Monday, October 28, 2013

Propagation of Blueberries

Blueberries are propagated from either softwood or hardwood cuttings. 

Hardwood cuttings  are collected in late January or February, after sufficient chilling has occurred.  1. Select healthy material. 2. Avoid propagating from plants that have odd-looking or stunted foliage. 3. Collect shoots from the previous summer, 12 to 36 inches in length.  4. Divide these shoots into pieces 5 to 6 inches long, removing any flower buds. 5. Place cuttings in a propagation bed at a depth of one-half to two-thirds of their length. Keep moist.

Softwood cuttings are taken in late spring from the current season's growth, 4 to 5 inches long.  Collect these cuttings when the stems have developed woody tissue but are still somewhat flexible. Remove all leaves with the exception of two or three terminal leaves.  Place cuttings in the propagation bed, under mist at a depth of one-half to two-thirds of their length.

Rooted cuttings are eventually transplanted into pots and held for about one year.   During the time of rooting, keep beds moist while being aware not to over water.
A greenhouse is not necessary, but some type of propagation bed/chamber, under 40 to 70 percent shade with a mist system is recommended; an area as small as 3x3x3 can be used.

The mist system should keep the media uniformly moist but not soggy.  An intermittent-mist system with frequent, short misting intervals is recommended in order to keep the humidity near 100 percent.  However, keeping the cuttings at this constant moisture also creates an ideal environment for pathogenic fungi to grow. Thus cleanliness is very important; use new or sterilized planting mix and pots, keeping them raised off the ground.

Potting media containing various mixtures of coarse sand, ground pine bark, perlite, sawdust, and peat moss have proven satisfactory.  One such recipe is a mixtures of coarse sand, ground pine bark, and peat moss (1:1:1) and perlite and peat moss (1:1)

Monday, October 21, 2013

VOG Equals Hawaiian SMOG

People living in the Los Angeles, California Basin have known for years that smog affects plants.  There exists a similar situation on the Big Island of Hawaii. It’s called VOG, emissions that spew from the Kilauea Volcano at Halemaumau. The discharges include sulfur dioxide, sulfites, ash and hydrochloric acid.

 Many gardeners, especially those living near the Volcano area, have experienced the distressing effects of vog on their plants.   Sulfur dioxide  enters the leaf through the stomata.  The degree of injury will depend upon its concentration and duration, and upon the sensitivity of the specific plant. The symptoms of low concentrations of sulfur dioxide are general chlorosis (yellowing) of the plant foliage. Higher concentrations cause a bleaching or browning of tissues between the leaf veins.

Volcanic ash appears as a dust and is composed of fine rock particles from the volcano. The ash does not damage plants directly but can block sunlight on foliage as well as detract from the appearance of the plant. Harvested fruits and vegetables should be thoroughly washed prior to their consumption.

There is not much that can be done about the harmful chemicals the volcano churns out. As far as the plant is concerned however,  leaves should be rinsed with adequate water after exposure. Susceptible plants can be grown under cover such as greenhouses, and during periods of intense vog, valuable plants can be temporarily covered with fabric or plastic.

Different plants have varying degrees of susceptibility to vog.  Here is a list of plants documented to be susceptible to vog:
Ornamentals - African lily, Oriental lily, cypress, Dutch iris, eucalyptus, ginger, hydrangea, heavenly bamboo, pine, podocarpus, rose and tuberose.
Native plants -  koa, naio, pilo, uki, akala.
Vegetables - broccoli, cauliflower, Chinese cabbage, daikon, lettuce, Swiss chard, tomato and watercress.

Some of the more resistant plants are asparagus, celery, coffee, corn, and ohia.

For a more in depth look at the volcano’s effects on plants, with some excellent photographs, read, “Volcanic Emissions Injury to Plant Foliage”, by Scot Nelson and Kelvin Sewake, UH Department of Plant and Environmental Protection Sciences. The publication can be found on the CTAHR website -

Monday, October 14, 2013

Little Fire Ants

The sting of the little fire ant (LFA) is very painful and produces red welts. With some people, welts last as long as three days with aching pain, and later intense itching. 

LFA are tiny (about 1/16 inch long), pale orange and move rather slowly.  They are highly adaptive. They live in the open or under shade, in areas of 10 inches of rainfall to over 100 inches, they are found from sea level to 1700 feet and can nest on the ground or in trees.  They eat just about anything. They can remain up in the tree, or they may move up and down. They will also infest homes under carpets and along baseboards.

Control Measures
 For controlling LFA, researchers recommend a three pronged attack and a whole property approach; spot treating is inadequate. 
1.  Place ant baits in infested areas.  In general, this is done to control ground nests.  The ants will take the bait back to their nest and share it with others. Baits are the front-line tool for ant control.  This approach should be tried first. Wait a couple weeks before applying barrier treatments. 
2.  Barrier treatments – the application of insecticides (liquid or granular) around areas where ants need to be excluded.  As ants crawl over the treated areas they are killed. The more ground you treat, the better. However, if you want to limit your use of chemicals, treat those areas where you want the most protection, areas most used by people and pets.  
3.  Ants nesting in trees may not be controlled by bait applications. Therefore a foliar insecticidal spray, applied to infested trees and vegetation, is needed.

