Friday, October 28, 2011

Where to Get the Best Information

 The Cooperative Extension Service of University of Hawai`i at Manoa, College of Tropical Agriculture and Human Resources (CTAHR) is an excellent source of factual, scientifically based information for commercial growers and homeowners alike.  In Hilo, CTAHR is located at 875 Komohana Street, their phone number is (808)981-5199.  They have both free and priced publications on subjects from Abiu to Zucchini and from Anthurium to Ulu.   Check out their excellent website at www.ctahr.hawaii.edu 
The Extension Office in Kona is in Kainaliu at 79-7381 Mamalahoa Highway; and in Kamuela at 67-5189 Kamamalu Street across from Church row.  In addition, O`ahu, Maui and Kauai have Extension Offices.
Search the web for University Cooperative Extension Offices in your state. Often times a University Master Garden Program is located at the Extension Office. Master Gardeners have a wealth of knowledge for backyard gardeners. In Hilo, call them at (808) 981-5199, Monday, Tuesday and Friday from 9 AM till noon. You might also want to inquire about how you can become a Master Gardener. 

Wednesday, October 26, 2011

Growing Your Own Tea

Whether oolong, green or black, teas are all made from the same plant, Camellia sinensis.  It is the processing that makes the difference: withering, fermenting, heating and drying. The fermentation combines various oxidation and enzyme reactions which contribute to the teas unique flavors.  The least processed teas, like some of the Chinese and Japanese green teas, are the un-oxidized teas. The partially oxidized teas include the paochong and oolong teas.  An example of fully oxidized tea is the familiar black tea or English tea.
Anyone who enjoys a good spot of tea should try growing and processing their own.  Even with a small yard, one or two plants will do nicely.  The processing can be a bit time consuming, but even if you choose some short cuts, you can still enjoy a nice, mellow cup of green tea.
Hawaiian grown tea has come a long way since its introduction in 1887.  Since then, a number of business adventures had begun but were eventually abandoned for economic reasons.  In 1997 renewed interest in tea culture began on the Big Island with the development of a novel small-scale processing technique developed by USDA horticulturist  Dr. Francis Zee.  In 2002, the Hawai`i Tea Society was founded by tea growers and enthusiasts alike and offers educational programs in tea culture. 
Backyard enthusiasts can purchase tea plants at most local nurseries.  The tea plant, Camilia sinensis, is a close relative to the ornamental camilias, Camillia japonica and C.sasanqua. The ornamentals are generally 4-6 ft. tall shrubs.  Tea plants are usually pruned to about 4 ft high but can grow as tall as 40 feet.  Tea plants like acidic soils that are well drained.  They also like full sun yet can thrive in foggy environments.   Although tea plants have a natural resistance to many pests, the Chinese rose beetle along with various mites and scale insects may still be a bother. 
The Cooperative Extension Service has a number of excellent publications on growing tea including Guide to Insect and Mite Pests of Tea in Hawai’i and Small-scale Tea Growing and Processing in Hawai`i. If you wish to contact the Hawai`i Tea Society, their website is www.Hawaiiteasociety.org

Monday, October 24, 2011

Planting cool season vegetables

Where seasons are distinct, gardeners traditionally grow warm season vegetables during the summer months while cool season vegetables are more commonly grown in the cooler part of the year. The root systems of cool season vegetables are commonly shallow; their seeds germinate at cooler temperatures and in general, are more adapted to grow in cooler weather.  In addition, the harvested crop is more tolerant to chilling injury.
In Hawai’i there is the opportunity to plant and harvest many different kinds of vegetables all year long. However, some vegetable plants will definitely do better when planted within a given time frame.  Late summer, early fall is a good time to begin planting cool season vegetables: beets, broccoli, cabbage, carrots, celery, chard, kale, leaf lettuce, onions, peas, potatoes and turnips. 
Some vegetable crops run into trouble when planted out of season. Lettuce is a good example.  It is a cool season vegetable and as long as the temperatures remain cool, the lettuce plants will continue to produce tender leaves. Generally lettuce is planted from September through March.  During the hot summer months the plant bolts, that is, begins to flower and seed. This principal is also true for other vegetables like broccoli and head cabbage.  Gardeners living at higher elevations may be successful planting some of the cool season vegetables such as cauliflower, chard and mustard in late spring and summer.  
Experiment with a wide variety of vegetable plants, even warm season vegetables in the winter and cool season ones in the summer.  You will soon learn what works best for your climate zone.

