Forestter Blog

We often find ourselves worried about storm damage as hurricane season approaches in June. Hurricanes can cause tremendous damage on the rare occasion that one comes our way, but they are few and far between. The facts show that on an annual basis, we have more cumulative damage due to high winds and rains from storms from February through March. This means now is the time to do the pruning required to keep our trees healthy. What we have learned from storms when a cold front comes from the Gulf of Alaska with high winds, is that the major damage done from actual winds was to trees like lychee, macadamia, mahogany and other broadleaved trees. However, palms like Coconut, Royal, Cabbage Palms, Mexican Fan Palms, Pritchardia and scores of others survive the storm winds. Many will tolerate flooding with little damage as well. If the soil was so soggy that the palms tipped over, they were easy to replant and recover. Since there are hundreds of species, the question is — which palms can be used to create your tropical landscape with a minimum of storm damage and care? The Hawaii Island Palm Society is available to help folks answer that question so check out their website. The UH College of Tropical Agriculture and Human Resources master gardeners help line can also be of service. In East Hawaii, call 808-981-5199. In West Hawaii, the number is 808-322-4893. When it comes to trees other than palms, remember they are important elements of parks, streets and home gardens. Do not forget that they supply oxygen, sequester carbon and in general are helping to minimize the negative effects of global climate change. However, they do require proper maintenance to ensure they make it through stormy weather. It is always important to inspect your trees for dead branches that seem to be ready to fall. A gust of wind can snap an arm-size branch from a tree and send it at missile speed through a picture window. A low hanging branch over a roof can wreak havoc. Powerful winds can turn the limb into a tool of destruction. This tool can remove shingles as easily as a fish can remove scales. Removing dead and out of place limbs is a good idea even if there is no storm. Fan-like fungus growing on the side of a tree trunk indicates rotten spots that need attention. A hole made by poor pruning, damage from earlier storms, or the gouge of an auto bumper can start rotten spots. Remove decayed trees that are too weak to hold up under the strain of a storm. This action will save you grief later. Actually, even a 60-mile-an-hour wind is not as dangerous as it sounds if necessary measures are taken before the wind reaches gale force. If your home is located in an area that might be flooded, you’ll be given ample notice to evacuate hours before the storm reaches your area. Otherwise, there is no safer place than in a well built home. Once the storm has passed it is a good idea to inspect the trees and other plants around the house. Usually all the plants will show signs of wind damage. With a little trimming, propping, resettling of root systems, fertilizing and watering, nearly all plants that were shaken loose from the ground can be salvaged. After March, it is a good idea to consider root pruning as a way to manage those larger trees. If in doubt on what to do, you may contact a local certified arborist to assess the situation and correct it. Many of our tropical trees grow rampant with extensive root systems. That is why we prune to keep them from getting out of hand, but let us prune the right way. Late spring and summer are not the best time for heavy pruning since shade is at a premium during those hot days ahead. February is a good time as the days are getting longer but the sun’s rays are less intense than after March when spring and summer are upon us. In conclusion, remember that trees are vital to making urban life healthier for us physically, mentally and even spiritually. Forest fires, storms and drought are destroying our forests on a global scale. On the other hand, every time we plant a tree, we help to minimize the effects of global warming. Enjoy those beautiful trees in your garden by maintaining them correctly. On a grander scale, work with Hawaii County and State governments to plant more trees in parks, roads and highways. We depend on the tourist industry. Visitors to our islands as well as residents appreciate our beautiful landscapes. Without trees, this would just be another barren desert island. Palms, because of their beauty and tenacity make a great choice.