  •  Suitable baits for Little Fire Ants -For step 1  Amdro, Probait, Maxforce Complete, Extinguish Plus (reported as moderately attractive) and Tango, a new product recently registered in Hawaii. Even though the products Extinguish Pro and Esteem Fire Ant Bait are registered for use on many food crops, they are not highly effective; see website below. Tango, on the other hand, is registered for use on food crops and is very effective and safe.
  • Suitable barrier treatments For step 2  Products with the active ingredient bifenthrin (examples, Ortho Home Defence Max granules, Ortho Home Defence spray and others)
  • Suitable chemicals for foliar spraying and drenching potted plants –  For step 3   Look for the active ingredient carbaryl (examples, Eliminator            Bug Killer Sevin Concentrate, Gardentech Sevin Concentrate Bug Killer  and others)

If you suspect that you may have the LFA, coat a chopstick, or any small stick, with peanut butter and stick several in the ground around your property.  If any ants are caught on this bait, take them to the Hawaii State Department of Agriculture at 16 E. Lanikaula St. in Hilo for positive identification.

In addition to the information presented here and for more detailed information, I refer you to an excellent LFA website It was put together by Cas Vanderwoude, a researcher with the Hawaii State Department of Agriculture.   Furthermore, check out the latest research on Tango. Although this product is expensive, it is thought that applications of Tango may control ants well enough that steps 2 and 3 can be eliminated.  Tango is an insect growth regulator (IGR). This type of product works by preventing the insect larvae from completing their pupation process. It also slows down egg production by the queen. Information and directions for making the new gel bait (Tango) are on the website.

Monday, October 7, 2013

Breadfruit Food for a Famine

 It is thought that breadfruit trees spread throughout the Pacific Region by migrating Polynesians and were brought from the Samoan Island of Upalu to Oahu in the 12th Century. Its common name in Hawaiian is ulu, as it is also in Samoa, Rotuma and Tuvalu. The fruit is a staple food in many Pacific Island cultures.

The Movie
Some will remember the movies, Mutiny on the Bounty, and The Bounty. Did you know it was all about breadfruit? Due to several famines in Jamaica between 1780 and 1786, plantation owners in the British West Indies petitioned King George III to import breadfruit trees in order to provide a food source for the slaves. Captain Bligh sailed to Tahiti in 1787 to obtain breadfruit plants to transport them to the British West Indies. On that calamitous voyage, he lost 1,015 potted breadfruit plants. Was the true reason for the mutiny the fact that he rationed water to his crew in order to give ample water the plants? Was Captain Blight a true gardener at heart? For more details, see the movie or read the book.  After being forced overboard in a nineteen foot cutter, Bligh miraculously navigated himself and some of his faithful crew to safety, crossing almost 4,000 miles.

 After returning to England, Bligh set sail again, in 1791, for Tahiti, and this time he was able to successfully deliver 5 different varieties of breadfruit trees, totaling 2,126 plants, to Jamaica in 1793.  The trees flourished and were subsequently planted in other islands of the West Indies as well as Central America and northern South America. Ironically, it is reported that the slaves rejected the fruit. But today, Bligh is revered as a hero in Jamaica.

Breadfruit trees are medium sized, growing to about 50 tall at maturity. There are hundreds of different varieties of breadfruit, both seeded and seedless types. It is truly a tropical plant, more susceptible to cold than the mango. The breadfruit tree is best grown in deep, fertile, well-drained soil. The optimal growing range temperature is 60° to 100°F.  Due to the large number of different varieties of breadfruit, however, trees do exhibit a wide range of adaptability to ecological conditions.

Seeded breadfruit varieties can be grown from seeds. But it has been noted that they do not run true to type. Seedless breadfruit is often propagated by transplanting suckers which spring up naturally from the roots. Pruning the tree will increase the number of suckers produced, as will exposing and injuring a root. New branches and shoots can also be air layered.

Breadfruits are abundant in Hawaii from July to February.  Fruit is picked when mature, which is indicated by the appearance of small drops of white latex on the surface. Breadfruit can be eaten before it is ripe, as a vegetable, or eaten as a fruit when it ripens.  For the former, it is picked while still starchy and is boiled or roasted. Fully ripe fruit are sweeter and often baked whole. The seeds are boiled, steamed, roasted and eaten with salt. The leaves are eaten by domestic livestock.

Breadfruit is high in carbohydrates and a good source of fiber, vitamins and minerals. The trees are relatively free of pests and insects; fruit flies will infest ripe fruit. The following websites contain an abundance of information for an in-depth study of breadfruit trees.  

Photos by Forest and Kim Starr