Friday, October 21, 2011

Banana Fertilization

 In general, banana plants need a fertilizer with high amounts of potassium (K), along with nitrogen (N) and phosphorus (P).  Soils vary around the Islands, some being richer than others. The University of Hawai`i recommends applying 2 lbs., three times a year of a fertilizer similar to 10-5-20 (N-P-K).  This amount is applied per mat. When referring to bananas, a group of plants is known as a mat. A properly maintained mat will have one plant in fruit, one plant half-grown and one plant just emerging from the soil.
Applying compost to the surface of the banana mat is beneficial, but most likely will not supply enough nutrients, especially nitrogen, for optimum growth. 

Wednesday, October 19, 2011

Fruit Flies

 Have you ever cut into a nice piece of juicy ripe fruit only to find a bunch of wiggly, white worms staring back at you?  Most often, these are the larvae of fruit flies.  Because of them, many growers and homeowners alike find it very difficult to grow certain crops.  The four fruit flies we have on the Big Island have a choice of over 400 plants to infest.

 Oriental fruit fly –Introduced in 1945, it ranges from sea level to 4,000 ft and likes citrus, guava, mango and papaya and others. 
Mediterranean fruit fly –Introduced in 1907, is common at 1,000-4,000 ft and likes citrus, coffee, papaya, guava and others.  This fruit fly is common in coffee groves.
Melon fruit fly – Introduced in 1895, is found from sea level to 15,000 ft and likes melons, squash and cucumbers, as well as eggplant, pepper and tomatoes.
Malaysian or Solanaceous fruit fly – The newest addition to our group of fruit flies came here about 10 years ago.  It ranges from sea level to 1,500 ft. and prefers solanaceous plants – tomatoes, peppers, eggplant.

Although we won’t be able to eliminate these pests, there are a few things we can do to suppress their population. 
·        Sanitation – pick up all dropped fruit and discard. 
·        Attractants - there are special attractants available that will lure the males to a baited trap. This not only tells you what species of fruit fly you have, but also removes the males from the breeding cycle. If it is a new infestation, these traps can possibly catch enough males to reduce the population. 
·        Baits - the use of protein bait sprays with a toxicant such as GF 120.

Since infested fruit can harbor 100’s of fruit fly larvae, do not place them in your compost pile.  Or, if you do, put them first in a sealed plastic bag for 45 days, then you can put them into your compost pile.  You can also bury the fruit – at least 18 inches.  Feeding the fruit to animals is OK too.
Fruit fly brochures are available at local CTAHR Extension offices.

Monday, October 17, 2011

Whiteflies

They are not only a menace to our gardens, but to commercial agriculture as well.  There are more than 1,000 whitefly species in the world. Twenty species occur in Hawai`i; 12 of which have been accidentally introduced in the last 20 years.  They attack citrus, avocado, plumeria, poinsettia, anthurium and a whole host of vegetables and other ornamentals. As you approach heavily infested plants, clouds of adult whiteflies fill the air. 
The adult whiteflies, which are not true flies at all, look more like tiny, white moths.  They are sapsuckers, continually drawing off water and nutrients from plants, causing leaves to yellow, shrivel and drop prematurely.  Eventual death of the plant can occur.  Whiteflies also transmit several viruses. In addition, they cause an indirect decline of the plant by their heavy excretion of a liquid, rich in amino acids and sugars, called ‘honeydew.’  This liquid is constantly dripping to coat the leaf surface below, which is soon colonized by a common airborne fungus, called sooty mold. Although the fungus itself does not invade the leaf tissue, the leaf quickly becomes black and dirty looking, restricting respiration and photosynthesis in the plant.
Gardeners have great difficulty in controlling whiteflies, because they are so prolific. Another reason is that the different stages of growth of this pest have varying degrees of susceptibility to pesticides.  This means that after you spray, only a portion of the whitefly population died.  Therefore, repeated spray applications are needed.  Also, some whitefly populations have developed resistance to pesticides.
The application of broad spectrum pesticides to control whitefly is generally not recommended, because this kind of spray has harmful effects on natural enemies (the good guys). Broad spectrum pesticides are those that affect a wide range of insects as opposed to those which affect the target species only.

