When we make tea for drinking, we are extracting the flavonoids, essential oils, vitamins and minerals from the plant material. We brew the tea, strain out the solids and sediment, and drink the tea. Our bodies take up the nutrients we need, and the excess is flushed out in our elimination processes.
A similar process takes place in the garden with the use of natural fertilizers. Liquid fertilizers are multi-taskers, feeding and watering plants at the same time. Using plant- and animal-based ingredients to fertilize the land is a common practice among organic gardeners and farmers.
Brewing your own fertilizer tea can be messy and stinky. Live bacteria and algae will multiply rapidly, which is good for the soil but intense for the senses. Think of these teas as earth medicine — even if they smell a bit brawny.
First Teas — Something Fishy
When each of us began gardening organically more than 30 years ago, the first fertilizer we used was liquid fish emulsion. It came in a brown plastic bottle full of a thick, dark brown concentrate, which smelled as fishy as its name. The directions were to mix it with water and water the plants with the diluted solution. These were our first experiences using a type of tea to feed our plants. Later, we tried a liquid kelp fertilizer that was also a concentrate with similar instructions, although besides watering the plants with it, the label suggested using it as a foliar spray. Fish emulsion and liquid kelp are excellent fertilizers we still use today, but over the years we’ve added other natural and botanical substances to our arsenal of nutritive garden teas.
Manure Tea Experiences
Living on a biodynamic farm in Italy, Susan learned about the art of manure tea. There was a large old bathtub outside by the garden for this purpose. The farm had chickens, ducks, geese and rabbits, and the manure from these animals was put into piles and aged for six months to one year. A large bucketful of the aged manure was dumped into the bottom of the tub, and the tub was filled with water. This was allowed to sit for at least three or four hours and stirred every now and then with cherry-tree branches that had been tied together loosely to form a broom-like whisk. We filled the watering can or buckets from the tub and carried this smelly water to each of the plants in the garden. The tea was prepared whenever there were new transplants, and also was used throughout the growing season. It was amazing to see how well the plants responded to this manure tea.
While gardening at the Ozark Folk Center, Tina made her first manure tea. She would go to visit Bob the mule and gather his manure. After letting the manure age, she’d put a gallon or so of it in a 5-gallon bucket, add water and stir with a hickory stick. Bob’s manure tea fed the herbs and old-time flowers planted around the park.
How to Use Fertilizer Teas
We use these teas when we are planting or transplanting, during the growing season when we water and when the plants appear to need a boost. Teas with high amounts of nitrogen should be used only during periods of active growth. Teas can be used strained or unstrained. If there is a lot of sediment or if there is a slurry left, we add this to the compost pile or dig it into the garden soil.
Another good way to administer botanical teas is by foliar feeding. Foliar sprays must be well-filtered so they do not clog the sprayer. You have to do this in manageable quantities. Pour the mixture through a strainer lined with fine cheesecloth or use a jelly bag. The idea is to get rid of all of the particles because they will stop up the valve of your sprayer. The teas are best used in the late afternoon and very early morning, and never during periods of temperature extremes. Late afternoon is the best because pores on the underside of the leaves tend to open at night. The pH of the tea should be slightly acid, about 6 to 6.5. Using a pH test kit available at any gardening store, test the tea and add either a bit of baking soda to increase alkalinity or vinegar to increase acidity. All our teas should be safe for foliar feeding as long they are well filtered.
Easy to Make
Add a small coffee can of rabbit pellets (alfalfa) to a 5-gallon plastic bucket and then fill with water and 1 tablespoon of molasses. Molasses speeds up microbial growth. Pour the mixture back and forth to a second empty 5-gallon bucket several times (a process called boxing). Let it age three days, boxing it back and forth at least once a day. What do you get? Alfalfa tea for plants. Water your new plantings with it and you’ll have the earthworms doing circus tricks in your soil.