In the good old days, a typical Hawaiian garden was large enough to give neighbors plenty of space to have privacy. As our population increases and land costs escalate, lots are getting smaller. This requires creativity to effectively give us a little garden peace and quiet. Traditional garden designs of Japan have dealt with these issues over the centuries. A trip to Japan would be great, but we can learn by observing how local landscape architects and designers have addressed these challenges. A key element in designing for privacy is to create buffers between your home, neighbors and roadways. “Good fences and hedges make good neighbors” goes the old saying, so consider hedges to block unwanted sounds and views. There are many choices. You can use one species like orange jasmine or natal plum, but be sure that the choice does not require constant pruning. Folks will sometimes use Podocarpus or Ficus species that will grow to 50 feet or more if left unattended. A mixture of several different plant species can give you a bold effect by using variations in leaf and flower shape and color as well. For ideas on using the right hedge, you may call the UHCTAHR Master Gardener Helpline. In East Hawaii the number is (808) 981-5199, in West Hawaii, (808) 322-4893. There are also a number of local landscape architects and designers who can assist. Many nursery folks also have experience and can give you some tips. Many clumping bamboos make good hedges. You are in luck if you can check out the Quindembo Bamboo nursery sale coming up from 9 a.m. to 2 p.m. next Friday and Saturday, Sept. 22 and 23. Call or text Peter and Susan at (808) 987-6452 for directions. It is pleasant drive to their nursery in North Kohala. Fences also work but some are more attractive than others. Stone walls are traditional and impressive, but expensive. Today, we have so many choices that an unattractive fence or hedge might create all kinds of neighbor problems depending on type of material used. Screening on smaller-home-sized landscape may require fences to keep animals or children in bounds. However, chain link, concrete block and many other fence and wall materials do look kind of harsh and unsightly. They just don’t give that luxurious tropical feeling. So here’s where vines make ideal companions. Concrete and chain link make ideal supports for the many types of vine we have available like the red passion flower, jade vine, Kuhio vine, potato vine, creeping fig and many others. Vines serve many purposes for the gardener. Bird lovers like flame vine because they attract birds. Others like the privacy vines give them when sitting on the lanai. Many folks like vines because they harbor chameleons, anoles and geckos. Many song birds like vines because they are good nesting locations. And, last but not least, many vines are fine because of their attractiveness both in foliage and flowers. Vines lend contrast and character to landscape plantings. They can accentuate architectural lines, especially the closely clinging species. Many creepers are adept at introducing color, form and texture onto otherwise uninteresting objects, fences or even trees. Many gardeners say that vines are the best plants to give their homes an air of tropical living by using them to cover passageways or to form patio walls. Ornamental vines, as a group, are well adapted to a wide range of soils. Most of them thrive in sand, clay, or rocky land, provided plant food and moisture are adequate. Soil preparation is most important in a planting project whether you are planting a small shrub or large tree. Time spent improving the soil will ensure that you will produce vigorous plants and possibly have trouble-free care later. To get a project underway, spread about four inches of compost, peat, leaf mold, or well-decomposed manure over the area where the plants will be established. As a topping, sprinkle the area with fertilizer, and then mix the organic material and soil with a spade. The soil at the base of masonry construction often contains troublesome debris, so remove the contaminated soil to a depth of 18 inches. Replace it with good soil taken from another location. The planting season in Hawaii is any time the notion strikes you, provided the plants are healthy and container-grown. Bare root and transplanted specimens may need extra care in dryer locations. In planting, dig a hole that is larger than the root ball. If the plant is in a container, carefully remove the plant without disturbing the roots and settle it in the hole at the same depth it was in the container. Partially fill in around the plant with soil. Water thoroughly. Finish filling the hole and water again. There are hundreds of tropical screening hedge materials and vines available here on the Big Island. The Bengal clock vine, with its sky-blue flowers, the garlic vine, the exotic passion flower vines, confederate jasmine and philodendrons are just a few. Check with our local nurseries and get acquainted with what’s available. Norman Bezona is professor emeritus, University of Hawaii College of Tropical Agriculture and Human Resources.

