Monday, December 29, 2014

Cotton in Hawaii



In Hawaii, the cotton plant, Gossypium tomentosum, is a perennial shrub lasting about 3-5 years, depending on growing conditions. In Hawaiian, it is called Ma’o. This plant can be found growing in coastal plains and dry forests primarily on the leeward sides of the main Hawaiian Islands. Ma'o naturally grows in hot, dry, windy coastal areas tolerating the salty spray. Conversely, the plant does not do well in locations with continuous high rainfall and in waterlogged soil.

Periodic pruning is necessary to control the height, to keep the shrub full and to prevent low lying branches from spreading.

In 1838, a commercial cotton industry was actually started in Kailua on the Big Island of Hawaii. Although it lasted for about a century, cotton never became an important trade item. Even though early Hawaiians stuffed pillows with the fibers, the cotton was not used as a fabric. 

 For more information on Ma’o, see the website for native plants in Hawaii at  http://nativeplants.hawaii.edu/plant/view/Gossypium_tomentosum 
and refer to the UH CTAHR publication entitled, “Ma’o (Hawaiian Cotton). 

Photos by Forest and Kim Starr

Monday, December 8, 2014

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. Follow these simple directions: collect shoots from the previous summer, 12 to 36 inches in length. Select healthy material, avoid propagating from plants that have odd-looking or stunted foliage. Divide the shoots into pieces 5 to 6 inches long, removing any flower buds. Place cuttings in a propagation bed at a depth of one-half to two-thirds of their length. Finally, keep moist.


Softwood cuttings are taken in late spring from the current season's growth, 4 to 5 inches long. Here are the directions: 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.
For the propagation process, 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. According to a publication from the University of Hawaii, a good rooting medium recipe is a mixtures of coarse sand, ground pine bark, and peat moss at 1:1:1, or perlite and peat moss at 1:1.



Monday, December 1, 2014

Spittlebugs



Are your plants foaming at the leaves?

A white frothy substance on plants may be a spittlebug. Inside all that froth is a tiny bug about ¼ - ½ inch long.  The immature stage of this insect sucks the plant juices just as aphids do. But in the process, spittlebugs remove so much water and carbohydrates, that excess fluid is produced. They then cover themselves with this fluid. The spittle is produced when the insect bubbles air from the tip of the abdomen into the liquid. This is an ingenious method to protect themselves from predators and  from drying out.

Although the removal the plant fluids can weaken the plant, rarely are spittlebugs a serious problem. Simply spraying a strong stream of water can physically remove the pest. A soap/oil spray can also be used.

In addition to basil, the spittlebug attacks other common plants such as rosemary, mint, hibiscus and some pine trees.