Manure ‘Tea’ All The Rage For Plant Life

This will be the last in a series of four articles on organic gardening. Today we look at fertilizers and natural pesticides.

Fertilizers: Whether fertilizers are sold as natural or synthetic, by law, all packages must indicate the amount by percentage of the three major nutrients: nitrogen (N), phosphorous (P) and potassium or potash (K). Most natural or organic fertilizers are released slowly to the plants while adding to and controlling the chemical, physical and biological properties of the soil. A few of these fertilizers are fish meal (liquid or pelleted), bone meal, blood meal, cottonseed meal, seaweed, rock potash and wood ashes.

Animal manures, other than cat, dog and pig, are also excellent additives to the soil when they’re well-rotted. Some manures are higher in NPK then others. Horse, cow, goat and sheep are the lowest. Rabbit, chicken and bat are the highest. Before using manure from horses or cows, check with the owners to make sure herbicides were not used on the pastures.

Manure teas are the “in” drink for plants. They are excellent liquid fertilizers. You may wish to try this simple recipe. Fill a drum or large bucket with water and set it in the sun. Collect a sack full of manure - gunny sack or cheesecloth will do. Tie the top of the sack closed with a thin rope or twine and tie the rope to a wooden dowel. Rest the dowel on either side of the bucket and drop the sack into the water. When the water turns brown, you know you’ve brewed a delicious tea for your hungry plants. If the water starts looking a little too dark over time, dilute it with more water.

Natural pesticides: Are they really safe?

There are two ways of looking at safe: Safe for the environment and safe for humans. According to Cheryl Best, former urban horticulture specialist with Cornell Cooperative Extension, all carbon compounds, including lab-synthesized pesticides, are classified as organic. Natural pesticides, on the other hand, include only those products extracted from natural sources like plants. This is still no guarantee of safety. Many of the most poisonous chemicals known occur naturally.

Most natural pesticides do less ecological damage than synthetics because they break down rapidly when they are exposed to light, heat and water. But how do they affect humans?

Nicotine can be very poisonous to the human nervous system. It’s also toxic to birds, fish and other mammals. Along with killing off a number of different, harmful insects, it also kills beneficials. Because it is a contact spray, it can be absorbed through the skin. Nicotine sulfate is less toxic than straight nicotine, and was once packaged under the trade name Black Leaf 40. Whenever handling nicotine of any kind, always wear protective clothing and gloves.

Rotenone is extracted from the roots of many different plants. It is available as a dust, wettable powder or as a liquid and is registered for edible crops and ornamentals. Though it’s deadly to fish, it is only moderately toxic to humans and animals. Rotenone is both a stomach and a contact poison that slows the breathing and heart rate. Since we apply it mainly by dust, always wear a mask when applying this material.

Ryania is derived from a South American shrub, Ryania speciosa. It simply makes bugs too sick to eat. It is quite selective of its prey, so read the label. Make sure your target insect is listed. Because it persists in the environment longer, keep in mind the application dates and the harvest dates.

Pyrethrum is extracted from the seeds of a specific chrysanthemum. It is a contact spray that must be sprayed directly on the insect to paralyze it. If only a little touches the insect, the critter can recover completely. For this reason, many times pyrethrum is mixed with rotenone, as found in Red Arrow. Pyrethrum is relatively non-toxic to humans, but slightly toxic to fish.

Sabadilla comes from the seeds of a South American lily. It is a dust that has a low toxicity to most animals and birds, mainly because it breaks down rapidly under light. Because it can irritate the nose and throat, always wear a mask when applying this material.

Bt - Bacillus Thuringiensis - is a bacteria applied as a spray or dust to control caterpillars. It’s also sold under the name Israelensis (Bti) for mosquito control and Bt-San Diego for controlling Colorado potato beetles and other chewing insects.

This is a highly toxic spray, but only to the specific insects. It is relatively harmless to other insects, pets, the environment or humans.

Remember, natural or synthetic, all pesticides kill. Please use them responsibly and safely.

Note

Last call for the upcoming Friends of Manito tour to four of the Northwest’s premier gardens: Ohme, the Bloedel Reserve, Butchart Gardens and the Bellevue Botanical Gardens.

The tour, departing Wednesday and returning May 18, includes round-trip bus transportation, four night’s accommodations, three ferry rides, all garden admissions and two boxed lunches.

The cost is $330 per person based on double occupancy. Call Diane Kelly at 326-9501 for reservations and information.

, DataTimes The following fields overflowed: CREDIT = Phyllis Stephens The Spokesman-Review