For centuries even before we celebrated Dec. 25 as the day Jesus was born, earlier cultures celebrated the passing of the winter solstice in the Northern Hemisphere. The days will now get longer even though it is technically the beginning of winter and will last until the beginning of spring. Spring officially occurs when the sun reaches the equator as it appears to move northward. Of course what is actually happening is that the Earth is tilting toward the South Pole and will continue to do so until June 21. Then it is officially summer. Since we are roughly at latitude 19 degrees north, the sun will appear to move northward for a short time and then move toward the south until Dec. 21. Many plants respond to day length, including plants that form bulbs. At this season most mainland gardeners become bulb-conscious. Even in Hawaii, garden magazines and garden supply stores feature bulb, corm, tuber and pseudobulb advertisements as well as displays. An example of the latter are the thickened stems at the base of each growth like we see in the Chinese ground orchid, or Phaius tankervilliae. Gladiolus, cannas, gloxinias, tuberous begonias, callas, amaryllis and caladiums are just a few of the many types available. Although they vary in their requirements, there are several basic cultural factors to keep in mind. In general, most true bulbs grow best in a well-drained soil and a sunny location. The pH of the soil should run between 5.8 and 6.5. Most bulbs should be fertilized with a low nitrogen analysis fertilizer applied according to manufacturer’s directions on the label. If you keep these factors in mind, you should be able to produce excellent flowering plants. Energetic gardeners can have some bulb types in flower every month of the year. However, let’s concentrate on some early spring flowering bulbs we can plant now. Calla lilies can be started now and will flower during spring months. Incidentally, calla lilies are an exception to the cultural suggestions we have already mentioned. Callas will perform best in a soil that has considerable organic matter and is retentive of moisture, but not soggy. In order to obtain the best results, the clumps should be dug every three to four years and the rhizomes separated and replanted at a depth of 4 inches. Callas are at their best in cooler sections of the island like Volcano and Waimea, but they will grow in warmer sections as well. One of the most popular bulbs to try is the amaryllis. Amaryllis bulbs can be planted any time. Depending on the variety or hybrid grown, they will flower from now through May. The amaryllis is like most folks after the holidays. It must watch its diet. Too much food and the plant will not bloom, so it flourishes in poor soils like we tend to have in West Hawaii. Wild Amaryllis may even be seen growing along some of our roadways and around older homes up country. Here are a few tips to get your amaryllis to do their best. First of all, don’t tempt them with rich foods. Nitrogen-packed fertilizer makes the plant fat and green with few blooms. Like many other bulb plants, amaryllis bloom best when fed a miserly amount of a low nitrogen fertilizer. The idea is to starve the plant into worrying about next year’s blossom so that it will store food into a nice big bulb for the future blossoms, plus giving you a proud display of blooms this year. If the plants grow rampant on little or no food, try planting them in less fertile soil next time. Rationing water during the late growing stages will tend to produce better bulbs. Bulbs planted now will put on a flower show in 6 to 8 weeks. Select a fairly sunny spot for an amaryllis bed because too much shade will cause small flowers. Deep shade may cause the bulb to die. Colors to choose from are red, pink, white and a combination of these colors. If you can afford them, buy hybrid bulbs. With reasonable care they will give you bigger and better blooms. With fancy varieties, when the tops of the amaryllis die back in the fall, it is time to dig and divide the bulbs. Upon digging, remove the smaller offset bulbs from the mother bulb. It will take about three years for the juvenile bulblets to bloom, but in the meantime, the mother bulb will show her colors plus produce additional infants for future generations of flowers. Propagating bulbs by division is an interesting hobby. To try your luck, use a razor-sharp knife and a cut a large bulb into a number of pieces. You can separate it into 60 pieces if you have the knack of thin slicing. Be sure that each wedge of the bulb has a portion of the stem tissue attached to the scale portion. Next, dust the wedges with a garden fungicide to prevent diseases and plant them in a flat or bed containing a mixture of peat and sand or other porous medium. Keep the planting moist and humid and in about four weeks small bulbs will appear between the scales. The tiny bulbs are ready for potting. Three years later, you will have a bulb that will bloom. To propagate amaryllis by seed, harvest the seedpods soon after they turn yellow and begin to break open. Dry the seed pods a few days before sprinkling the seeds onto a flat of soil. Start the plants off in full shade, but gradually move them into full sunlight and then transplant them to a sunny spot in the garden. There are many other bulbs that can be planted at this time in Hawaii, including narcissus. You can also grow tulips here. Just store the bulbs at 40 degrees Fahrenheit for 60 days prior to planting and be sure to plant them immediately after removal from cold storage. Since tulips require cold weather, they have to

