Tuesday | April 21, 2015
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Is it better to plant beneath a new moon?

Recently, I heard two separate people mention transplanting on the full moon and planting on the new moon. Is there any scientific truth to this? What can you tell us about gardening with the moon cycles? — Mahalo, L.

Planting by the moon is a belief system that has been around since ancient times. Yet there are very few scientific articles which discuss this issue. Many nonscientific articles can be found claiming a lunar effect on plants, and also many papers discounting any effect. An abundance of evidence has been presented to support lunar plantings, but it does not stand up to close scrutiny, i.e., improperly conducted experiments and a failure to account for variables and bias. Many of the references used as evidence for lunar effects on plants are vague; they have not been reviewed by the scientific community, but rather consist of self-published books and lectures. There are some legitimate papers which indirectly link lunar cycles with plant biochemistry. We cannot dismiss some lunar effects on plants entirely. But such effects must be consistently demonstrated under controlled conditions. Until then, planting by the moon cannot be considered a science-based practice. In other words, a long-term scientific study which supports lunar planting has yet to be produced.

My question is why have my last two pineapples refuse to grow or ripen? I’ve already harvested about eight pineapples, but the last two have been sitting on the mother plant since May. They’re little bigger than softball size and green as ever. I remember last year the last pineapple did the same; it didn’t grow or ripen and I ended up picking it and throwing it away. — Mahalo, Rod

There are a number of reasons why fruit will not reach maturity. Most of them have to do with poor health of the plant. In your case, however, the reason could be the weather, not enough sunlight, and therefore, not enough heat to bring the fruit to maturity. If the fruit were left on the plant, and barring any pest infestation, they would have eventually ripened.

Poor health in pineapple plants and a lot of other plants can also be caused by nematodes, root rotting fungi and/or heavy infestations of insects such as scale and mealybugs.

Water and fertilizer need to be adequately supplied for proper health; pineapple in particular needs nitrogen, potassium and iron.

Small fruit sizes in pineapple are a common phenomenon of the ratoon (second crop). They are also seen in neglected plants and those exposed to prolonged drought — not the problem in Hilo. In addition to correcting the above pestilence, removing developing slips and suckers will enhance the rate of growth of pineapple plants and reduce the time it takes them to become large enough to induce flowering and produce large fruit.

What are micro and macro


A total of 17 nutrient elements are known to be essential for plant growth and development. Three are taken from the air — carbon, hydrogen and oxygen. Micronutrients are those essential elements that are required by plants in very small quantities.

They are boron, chlorine, copper iron, manganese, molybdenum, nickel and zinc.

The macros are those elements required by plants in relatively large amounts. They include nitrogen, potassium, phosphorus, calcium, magnesium and sulfur. All fertilizer packages will display three numbers on their label. These numbers specify the percentage of nitrogen, phosphorus and potassium (in that order N-P-K) in that fertilizer. (K is used for potassium, coming from the Latin kalium)

Reminder: I am teaching a citrus class from 9:30 a.m.-12 p.m. on Nov. 3 at the University of Hawaii at Hilo UCB 118. There is a fee.

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 askthegardenguy@earthlink.net.


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