So what do we do?  First of all, if your tomato or bean plants are heavily infested, throw them away.  If a shrub is heavily infested, severely prune, and deal with the new population while it is still small.  Here are some other tips:
·        Yellow sticky cards – These should be placed adjacent or just above the infested plants – one card per 2 plants.  They have good potential for controlling light (or new) infestation. The insects are attracted to yellow and will stick to the card when they land.  Once the population has built up, however, the cards are not very effective.

·        Syringing - Apply a strong stream of water at the underside of infested leaves as often as possible.  This will wash off many of the whiteflies, as well as the honeydew.  University of California studies have shown this method performs as well or better than chemical treatments.

·        Pruning – Prune away severely infested portions of the plant.  Place material in sealed plastic bags and dispose of properly.  Keep in mind that excessive pruning stimulates much new growth, which is attractive to whitefly.

·        Ants – Ants are a detriment to biological control and must be eliminated. The ants are bigger than many whitefly parasites and, by their aggressive behavior, will discourage the good guys from the scene.

·        If you spray, use insecticidal soaps and horticultural oils; this  minimizes the adverse effects of harsh pesticides on the natural predators and parasites. 

·        Aluminum foil or reflective plastic mulches have been shown to repel whiteflies, especially away from small plants. 

Many parasites and predators of the various whiteflies have now been identified. Some of these have been imported from other parts of the world.  Here in Hawai`i, as well as in other states, parasites and predators are doing a good job in controlling this pest.  They will not eliminate the whitefly, nor are they an instant control.  And, for various reasons, whitefly can flare up and ruin a good crop. But a healthy population of natural enemies enables us to garden with little or no apparent damage to our plants. Controlling the ants and keeping dust to a minimum is important in encouraging the natural enemy population. 

Friday, October 14, 2011

Slugs and Snails


What to do about these pesky slugs?

Even though there are nine different varieties of slugs and about two dozen varieties of land and freshwater snails, all it takes is a few in your garden to devour a newly planted seed bed.  Slugs thrive in humid and wet places.  They commonly feed on decaying vegetable matter, leaves, flowers, trunks and roots, but they will also feed on earthworms, molds and dead insects. Slugs are nocturnal and seek shelter underneath rocks and boards and in damp refuse and mulch.  They are extremely susceptible to drying out. 

There are several different ways to control slugs and snails.
·        Biological – There are many natural predators of slugs including toads, predacious beetles, birds, ducks and chickens. 
·        Mechanical –  Trap boards are an easy way to rid the garden of slugs.  Simply place a board, any manageable size, near slug activity.  Place one end of the board on a small rock, or another object in order to give it enough lift for the slugs to crawl under.  This board then becomes a good hiding place for the slugs.  After a few days to a week, turn over the board and see how many slugs are resting underneath.   Discard slugs in a manner of your choice.  

Gardeners can also collect slugs early in the morning or in the evening to reduce their numbers. Copper screening or foil placed around items like flower pots, raised beds and greenhouse table legs will keep slugs out. 
 Beer traps (small cans buried at ground level filled with beer) are popular in ridding the garden of slugs and snails. However, this method is not very effective for the labor involved.  The traps attract slugs within an area of only a few feet, and must be refilled every few days.  It is the fermented product that attracts them, so a sugar-water and yeast mixture could be used in place of beer.

·        Cultural – A cheap and safe method of controlling slugs, although not always practical, is sanitation.  This involves eliminating their hiding and breeding places by raking up the leaves, discarding boards, logs and other such debris.