When the first Polynesians arrived in the Hawaiian Islands, there were very few plants that were of use as edible or medicinal. Initially they probably lived on what could be taken from the sea like limu, fish, vana, opihi, squid, octopus and sea slugs, just to mention a few. Of course, many birds flourished on the land. They and their eggs were fair game as well. Luckily the first people brought with them a great variety of plants like coconut, turmeric, sugar cane, ohe, kalo, mountain apple, breadfruit and scores of banana varieties. They also brought pigs, chickens, dogs and rats. The animals had a great impact on the ecosystem, since no land mammals except the Hawaiian hoary bat existed before the first people. Farming then was a necessity but as they became adapted to the new environment, they built a great society that lasted hundreds of years. Today, the cost of living is requiring a new approach to life in the islands. More folks may need to think of producing at least some of our food here rather than depending on imports. Farming for a living is tough. It is enough to drive you bananas, especially if you are a commercial banana grower in Hawaii. However, it is possible to supplement our food budget efficiently with easy to grow foods like bananas. Inflation gives us another reason to grow more of our own food rather than importing it. Many areas of our islands are ideally suited for producing good banana crops. The four secrets to success with bananas begin with the soil. Banana plants thrive best on good soils fairly rich in organic material. Plants prefer moist situations, provided the soil is well drained. They will grow in nearly any soil except one composed almost wholly of sand or rock. Bananas are seriously damaged by salt water and by high chloride accumulation in soils due to intrusion of brackish water in coastal areas. The second secret is wind. The leaves are likely to be damaged by strong winds Plants should not be planted in an exposed location. Tattered leaves cannot function as well as undamaged leaves. Third is that varieties are important. There are more than a thousand varieties of banana worldwide and more than 100 may be found here. Identification is not easy unless you really study. The best way to know your varieties is to obtain them from a reliable nursery. If you get keiki from a neighbor, make sure they are free of disease. Dwarf varieties like the Cavendish, or Chinese, is better adapted to small garden conditions as it has a short, stout stem from 4 to 7 feet tall, with broad leaves borne on short pedicles. It is somewhat hardier and more wind resistant than taller varieties. The fruit is of medium size, thin skinned, and of good quality. Growing larger to 20 feet, the Brazilian banana types are hardy and prolific. Williams hybrid is larger fruited variety, superior for home gardens and is grown commercially. Other less-known varieties with potential are Cuban red, dwarf Jamaican, and the thousand finger of Indonesia. A good resource book for identifying varieties is The World of Bananas in Hawaii by Angela Kay Kepler and Francis G. Rust. The book covers just about everything you ever wanted to know when it comes to this delicious and nutritious fruit. This and other books on gardening are a great way to improve your gardening expertise. Fourth is fertilization. Banana plants are heavy feeders and respond well to regular fertilization. Most Hawaiian soils are deficient in the major elements, nitrogen, phosphorus and potassium, and may be deficient in the elements magnesium, calcium, copper, manganese, boron and zinc. Bananas require all of them. As a general rule, bananas will thrive on the fertilizer mixtures shown by experience to be necessary on other crops grown on each particular soil type. The amounts required will also vary with the various soil types. Since bananas are heavy and constant feeders, results usually will be better from frequent light applications than from infrequent heavy applications. Mulches, compost and manures greatly benefit the plants as well. While the plants are young it is best to remove all suckers but one. This will force strength into the flowering stalk and leave one or two to take its place after fruiting. This way, larger bunches of fruit can be expected. Later, when the mat has matured, 3 to 5 stalks may be allowed to grow if well spaced. Bananas harvested 7 to 14 days before ripening and hung in a shady, cool place will develop their flavor and nutritive value better than if allowed to ripen on the plant. Bananas are hardy as far as pests are concerned. Occasional sprays of fungicides may be needed to keep leaves and fruit free of streaking or spotting fungus organisms. Be sure to read and follow manufacturers directions on the label. The main disease problem to avoid besides bunchy top is Panama wilt. Bluefield banana is susceptible as are several Hawaiian varieties. If these diseases are present, plant resistant varieties like Williams and Cavendish, since there is no economic cure for the diseases.

