Organic Herb Gardening. The decision to grow herbs organically, no matter the placement, i.e., indoors or outdoors, requires that the gardener understand what the word organic implies. To grow or garden herbs organically the gardener must plan three essential organic gardening factors with care and obedience: 1) Prepare the soil. 2) Use only organic fertilizers. 3) Use organic pesticides.
If the plan is to become a certified organic garden then the scope of the plan is beyond this article. If you want to be as “organic” as practical in your situation, then let’s begin.
1. Prepare the soil. Organic soil amendments to improve the nutrient content and physical characteristics of the soil are extremely important in establishing an organic garden. Decomposing organic matter in soils are nutrient rich sources for plants, improve soil structure, water-holding capacity and make micronutrients available.
Adding compost within the form of yard clipping, plant cuttings, shredded paper, animal waste, straw, sawdust and other organic materials is a superb inexpensive method to amend garden soils; however care have to be taken to ensure the compost has thoroughly decomposed before use. Unprocessed compost can contain fungus, bacteria, diseased plant material and pest eggs and larva. Some organic experts recommend solarizing the soil by using plastic sheeting before planting to sterilize the soil.
For container planting, ensure the potting material meets similar standards as organic compost. For commercial potting soils read the labels to ensure soil sterilization before use.
2. Organic fertilizers. Of the nutrients required by most crops, three nutrients, nitrogen, phosphorus and potassium (N, P, K) are of primary importance.
Nitrogen (N) provides the above ground growth of plants. Large green leaves, tall vigorous plants. As a significant component of chlorophyll nitrogen is a crucial element in photosynthesis. Nitrogen will be introduced to the soil through blood meal, fish meal powder and canola meal. A lot nitrogen causes the plant to out grow its roots leading to a narrow long weak shoots. Too little nitrogen and the plant will slow or stop growth and drop leaves.
Phosphorus (P) is important for overall plant growth. Necessary for good root growth and plant structure. Phosphorus stimulates plant growth and maturity because of its role of transferring energy from one reaction to cause another reaction in plant cells. Available in manure, bone meal, fish bone meal and plant waste compost, organic phosphorus have to be “mineralized” into an inorganic form to be utilized by plants. Due to over use, soil testing for phosphorus is recommended.
Potassium (K) sometimes call potash, a term derived from earlier methods used to produce potassium. Potassium provides for overall plant vigor and health, it can be crucial in protein synthesis and photosynthesis and water absorption. Organic sources of Potassium include Greensand, manure and composts, wood ash from hardwood trees, Langbeinite, referred to as Sul-Po-Mag and seaweed.
3. Organic pesticides. All pesticides, organic and synthetic, are governed under the Federal Insecticide, Fungicide and Rodenticide Act. All organic pesticides must meet the factors of the USDA’s National
Organic Program Rule (NOP). The EPA provides labeling approval for
organic pesticides. Herbs are not always listed as one of many plants the pesticide can be utilized. So you’ll want to check the label before using the product.
To get an idea about herbs and pests, research THE HERB SOCIETY OF AMERICA article on pests and Basil or Texas A&M’s research on Management Of Insects On Herbs.
Insecticidal Soaps: More often a synthetic, it’s a contact pesticide, the soaps kill by washing away the insects’ protective surface coating and disrupting membrane functions inside the insect and by smothering soft bodied insects. Ensure the soap label states herbs are acceptable and that the soap meets EPA guidelines as an organic insecticidal soap.
Neem: Neem based pesticides are developed from the neem tree which is indigenous to India. The neem tree produces a compound called azadirachtin which allows it to protect itself from damaging insects. Azadirachtin is a slow acting growth regulator that may be a broad spectrum insecticide. Not all neem products specify herbs as a plant which the products may be used on.
Diatomaceous Earth: Composed of diatoms, which are tiny fossilized shells of marine plants. Likened to a mineral dust, it has razor sharp edges that cut through the protective covering and enters the insects’ body.
Diatomaceous Earth works by dehydrating the insect.
Pyrethrum: The most commonly used chemical in organic gardening, pyrethrum is produced from chrysanthemums. A robust insecticide, pyrethrum attacks the nervous system of insects. Non-synthetic pyrethrum is taken into account a safe chemical for mammals and can be utilized it the identical day you harvest.
Rotenone: Organic Pesticide extracted from the plants of the Derris genera.
Slow acting poison that’s effective on many insects (flies, caterpillars, beetles). It’s fairly nontoxic to bees and birds but will kill fish and causes Parkinson like symptoms on rats. Rotenone is on the market at garden centers and farm supply stores however no rotenone products are currently approved for organic production by OMRI.
Pesticide Oils: Three several types of oil are used as pesticides or as additive to other pesticides. 1) Petroleum or mineral oils that are distilled from crude oil. 2) Plant and fish oils. 3) Essential Plant Oils, including wintergreen, clove and rosemary. Primarily used to smother insects, oils also might alter insect behavior by disrupting feeding and laying egg. Oils work well on aphids, mites, whitefly and caterpillars.
Bacillus Thuringiensis (BT): Classified as a biological, BT is a spore formed bacteria that must be consumed by the insect to be effective. After entering the insects’ body, the bacteria causes the insect to stop eating and eventually starves to death. Used to treat caterpillars, beetle larvae, fungus gnats and black flies, not all insects are affected by BT and, as in other insecticides, young larvae are more susceptible so treatments should start early in the growing season. BT is accessible at most garden and farm stores and is applied via spray or is dusted on the plant.
Organic herb gardening, and organic vegetable gardening, for that matter, relies on preventive and integrated methods to manage disease and pests in the crops which are grown. With so many products on the market claiming to be organic and so many home remedies offered by the well meaning neighbor it’s little wonder the new gardener may be overwhelmed in their attempt to grow organic herbs.
Of the three essential requirements listed, fertilizers and pesticides probably pose the biggest challenge for brand spanking new herb gardeners. Attempting to decipher product labels that include the term organic or organic like in their branding or description, e.g., organophosphate, (Malathion) or Milorganite (treated sewer sludge). Neither Malathion nor Milorganite are allowed for use in certified organic agricultural production by the USDA regulations. If Milorganite or any other composted sewage sludge is used to grow your herbs, the plants would not be considered organically grown.
Growing herbs organically is an educational experience worth its weight in oregano. The more you learn the more you’ll understand the ecological relationship between organic garden, and agriculture for that matter, and our each day lives.