fruit is ready to harvest and how to handle in the Breadfruit Production Guide by Elevitch, Ragone, and Cole. 2014.  Available free   Download: or

Heidi Leianuenue Bornhorst is a landscaping consultant, gardener trainer and specialty VIP garden guide. She has been a professional horticulturist for more than 33 years. She is also a Certified Arborist. You can contact her via email at or at 739-5594.

Hawaii Succulents

Succulents are perfect for your Hawaii garden.

Succulent plants can be fun and easy to grow and care for.  They can even help protect your home and garden from wildfire.  They are less thirsty plants, perfect to conserve on water in our gardens and grow a Hawaii style xeriscape.  Some are perfectly adapted for our humid Hawaiian climate.

Others are not so good in Hawaii.  They may prefer a Mediterranean climate like that of California.  These may grow OK at first here in Hawaii, and then they “melt”.  They just wither and fade away and …. It’s NOT your fault!  Ice plant is an example of one of these plants. Native to South Africa, it will grow a year or two in Hawaii, seem to be doing well and then fades away.  We had a nice planting of it at the Halawa Xeriscape Garden on a slope, but its pau now.

Aloe and Jade plants are some of our best gel filled plants for Hawaii gardens.  Not only are they tough and easy, but they also will reward you with a flower now and then.  (Many of our Aloe species bloom in our Hawaiian winter, sending up a pretty lily-like orange or red flower spike).

We also have many epic native Hawaiian succulent plants.  Hinahina the Lei Flower of Kaho’olawe is one of the most beautiful.  It’s tough in the wild, in harsh HOT, ehukai air filled areas.

Our native Hawaiian `ihi or Portulaca species are succulent and tough, with very pretty flowers. Portulaca molokiniensis is one of the most striking, with clusters of golden yellow flowers and a squat succulent growth habit.

`Ala`ala wai nui our Hawaiian Peperomias are also a cute succulent plant with many native species from various dryland and wetland habitats.  In wet places, they can grow happily on big pohaku or boulders, or epiphytically up in trees. These native habitats have perfect drainage.  Something we need to try and horticulturally replicate when we grow them in our gardens.

If you live in a wildfire prone area, you might consider a low scape including succulents. You can find many that are native to and grow well in Hawaii.

In a classic succulent vs fire story from California, a huge wildfire was sweeping through a San Diego, California neighborhood, many homes and gardens were destroyed.  Yet one (artist) lady had grown a low maintenance garden full of succulents including Aloe. It was a giant Aloe plant that is credited with helping save her house.  Though it burnt and appeared dead, its heart was full of moisture and the water stored in its tissues slowed the fire long enough to save the home.  The aloe also survived and with time revived after the fire.

Coastal and dry forest plants have adaptations to survive and thrive in hot dry salty windy areas.  Portulacca molokinienis or Molokini `ihi is one of the cutest, with a fat stalk, rosettes of succulent leaves and clusters of golden yellow flowers.

We have other native Portulaccas, which we call `ihi.  They can have white, pink or yellow flowers.  Most are easy to grow from cuttings.  They can also be grown from seeds.

Hinahina, the lei flower of Kahoolawe has the most gorgeous silvery rosettes of leaves and curled flower spikes of tiny white fragrant flowers.  Super gorgeous in the garden and very xeric once established.

The rare Alula, Brighamia citrina, native to the pali, steep cliff areas and today found only along Kalalau on Kauai, is being saved by gardeners who love its fat stalk, clusters of leaves and long tubular fragrant blossoms.

All of these native Hawaiian succulents need slug and snail protection.  Surround them with coarse black or red cinder, egg shells or a ring of used coffee grounds.  Copper strips and food grade diatomaceous earth also help to repel slugs and snails.

Gardener vigilance is good too.  Check on them at night or after heavy rains and manually remove slugs using a plastic bag to grab and then dispose of them.  Or do like my kolohe neighbor does, poke ‘em jubilantly with his old fishing spear and then dunk them in a bucket of soapy water, then bag them into the trash bin.

Heidi Leianuenue Bornhorst is a landscaping consultant, gardener trainer and specialty VIP garden guide. She has been a professional horticulturalist for more than 33 years and is a Certified Arborist. You can contact her via email at or at 739-5594.