There are more than 1,200 species of bamboo that vary from a few inches tall like Sasa pygmea pygmea to giants like Dendrocalamus brandisii at 120 feet in height. There are runners that may spread if not contained, and others that form well-mannered clumps. Hawaii’s varied climates and cultural makeup are ideal for bamboo, but until the 1980s, there was no serious effort to introduce the valuable elite bamboos of Asia and the Americas. Thanks to the Hawaii Chapter of the American Bamboo Society and Quindembo Nursery, we now have many species from which to choose. Bamboos have been used in Chinese gardens since 2000 BC. In the later centuries leading up to AD 1000, the Japanese started trading with China, and many species were naturalized in Japan to enhance the gardens of temples and wealthy traders. The first recorded introduction to the West was black bamboo (Phyllostachys nigra) in 1827. In the 20th century, many species were introduced by USDA Experiment Stations in Puerto Rico and Louisiana with hopes to develop new crop potentials. From there, they were distributed throughout North and South America. Valuable bamboos species from Asia were established, tested and distributed throughout Central America and the Caribbean over the next few decades. Today, scores of species are utilized, but bamboo is not new to indigenous American cultures. Guadua species native to the Americas were used as early as 9,500 years ago. Asia is the ancestral home of many kamaaina, both people and plants. When it comes to plants, one of the most valuable is bamboo. Although there are many species found in Central and South America, tropical and subtropical Asia has utilized bamboo for thousands of years. It is said that bamboo and rice are the very foundation of these cultures. The Hawaiian ohe kahiko may be found in many parts of Polynesia. The actual genus and species is not clear with taxonomists, and botanists do not all agree. We do know that it is a tropical clumper probably originating in Southeast Asia. It is likely Schizostachyum and has been called S. glaucifolium in Hawaii. There are vast stands in the mountains of high islands like Raiatea in the Society Islands. Polynesians there still use it in crafts. With large tracts of land now available for forestry, and our local interest in sustainable agriculture, bamboo may become one of our major resources. It has many commercial and ornamental uses. Even though bamboos are excellent sources of edible shoots and construction material, most folks are interested in ornamental bamboos for their beauty. Bamboos, of one type or another, are a natural for almost any tropical garden. In fact, many of the hundreds of types grow in the tropics, but some species grow as far north as New York or Seattle, and can be found growing up to 10,000 feet in the mountains of Asia, Central and South America. The clumping bamboos are ideally suited for ornamental uses in their area of adaptation. They can be planted in groups for hedges or singly for specimen plantings. They spread very slowly and are easy to keep within bounds. One of the best for sunny locations is the Mexican weeping bamboo. Others to consider are the Bambusa multiplex forms such as Alphonse Karr, fern leaf, silver stripe and feather bamboo. These delicate clump types range from 10 to 20 feet in height. Other rare clumping types are beginning to show up in our nurseries like the Chusqueas and Buddha’s belly bamboo (Bambusa vulgaris wamin). For larger gardens, try Bambusa chungii (tropical blue) and weaver’s bamboo. There are several other bamboos also available. These are all clumping types in the 20 to 40 foot high range with fancy Latin names and multiple uses. The giant tropical clumping bamboos need plenty of room since they soar from 50 to over 100 feet tall under ideal conditions. This group includes the larger Bambusa, Dendrocalamus, Guadua and Gigantochloa species that may have culms six to 12 inches in diameter. They are grown for edible shoots, construction material, windbreaks and furniture. Favorites are the black culm types like hitam, lako and Gigantochloa atroviolecea. Another favorite spectacular giant is Dendrocalamus brandisii. Bamboos do best in a moist well-drained soil with some organic matter. Apply complete fertilizer, such as organic 8-8-8 or manures, four to six times a year to the planting. Mulch the soil around the planting. Mulches add organic matter to the soil, help to restrict the growth of weeds and conserve soil moisture. Dead leaves or dry grass clippings can be used for mulch. Apply a layer of mulching material at least three inches deep. For further information on bamboo, call the UHCTAHR Master Gardeners at 322-4893 in Kona or 981-5199 in Hilo. You may also contact Quindembo Nursery in North Kohala by checking out their website. Norman Bezona is professor emeritus, University of Hawaii College of Tropical Agriculture and Human Resources.

