Ohia lehua is one of our most amazing and cherished native Hawaiian plants. Symbolic and special, it is prized by lei makers, hula practitioners and native Hawaiian plant lovers. But the trees are threatened by a new and devastating alien disease. This is so sad.

For years we have tried to get a ban on importing members of the same plant family, Myrtaceae, to help protect ohia lehua. These relatives could harbor insects and other pests, or even worse a fungus, bacteria or virus that is not easy to see. For example, florists like to import silver dollar eucalyptus, a tough relative of ohia that could be infested with pests to which ohia has no resistance. These pests could spread to our native forests and wipe them out.

Now the threat is more critical as a new fungal pest is wiping out ohia forests on Hawaii island. A quarantine has been imposed on carrying ohia between islands. Let’s hope it’s not too late.

Let’s hope some of the trees will be resistant to the pest, or that our akamai researchers can find a cure. J.B. Friday is a lead researcher into this disease, called rapid ohia death or Ceratocystis wilt. The pathogen, Ceratocystis fimbriata, is a vascular wilt fungus — that means it clogs up the vascular system, the "veins" of the trees, which transports water and nutrients to keep the plants alive.

The trees suddenly dry up and die. Insects may transmit the disease. Boring insects are suspects, but we really don’t know. In some forests 50 percent of the trees are dead or dying.

We need to respect the quarantine and not try to bring back any ohia lehua plants, flowers, liko (leaf buds), branches or soil from the Big Island.

To reduce the spread of Ceratocystis, the wood of affected ohia trees should not be transported to other areas, as the pathogen may remain viable for more than a year in dead wood. Tools used for cutting infected ohia trees should be cleaned either with Lysol or a 70 percent rubbing alcohol solution. A freshly prepared 10 percent solution of chlorine bleach and water can be used as long as tools are oiled afterward, as the bleach will corrode metal. Chainsaw blades should be brushed clean, sprayed with cleaning solution and run briefly to lubricate the chain.

Vehicles used off-road in infected forest areas should be thoroughly cleaned underneath so as to not carry contaminated soil to healthy forests. Shoes, tools and clothing used in infected forests should also be cleaned, especially before being used in healthy forests.

In recent years, horticulturists have figured out how to grow ohia in home gardens so we don’t need to pick from the wild.

I got an email from my friend Leilani on Oahu, and she needed kokua for an upcoming community event. Folks usually went to the Big Island and collected ohia flowers and liko to make lei. But because of the ban, they could not do this. I offered her some from my garden — although due to all the rain, mine are not flowering much right now, but my liko is lovely.

If you live on the Big Island and want to see if your trees carry the fungus, take a sample to be tested. You can view a short video on how to do this. Warning: Injuring ohia trees like this may kill them. Be sure the tree you are cutting is already dying. On Hawaii island, samples may be submitted to Lisa Keith, U.S. Department of Agriculture, Agricultural Research Service, Daniel K. Inouye Pacific Basin Agriculture Research Center; Lisa.Keith@ars.usda.gov; 808-959-4357. On other islands, samples may be submitted to the Hawaii Department of Agriculture Plant Quarantine Branch.

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