Aloha, Nick. Thank you for your column. Your knowledge is greatly appreciated! My question is in regards to one of my citrus trees. I think it is an orange but could be a tangelo. The fruit, whether young or ripe, does not have any juice inside. They are extremely dry and puckered from the outside. Do you know what causes this and if I can correct it?
There are a number of reasons for dryness in citrus fruit. Since we have had this question before, I will not go into detail. You can check my website for a complete discussion on dry citrus fruit, www.gardenguyhawaii.com.
In brief, overly mature fruit is a major cause of dryness in citrus. In other words, if the fruit is left on the tree too long, drying occurs. Certain varieties of citrus, especially mandarins, seem to be more susceptible to producing dry fruit. A further thought is that your citrus tree is most likely a tangelo, rather than an orange since its fruit is more prone to dryness. Tangelos are hybrids, produced by crossing a mandarin with either a grapefruit or pummelo.
There are a number of different varieties of tangelo, one in particular that was discovered in Jamacia, is called the Ugli fruit. In your case, if fruit is truly young and still dry, I would have to conclude that the tangelo is not the citrus for your area.
Hey Garden Guy, last spring, my neighbor had her avocado tree trimmed, and a plumeria tree removed and shredded. The company gave me the mulch at no charge. I am starting a backyard garden in Manoa, and I was wondering if it would be okay to use the mulch in between my garden rows? Thanks, Eric
Absolutely. The mulch will immediately provide weed control, and organic matter and nutrients as it breaks down. It will also help in conserving water which is important during periods of drought.
In addition to using the material as mulch, you can combine some of it with green garden waste. Leafy green material in equal proportion to brown woody material will help create a healthy compost pile. If you have large amounts, place the mulch over an area in the garden and let it set for a year of more. This will then become a new garden area ready for planting.
There is one caution: do not use the fresh mulch as an amendment. This means mixing large quantities into the soil and then immediately planting young trees or seedlings. As wood breaks down, ammonia is produced. In high concentrates it is toxic to roots. Planting young seedlings with small root systems into this environment can cause serious injury to the plant. If large amounts of wood products are incorporated into the soil, it would be a good precaution to wait several months for much of the wood to decompose.
Another caution: wood is decomposed by microbial action. During the decomposition period, bacteria and other microorganisms utilize nitrogen from the soil. This will cause a temporary nitrogen deficiency, which means the nitrogen is not available to the plants. Young plants growing in this situation may experience a temporary yellowing. A simple solution is to scatter a high nitrogen fertilizer over the wood before mixing into the soil. The fertilizer can also be applied after incorporating mulch into the soil.
I will be teaching a vegetable gardening class from 9:30 a.m.-12 p.m. on Saturday, April 20, at the University of Hawaii at Hilo. Call 974-7664 to register, or go online at http://hilo.hawaii.edu/academics/ccecs/fitness/.
Hilo resident Nick Sakovich is a professor emeritus of the University of California. He has worked in the field of agriculture for 30 years. Email your questions to Sakovich at email@example.com.