We frequently talk of protecting the rainforests and cloud forests of Hawaii, but often neglect the importance of Hawaii’s dry land forests. However, thanks to the efforts of Ka‘ahahui o Ka Nahelehele we are beginning to understand the importance as well. According to Mary Metcalf, president of the nonprofit organization, its mission is to advocate the perpetuation of Hawaii’s dry forest ecosystems. This year they are presenting the 14th annual Nahelehele Dryland Forest Symposium from 8:30 a.m. to 4:30 p.m. on Friday, Nov. 17 at King Kamehameha Kona Beach Hotel. It is important to register early this coming week since space is limited. There will also be a field trip to the Palamanui Community Forest Preserve on Saturday, Nov. 18. Changing climate, invasive grasses, fires and grazing by goats, sheep and cattle have placed these forests and indigenous wildlife at risk. The symposium features presentations by Hawaiian cultural experts, scientists, restoration managers and landowners engaged in stewardship and research to preserve dry forest ecosystems. Preserving dry land forests is very complicated in that invasive grasses are more successful in colonizing drier areas than are native species. Where there is sufficient rainfall, trees like koa are able to shade out grasses. Low precipitation regions like Waikoloa and coastal West Hawaii where rainfall is a few inches per year are a real challenge. Also, regions that were once heavily forested have become grasslands due to climate change and human activity. Speakers will address these issues. For further information call Mary Metcalf at (808) 238-4871 or go to info@drylandforest.org. Take a drive over the mountains to East Hawaii and you will note much of the island is stark and appears to be barren, but on closer observation many rare birds and plants are to be found. In stark contrast you may visit West Hawaii’s cloud forests that are easily accessed via Kaloko Dr. from Mamalahoa Hwy. Just 15 minutes from the airport, the drive starts at 1,500 feet. In 10 minutes you can find your way up Mt. Hualalai to 5,000 feet elevation. This region is still covered with native forest and easily accessible in 15 minutes from Kailua-Kona. Although it is sparsely populated, the gardens of residents are a fascinating mixture of hoawa, koa and kopiko. The area abounds with ancient ohia (Meterosideros polymorpha) and gigantic treeferns. These ferns may be hundreds of years old. The native forests contain many rare and endangered species that local residents are committed to protect through the Hawaii Forest Stewardship Program. This program allows residents to dedicate and manage their properties to enhance this important and unique cloud forest watershed. It is administered through the Hawaii Department of Land and Natural Resources Forestry Division. Kaloko Mauka is the home of the Hawaiian hawk, apapane, iiwi, elepaio, amakihi and many other endemic and exotic birds. The last few wild Hawaiian crows were seen in the area. Kaloko Mauka has been identified as essential wildlife habitat and forest watershed. It is the goal of residents of Kaloko Mauka to set an example that they can live in harmony with the forest and still have homes and some forest friendly agriculture activities. This is essential if our island is to have the rainfall and watershed needed to supply communities at lower elevations. Some folks feel that East Hawaii has plenty of rain, so forests are not necessary. However, forests are like big sponges. They slow down flooding rains, and give up moisture so that streams continue to run when rainfall is light. Without forests, flooding and drought as well as severe erosion becomes the norm. Also, grassy areas are notorious fire hazards during times of drought. Tropical forests worldwide include not only trees but understory palms, bromeliads, orchids, ferns and bamboos. Many palms worldwide are endangered due to the destruction of rainforests. Fortunately, Hawaii is becoming a kind of Noah’s Ark thanks to the efforts of the Hawaii Island Palm Society, Hawaii Island Landscape Association, Bamboo Society, Sierra Club and other concerned groups. Not only is it vital to protect our remaining dry land, cloud and rain forests, but to reforest those abandoned cane lands of Hamakua, Puna, Kau and Kohala with biodiverse forests thus ensuring valuable resources for future generations. For further information contact konacloudforest.com