·        Chemical – Baits containing the active ingredient metaldehyde are very effective in controlling slugs.  Be careful when using these products around pets.  If pets ingest this bait, it can be fatal.
Other products, with the active ingredient iron phosphate, are also effective against slugs.  According to their label, they can be used around pets and wildlife. When using these, and any other pesticide, always read the label carefully, and follow all instructions.

Wednesday, October 12, 2011

Blueberries

Can we grow blueberries here in Hawai`i? 
With all the talk recently about the health benefits of blueberries, I can understand why many people are wondering if they can grow blueberries here in the tropical, blue Pacific.  Most of us think about the cold Northwest where many blueberries are grown. Actually, there are three main types of blueberries grown throughout the continental United Sates: Rabbit-eyes, low-bush, and high-bush varieties.  Now, thanks to the University of Florida’s hybridization program, there are a number of new varieties that will grow well in warmer climates like Florida and California…. and  Hawaii.

California’s Agricultural Extension Service began researching blueberries in the 1990’s. Today California has over 6,000 acres, producing 14 million pounds of fruit, which is low compared to the 100 million pounds produced in Michigan.

Blueberries grow best in moist, well-drained, acid soils.  They also like humidity.  The bushes grow 6-8 feet tall and about 4 feet wide. They do best in a cooler climate, thus a higher elevation may be more conducive.  It is recommended to plant blueberries on raised beds that are 8 – 18 inches high and 3 - 4 feet wide to provide additional drainage and aeration. After planting, apply mulch such as woodchips or other organic material. Mulch helps to keep the soil cool and conserve moisture. It adds organic matter and controls weeds. 
Blueberries are free standing and require no trellis.  They have a shallow, fibrous root system and are susceptible to drought.  Pruning is important. . Blueberries also do well in containers.

The three most common problems encountered are birds, Chinese rose beetles and a rust disease. The birds, waiting for the berries to ripen, can be deterred with netting.   The severity of the rust is reduced by growing plants under cover to keep the rain out. Promptly removing diseased leaves will also reduce disease pressure.   Fruit flies do not seem to be a problem yet.

Among the many varieties of blueberries there are six being evaluated at the Mealani Research Station located in Waimea at an elevation of 2800 feet above sea level: Biloxi, Emerald, Sharpblue, Sapphire, Jewel and Misty. Jewel and Misty gave the least yields. Sharpblue produced the sweetest fruit, but all were well received in informal taste tests. Some reports state blueberries are growing reasonably well at 1000 feet.   Plant a number of different varieties and see which ones perform the best for your particular area.
Some plants can be purchased from mainland nurseries in Oregon, Michigan and other states but may require a large quantity purchase.  

Ask the Garden Guy, Science Based Answers to Garden Questions, is an excellent resource book for gardeners. Some popular topics include Slugs and Snails, Organic Pesticides, Reasons, Why Vegetable Seeds Do Not Germinate, What’s So Hot about Manure? Mushrooms in the Lawn.  Purchase by clicking on the image of the book above. 

Monday, October 10, 2011

Planting Avocado Seeds: Will the Trees Produce Good Fruit?




The seeds will grow into a nice tree, but it is uncertain what type of fruit the new tree will produce, even if that seed came from a great tasting fruit. The best way to propagate an avocado tree is through grafting.

 Most commercial avocado trees are grafted.  The grafting material, called a scion, is basically a green twig taken from a tree of known, good quality fruit called the mother tree.  This scion is then grafted onto a young seedling, perhaps a year old.  All the fruit that is produced from this new tree will be identical to the fruit borne on the original mother tree.  When a grafted tree is purchased, the exact type of fruit is known.  On the other hand, when planting an avocado seed, the type of fruit that will result is unknown due to gene mixing. In fact, it is through the gene mixing that new varieties are discovered.   It is possible to produce a high quality fruit, but unlikely. What usually occurs is the seedling tree will produce small fruit with a large seed. 

For instructions on grafting, go to the University of California website, http://anrcatalog.ucdavis.edu, and search avocado. There is an excellent publication called Budding and Grafting Citrus and Avocados in the Home Garden.