Monday, January 26, 2015

Pets and Poisonous Plants





Time and again, dogs and cats are rushed to the veterinarian's office after ingesting a poisonous plant. We can't always keep our pets 100% safe, but it is certainly worthwhile to know the plants which are the worst offenders and then, keep them out of the yard!

Many common garden plants that are toxic to dogs, cats and other animals. Some are more potent than others, and it often depends on how much is ingested. Symptoms can range from irritation of the mouth to lethargy, vomiting, diarrhea, convulsions and even death.

Here is a list of some of the more common toxic plants: Azaleas and rhododendrons, cycads, cyclamen, daylily, foxglove, heavenly bamboo, lily, and Yews. 

For a more comprehensive list and more information, go to the ASPCA’s Poison Control Center at www.ASPCA.org

Attention Big Island Residents: I will be teaching a class, Vegetables in the Home Garden, on Saturday, February 21, 9:30AM -12:30PM at UH-Hilo Campus. Call 974-7664 to register; there is a fee.

Monday, January 19, 2015

Is It Cilantro Or Is It Coriander?





Most chefs are familiar with the seasoning coriander. Coriander is actually the small, dried fruit, often referred to as the seeds of the cilantro plant. In fact, the scientific name for cilantro is coriandrum sativum, or coriander, also known as Chinese parsley. The fresh leaves and the small dried fruit are the parts most traditionally used in cooking.

The fresh leaves are often used in South Asian and Chinese cooking as well as in Mexican cooking, particularly in salsa and guacamole.  Since heat will diminish the flavor, leaves are frequently used raw or added just before serving. The leaves lose their aroma when dried or frozen.

Coriander seed is a main ingredient in garam masala, an Indian spice, and in curries. Although the ingredients in garam masala can vary, it commonly includes coriander, black pepper, cumin, cardamom and cinnamon.  In India, roasted coriander seeds, called dhana dal, are eaten as a snack.

Coriander is used for pickling vegetables and for making sausages in Germany and South Africa. In Russia and Central Europe, the seeds are used as an alternative to caraway seeds. Even in brewing certain types of beer, particularly some Belgian wheat beers, coriander is an added flavor.

The Problem of Bolting


Cilantro is a cool season plant. It flourishes during cool nights and moderate, sunny days as in the spring and fall. But it will bolt at the first sign of hot weather. Bolting is the premature flower formation initiated by hormones within the plant system in response to high temperatures, as well as drought and starvation.  This unwelcome occurrence in leafy vegetables such as cabbage, lettuce and cilantro, takes the plant out of its leaf producing mode and switches over to flower and seed production.  

On the Big Island of Hawaii, the Volcano and other similar areas would perhaps give cilantro the longest season, provided there is adequate sunshine. Cilantro, however, is a true annual and even under the best conditions, it will send up flowers and eventually die within the year. In order to minimize the bolting effect, cilantro should not be grown during the warmer, summer months. The best time for planting would be after the summer heat from September or October until perhaps March.

There are some slow-bolting varieties, Calypso is one, that can extend cilantro’s productivity perhaps a month. Snipping off the first newly emerging flower buds may also extend the leafy period, but only slightly. 
 
Like many plants, coriander may contain properties useful in the treatment of Type 2 diabetes and high cholesterol.  Research is presently investigating these claims and other medicinal attributes of coriander.  

Monday, January 12, 2015

Black Sooty Mold





What is the black, sticky substance that may be found covering the leaves of many plants?

The black substance on the leaves is called sooty mold.  It is a fungus which resembles soot. This particular fungus, however, is not harmful to the plant but is actually living on a sweet, sugary substance called honeydew.  The honeydew is being secreted by some insect that is infesting the plant. If you see sooty mold on a plant, it means that the plant has an insect infestation – most likely aphids, mealy bugs, soft scale or whitefly. 


As the insect feeds, a clear sugary liquid is secreted by the insect onto the leaf below.  It is on this secretion that the mold grows.  Heavy rains will wash off the sooty mold from the leaves, but the insect problem still needs attention. Often when large trees become heavily infested with certain insects, the honeydew can actually be seen raining down upon the ground.  Again, sooty mold indicates an insect problem. 

Monday, January 5, 2015

Cacoa, Macadamia Nut and Coffee Trees - Climate Limitations





The cacao tree evolved as an understory shade tree in tropical rainforest areas. For commercial production, cacao is best adapted for hot, humid tropical areas with evenly distributed rainfall. This would mean year-round temperatures at, or above 68°F and no freezing temperatures.

For individual trees around the home, these limitations can be stretched.
Optimum temperatures range from 65 to 90°F. Temperatures below 50°F may damage or kill the plant; defoliation and dieback will occur between 40-46°F.  Most importantly, flowering and thus fruiting only occurs when temperatures are at or above 68°F. Temperatures in excess of 90°F  may also limit plant growth. As a reference the warm subtropical climate in South Florida is very marginal for growing cacao.

Cacao is a shade plant and grows best with about 25% shade.  It is often planted with other commercial crops that protect it. In some regions it is grown in full sun, although shade is used during establishment.  For homeowners it can be planted under the canopies of tall overhanging trees or next to buildings or structures. Cacao does not tolerate windy conditions and should be planted only in wind-protected areas.



On the other hand, macadamia nut trees can withstand colder temperatures than cacao. Although they are adapted to warm, subtropical conditions, mature trees can withstand winter temperatures as low as 25-26°F for short periods with minor foliar damage. Young trees, however, are killed by temperatures near freezing. Temperatures below 28°F will cause damage to flowers and young fruit thus reducing production. In the tropics, macadamias are better adapted to medium elevations of 2100 to 3600 feet.  In Hawaii, commercial macadamia trees are not planted above 2500 feet.



                                                                                        Forest and Kim Starr
The optimum growing conditions for coffee include high humidity, protection from wind and temperatures from 59 to 75°F. Coffee plants are damaged or killed by freezing temperatures, while constant temperatures at or below 41°F may cause leaf drop and tree decline.

In the tropics or the warm subtropics, coffee is grown at high altitudes up to 3,500 feet; temperatures there are moderate and never freezing. In a few places in Kenya and Columbia, coffee is grown at elevations as high as 7,000 ft.