It is time to think about planting your fall vegetable garden. This week and for the next few weeks let’s consider landscapes that feed us. You might even want to take the organic approach. Since our soils have lost many nutrients let’s look at the best sources to consider. Where animal manures are available, they are probably the best sources of nutrients for the organic gardener. After planting, using cow, horse or hog manure, side dress with up to five pounds per 100 square feet. When applying a side dress, scatter the manure at the edge of the root zone and work lightly into the soil surface. If mulch is present, rake it back at the edge of the root zone in order to apply the manure, then recover with the mulch. Remember, manure is not always a complete balanced fertilizer. It is advantageous to broadcast a complete fertilizer such as organic 8-8-8 plus trace elements or ground rock phosphate and potash in addition to the manures. Compost is an alternative to animal manure; it should be applied as you would manure. Broadcast it over the entire vegetable garden area three weeks or more before planting. Or if you have only a small quantity of compost, it may be mixed into the soil. In all cases, apply it at the rate of about 25 pounds per 100 square feet. Natural and organic materials that yield plant nutrients upon decomposition are often available for purchase either separately or in combination. These materials may be applied separately or combined, used in the compost pile or mixed with manure. Many of the more commonly available materials include both the organic materials derived from plants and animals, plus the natural deposits of rocks and minerals. Such naturally-occurring materials are usually not easily obtained in today’s modern agriculture. However, where available, they are sources of mainly potash, phosphorus and lime (calcium and magnesium) for organic gardeners. Rock phosphates are natural deposits of phosphate in combination with calcium. Rock phosphate yields its phosphorous very slowly. When finely ground and with impurities removed, the powdery material is only slightly soluble in water, but may be beneficial to plants in subsequent seasons following application. The reaction of phosphate rock with acids from decaying organic matter in the garden or compost tend to make the phosphorus more readily available to plants. If the soil is alkaline, phosphorus may not be available. Apply ground rock phosphate at the rate of two to three pounds per 100 square feet of garden soil or, when applying manure or compost, mix a the rate of 2-1/2 pounds phosphate per 25 pounds of manure or compost. Broadcast the material over the soil surface and work into the topsoil at least three weeks before planting. Manure or other organic fertilizer should be added at this time. Since the rock phosphates are so slowly decomposed, side dressings are seldom beneficial. Potash or potassium is widely distributed in nature, occurring in rocks, soils, and the tissues of plants and animals. In gardening practice, materials such as wood ashes, banana skins, seaweed, potash salts and ground rock potash are used alone, in combination with other materials yielding other nutrients, and mixed with manure or in compost piles. Since the potash-bearing materials vary so much in composition and rate of decomposition, specific application rates must be determined for each material and its combination. An advantage for using organic materials as fertilizers is that they contain many of the elements also needed by the plants such as zinc and iron. Reducing the acidity of the soil is the primary purpose for using lime in the garden. However, liming materials also provide nutrients for plant use. Calcium and magnesium are the two elements most commonly provided by dolomitic lime. Natural deposits of lime that an organic gardener might use are crushed coral, dolomite and shell. All these forms must be finely ground to provide maximum benefit to the soil and plants. Lime to sweeten the soil should be applied only when the needs have been established by a reliable soil test. Under most soil conditions, application of two to three pounds of finely ground dolomitic limestone per 100 square feet usually will be sufficient except on very acid soils. Apply lime well in advance of the planting date, preferably two to three months before the garden is planted. Mix well with the soil and keep moist for best reaction. If all this sounds complicated, don’t be discouraged. Not everyone is a soils chemist! There are some great books at local garden shops that will help. Also, the University of Hawaii College of Tropical Agriculture and Human Resources Master Gardeners are available to assist. You may call 322-4893 in Kona or 981-5199 in Hilo. Norman Bezona is professor emeritus, University of Hawaii College of Tropical Agriculture and Human Resources.