Monday, April 1, 2019

Plant a Rainbow of Colors in Your Garden


When planting a vegetable garden, let color be your guide to healthy eating.  For a number of years, scientists have been discovering the health benefits of the color pigments in food.  For some gardeners, a vegetable garden is lettuce, collard, mustard greens and kale- all healthy, leafy green vegetables.   But for health sake, add some color such as red tomatoes, yellow squash and purple eggplant.  Grow a rainbow of colors to the garden for good health.

Red colored fruits and vegetables contain natural plant pigments called lycopenes or anthocyanins. These compounds may help reduce the risk of several types of cancer, especially prostate cancer. By the way, the lycopenes in cooked tomatoes with a small amount of fat are absorbed better than lycopene from raw tomatoes.  Sun dried tomatoes are reported to have twelve times the lycopenes as raw ones. So plant plenty of tomatoes, beets, watermelon and red peppers. If there is room in the garden, include a pigmented citrus tree like pink grapefruit. 

Orange and yellow colors come from natural plant pigments called carotenoids.  Beta-carotene is converted to vitamin A which helps maintain healthy eyes.  Carotenoid-rich foods can reduce the risk of cancer, heart disease and improve the immune system function.  Plant plenty of yellow sweet potatoes, squash, pumpkins and carrots.  Citrus contains hesperidin, also found in the skin of tomatoes, and naringenin, which are anti-inflammatory and antioxidant. Curcumin, found in turmeric, known in Hawaiian as olena, has antioxidant properties. Turmeric is a popular Indian spice used in curries and other dishes.  Anecdotal evidence suggests that turmeric can be used to deter ants in the garden.

Other yellow and orange fruits grown in Hawai`i are pineapples, papayas and mangos. Pineapples contain bromelain, an enzyme which aids digestion.  Papaya and tangerines contain beta-cryptoxanthin, another carotenoid, playing an important role in vision and in bone growth. Papayas can easily be grown from seeds or purchased in abundance at local markets.

 Greens are colored by a natural plant pigment called chlorophyll.  Some greens contain lutein which helps keep eyes healthy. Here is a familiar list of green vegetables: green peppers, peas, parsley, watercress, arugula, spinach and kale.  Crucifers like broccoli and cabbage contain chemicals which may help protect against some types of cancer.  Leafy greens such as spinach and broccoli are excellent sources of folate, which is a B vitamin. 

The blue and purple colored fruits and vegetables also contain pigments called anthocyanins, powerful anti-oxidants which improve brain function and help to reduce the risk of cancer, stroke and heart disease.  Fig trees grow well in tropical and sub-tropical climates and should yield delicious, healthy fruit.  Anthocyanins, also found in strawberries and raspberries, act as powerful antioxidants that protect cells from damage. 

The whites contain pigments called anthoxanthins which are shades of white or yellow.   This group consists of onions, garlic, cauliflower, turnips, mushrooms, potatoes and bananas.  At least one of the group, garlic, contains a health-promoting chemical called allicin. This compound may help lower cholesterol and blood pressure and help reduce the risk of stomach cancer and heart disease. Potatoes, as well as bananas, are good sources of potassium. 


Sunday, March 3, 2019

Medicinal Teas of Hawaii: Mamaki and Ko’oko’olau



Mamaki (Pipturus albidus)  is a Hawaiian endemic plant occurring on all the main Hawaiian Islands except Ni'ihau and Kaho'olawe. It grows in moist to wet forests at elevations ranging from close to sea level to 6,000 feet. It can be considered a shrub or a small tree ranging in height from 6 to 20 feet tall.

Dried or fresh mamaki leaves are used to make a tea often drunk by those feeling lethargic. The tea is also used to help with many internal disorders such as for the stomach, colon, bladder, liver, and bowels.  The fruit is eaten as a laxative or for stomach, colon and digestive problems. Infused leaves can be used in treatment for high blood pressure, high cholesterol, liver problems, and bladder problems.  In some people mamaki can cause mild agitation or insomnia.





Mamaki is the primary food source for caterpillars of the native Kamehameha butterfly. Planting this shrub in the garden will provide food for the butterfly as well as a healthy, invigorating tea for the gardener.

Mamaki is a highly variable plant. The leaves are dark-green on the top and white to gray underneath. Some varieties have reddish veins.  It is generally not suited for hot, dry coastal settings, but will grow well in urban landscapes with some shading. It will also do well planted in containers in part shade. The red-veined varieties appear to tolerate full sun better than green-leaved varieties. The mature plant recovers after pruning if no more than one-third is removed.

Mamake plants are usually propagated from seed. The fruit can be ripened in a plastic bag to soften the pulp.  Seeds are then removed from the pulp by rubbing the fruits in a strainer under running water. The viable seeds will sink and the fruit pulp and other debris can be poured off. Seeds then need to be dried on a paper towel and stored. Once planted, seedlings will thrive in a well-draining soil in a semi-shaded to shaded location.  The plants can also be propagated from cuttings.   


Ko’oko’olau Bidens menziesii is in the sunflower or aster family.  It can be an annual or perennial shrub, ranging from 3 to 12 feet in height, growing in a wide range of habitats. The plant is found on Molokai and West Maui and on the leeward slopes of Mauna Loa and Mauna Kea on the Big Island.  It is easy to grow, preferring full sun and light to moderate watering. It grows well as a potted patio plant.

Ko’oko’olau was widely used by Hawaiians prior to European arrival. Its leaves were used as a revitalizing tea. Flowers were used to stimulate appetite. Today the tea is still sold; however, Bidens pilosa is often the species incorrectly labeled and sold as the traditional Hawaiian tea. 

Saturday, February 2, 2019

Bugs - the Good, the Bad and the Ugly



Not all bugs in the garden are bad. 
Some bugs are beneficial. such as parasites and predators. The are looking for pests to consume. Two well-known good guys are preying mantis and lady bird beetles; spiders are also good predators.  Biological control can work very well. As an example, in California when certain species of whitefly came into a new area, both citrus  and some vegetable crops were damaged or completely destroyed. Yet within a number of years, their natural enemies were established, and for the most part, the pest became inconsequential.  Pollinating insect can also be categorized as beneficial.

Some bugs may be found on a plant, but are not feeding and therefore cause no damage. The bug may simply be resting or perhaps searching for nectar or another source of food.                                                                                                   
               
Some insects of course are known pests, but cause little damage. A bite may be taken from a leaf here and there,  or a little juice sucked from a stem, but overall, the plant is not harmed. 
On the other hand, some bugs do inflict damage, but it is only cosmetic. That is, the leaves or fruit may be scared or misshapen, but there is no real loss of yield.  In many cases, cosmetic damage should be tolerated. This type of damage on citrus fruit is caused by thrips and does not affect the internal quality.    
Above Photos: University of California IPM Program

And finally, if there is an infestation of an insect pest which will cause yields to be significantly lowered, the gardener will have to decide whether to wait a bit and see if biological control will work. If a parasite or predator can control the pest population, no intervention is needed. Yet if spraying is the choice, consider first a bio-rational pesticide, such as soap, oil, Bt or sulfur. These are less injurious to the environment, and may not harm the predator or parasite populations. 

And, the Ugly
Colorized image of a flower beetle
Arizona State University