Many plants that we grow for food can also be used in healing remedies. If you choose carefully, your edible garden can double as a natural first aid kit.
Culinary ginger root (Zingiber officinale) adds flavor to many dishes. This root crop can also be used to make a tea to calm an upset stomach or can be chewed raw to alleviate nausea from sea sickness. Mint or Mysore raspberry leaves can be added to help soothe the stomach, and fennel leaves can help with gas. All of these plants have uses in cooking as well as in treating minor ailments.
Aloe vera is a must for every gardener who cooks. It can even be grown in a container in or near your kitchen if you frequently burn your fingers. This succulent plant produces long fleshy leaves that are full of a clear gel that soothes burns, sunburns, bug bites and any wounds or irritation on your skin. The gel is also an ingredient in some natural stomach soothing remedies.
Comfrey (Symphytum officinale) is another must have for a healing garden. Its best uses are as an external healer. The plant component allantoin is found in comfrey and encourages growth and repair of connective tissue, skin and bones. Known commonly as “knitbone,” a poultice of comfrey leaves compressed to broken bones, sprains, bruises or shallow wounds will help them heal quickly.
Stevia leaves (Stevia rebaudiana) are grown as a natural sweetener, but can also be made into a tea to heal scalp and hair problems. Left on your head for five minutes before rinsing, stevia tea can heal dandruff and help prevent hair loss. Add rosemary leaves to stimulate hair growth, add shine and a pleasant scent.
A rosemary (Rosmarinus officinalis) concentrate can be made for dandruff treatment. Bring a cup of apple cider vinegar to a boil, pour it over about 4 tablespoons of chopped rosemary leaves and let it sit overnight. Use about 1/8 cup of the concentrate in 1 cup of water for the hair rinse. You can also let the rosemary sit in the vinegar for a few weeks and strain for a flavorful vinegar for salad dressings.
Cayenne peppers are another edible plant that can serve double-duty as a healer. Adding just a little hot pepper to a recipe definitely enlivens the flavor. Known botanically as a cultivar of Capsicum annuum, cayenne peppers contain capsicum, which is the active ingredient for healing. Taken internally, hot peppers can encourage circulation and increase digestive secretions. Applying the cut fruit to a wound can stop bleeding as it has styptic properties as well. However, it will also burn so use only in emergencies. Consuming capsicum will increase sweating and can be used to break a fever.
These are just a few of the healing plants we can grow here. More will be covered in future columns. To capture and save the healing properties of these plants you can make tinctures or oil infusions that have a longer shelf life and can be used on trips as well as at home when needed.
Making an alcohol-based tincture involves cutting up fresh or dried leaves, roots or fruit and filling a clean glass jar about ¾ full with the plant material. Cover the material with 80- to 90-proof vodka and shake vigorously to get all of the cut surfaces exposed to the alcohol. Allow the extraction to occur over 6 to 8 weeks, shaking the jar at least weekly and checking to be sure the jar remains full of alcohol. Once the extraction is complete, strain the liquid through muslin or several layers of cheesecloth into a colored glass bottle and squeeze the herbs in the cloth until dry. Be sure to label your bottle with the date and the name of the plant tincture, as well as its uses.
An oil infusion can also preserve a plant’s healing properties. Start with a clean, dry jar and cut up clean and dry plant material to fill the jar. Next pour warmed oil (olive or grapeseed works well) over the herbs. Place the jar in a warm or sunny spot for a few weeks then strain the oil removing the plant material. Again, labeling your infusion immediately can save you later guesswork.
Get started now with a few healing plants and continue adding as you learn more healing properties of plants we can grow easily here in Hawaii.
Tropical gardening helpline
Joy asks: I’m having problems with my citrus trees. Some leaves have large dark brown areas. The leaves on my orange tree are kind of crinkly and curled and the back of the leaves on my lemon and lime have strange lines and grey spots. Help!
Answer: Citrus trees usually grow well in hot, dry areas as long as they have adequate sun and water and are in healthy soil that drains well. The trees need six hours of full sun to thrive. Fertilizing with a good citrus fertilizer once or twice a year can help avoid nutrient deficiencies. If conditions are optimal, problems should be minimal.
It does sound like you are having some problems, however. Try to correct the less than optimal growing conditions and your problems will likely decrease. Meanwhile, several easy remedies may help with your current issues.
The dark brown areas on the leaves do not appear to be caused by an insect or a disease. Perhaps something is dropping on the leaves from a roof overhang, something has been spilled on them or something has burned them. The problem seems to be caused by an external event.
That curling or crinkling of the leaf is most likely caused by the broad mite. These mites usually feed on new leaves but can also attack the fruit, eating the rind causing a bronzing or dulling of the skin. Neither damage is threatening to your tree. It is mostly cosmetic.
If you want to spray with soap and oil, you may discourage the mites that are likely causing the leaf crinkling. Safer soap and neem oil should do the trick. Mites are usually attracted to flushes of new growth, which often appear in the spring or just after fertilizing with nitrogen. Cut back on the nitrogen a bit if you find your tree putting out lots of succulent new growth.
The bronze trail on the back of your leaves is caused by the larvae of the leaf miner. The adult lays her eggs on the host plant. The larvae emerge and feed on the tissue between the upper and lower leaf surfaces then drop to the ground to pupate into an adult. The cycle continues in two-week intervals. Though leaf miners will not usually kill a plant, interruption of this cycle at any point will help to reduce the infestation. If damage becomes severe you can place plastic sheets under the trees to catch the pupating larvae or you may want to prevent the adults from laying eggs by spraying a low toxicity insecticide, like one containing neem, to kill the adult.
The gray spot on your leaves appears to be a small colony of aphids. You can nip this in the bud by killing these small colonies with safer soap and neem or a pyrethrum insecticide. Both are low toxicity. Aphids are often farmed by ants, so reducing ant traffic on your trees with sticky barriers or ant traps can help reduce aphid populations.
Though none of your issues seem life-threatening to your plants at this point, dealing with them quickly will help your plants remain in good health. Improving the growing conditions and avoiding overwatering or overfertilizing can help your plants become less susceptible to insects and diseases. Try to give your plants just the amount of water and nutrition they need to prevent a miner attack.
For more information on growing citrus in Hawaii you might want to check out the CTAHAR publication “Citrus for Hawaii’s Yards and Gardens”, which can be downloaded at ctarh.hawaii.edu/oc/freepubs/pdf/F_N-14.pdf .
Email plant questions to email@example.com for answers by certified master gardeners. Some questions will be chosen for inclusion in this column.
Diana Duff is a local organic farmer as well as a plant adviser and consultant.