Compost, horse and rabbit manure, bat guano, chamomile flowers, spirulina and culinary and medicinal herbs are other ingredients used to feed plants and soil. Adding humic acid to the formulas increases the growth and vitality of container and garden plants. Liquid humic acid is derived from decayed organic matter called humates. Humates chelate (combine) plant nutrients and release them to plant roots. Soils high in humus have good composition, water retention and aeration. By using plant- and animal-based teas, we feed and increase that aerobic microherd, which makes nutrients available for happier, healthier plants.
Nourishing Herb Teas for your Garden
Many common garden herbs and weeds can provide nourishment and nutrients for growing plants, just as they would for people consuming them. As you weed, cut back or harvest these leafy garden greens, save them in a basket or bucket and combine or use them singly to make a botanical tea — recycle those nutrients — and fertilize your garden. Prepare a tea by infusing the whole or chopped leaves in water for a few hours or up to a few days, be sure to stir it every now and then. When you apply the tea, it is okay to use the leaves too, although they may be a bit slimy if you infuse them for more than a day. Below are just a few garden herbs we use:
- Chicory, wild and cultivated, is high in potassium and contains calcium and vitamin A.
- Comfrey leaves are a good source of calcium, phosphorus and potassium, and contain vitamins A and C, as well as other trace minerals.
- Dandelion leaves contain vitamins A and C, as well as calcium and potassium.
- Nettle leaves are packed full of nutrients from vitamins A, C, K, B1, B2, B3, B5, calcium, magnesium, phosphate, phosphorus, potassium, boron, bromine, copper, iron, selenium and zinc.
- Parsley leaves provide a good amount of vitamins A and C, as well as iron, copper and manganese.
- Perilla leaves are loaded with iron and calcium.
- Watercress contains vitamins A, C, E, B3, B6, calcium, manganese and iron.
What They Are, and What They Do
Nutritive teas extract the water-soluble nutrients from the natural fertilizers, and — if brewed for three days and stirred or boxed — increase the friendly flora or aerobic microherd of the tea (a phrase to describe the beneficial organisms that consume fungal and bacterial diseases, break down organic matter into humus and make nutrients available to our plants). Here are the specifics on each type of tea for the garden.
- Alfalfa meal (rabbit pellets) N: 2.45 percent, P: 0.5 percent, K: 2.1 percent (see "The Big Three" for details on these key elements and their symbols). Alfalfa is a legume grown as a cover crop to fix nitrogen in the soil, and it is used as a high protein feed for animals. The roots plunge as deep as 23 feet, capturing and transporting plant nutrients to the surface. As a plant fertilizer, alfalfa is valued for its trace element content, including sulfur, iron, magnesium, manganese and selenium. Alfalfa meal contains the growth stimulant, triaconatol, that when sprayed on a variety of crops increases growth and yields. Soak the pellets for three or four hours to dissolve them, boxing a few times, then use as a tea; or add the molasses and soak for three days for an even richer bacterial nutritive tea.
- Algae are microscopic green plants that participate in the global environment in huge and diverse ways. We use two phyla of algae in our fertilizer teas.
- Blue-green algae (spirulina and chlorella) are highly nutritive human supplements containing protein, B vitamins and a host of other attributes. In gardening, they are used to reduce shock when transplanting. Make a paste with 2 tablespoons blue-green algae to 1⁄4 cup water. Combine the paste with water, stir or box and use right away. You also can grow more blue-green algae by making the tea and adding a tablespoon of quicklime to the water. Store in a warm place with sunlight, box daily, and dip from the top. Dilute this with water to feed plants. Refill the blue-green algae bucket and grow some more living fertilizer.
- Kelp (seaweed) is a wonderful organic fertilizer, which may come from any number of plants that grow in the sea. High in potash, it also contains nitrogen, potassium, trace minerals and chlorophyll. Kelp helps to release minerals in the soil and has growth-producing hormones that aid in plant maturation. It is available in dried, powdered form as well as liquid concentrate, and is easily made into teas. Follow directions on the container for mixing.
- Bat guano is mined from caves of the Southwest and the South Pacific coastal islands west of the Andes. Nutrients, particularly nitrogen, are preserved in a mixture of droppings and decomposing bat bodies. Fertilizer values vary from N: 5 to 6 percent, P: 2.5 to 16 percent, K: 0 percent. Combine with water and box; then let stand overnight while the hard clods begin to soften and dissolve. Dip from the top when you feed the plants. Add more water to remaining solids and use again. This can be done for several days, then add any remains to the garden or the compost heap.
- German chamomile flowers (Matricaria recutita) have anti-fungal properties that we have observed preventing damping-off disease in seedling flats. Flowers are steeped in cold water for one or two days, then strained and sprayed on the potting mix just before planting.
- Compost, when well made, is our first line of organic plant nutrition. The compost contains nitrogen, phosphorus, potassium, calcium and many trace elements. It inoculates the soil with beneficial micro-and macro-organisms (the aerobic microherd) plus nucleic and carbonic acid. Compost tea is a mainstay in our feeding and watering programs. It never hurts to use compost in any fertilizing tea blend. Compost can be mixed with water and boxed or stirred and allowed to stand for three to four hours before using, or it can be allowed to brew for a couple of days, boxing back and forth every day.
- Fish emulsion and fishmeal are made from dried ground fish. The former is made into a concentrate, and the latter is a powdered meal. The odor of both can be offensive to some, and it stays around for a day or two. However, it is a fast-acting fertilizer and makes a good tea for transplants and throughout the growing season. N: 4 to 10 percent, P: 3 to 9 percent, K: 0.3 to 1.9 percent. Follow directions on the container for mixing.
- Herbs and greens contain minerals, vitamins, enzymes and essential oils that we process in water for our bodies and our gardens. We research the anti-fungal and insect-repellent herbs to make remedies. We have an overabundance of some plants and are happy to use the bounty in botanical teas to nourish the garden. Cold water will extract much of the nutritive material from plants for use in the garden. We gather the plants, roughly chop them and cover with cold water, leave them to macerate for three days, then strain the liquid. We use the finished tea as a concentrate, adding it to irrigation water, or use it undiluted around plants in need of stronger medicine.
- Manure, regardless of its source, provides the three main elements, as well as trace minerals. Most importantly, it furnishes organic matter, becoming humus in the soil, which helps plants absorb nutrients. Fresh manure is rich in nitrogen and generally should not be used directly on plants because it may burn them. Horse, poultry and sheep manure are highest in nitrogen and are considered hot. It can be put into piles to age (for six months to one year), worked into compost, or it can be made into manure tea and fermented for at least 30 days. It can be worked into the garden soil: However, you must wait for at least four weeks after applying fresh manure before planting. On the other hand, aged or composted manure can be used in the garden or made into tea without any wait. Aged manure can be mixed with water and boxed or stirred and allowed to stand for three to four hours before using, or it can be allowed to stand for a couple of days, stirred daily. Manure tea is especially good when transplanting and before plants flower.
- Gray water is basically the leftovers from other household water uses. Over the years, both of us have lived in drought situations in different places. When water is plentiful, we don’t think about how much we use, but when it is in short supply, we realize what a precious commodity it is. So we recycle water whenever we can. When we make a smoothie, we rinse out the blender and water our plants with this nutritious water. We rinse the grounds from our coffeepots and the tea/herbs from our teapots, swishing the water around to loosen the particles and use that to water our plants or pour on the compost pile. When we boil a large pot of water to cook pasta or fill the canner for a hot -water bath, we let the water come to room temperature and use it for watering. We wash our dishes with biodegradable soap in a basin and use another basin for rinse water. Once cooled, this gray water goes to water our plants, too. The nutrients from this saved water are a kind of household tea that provides plants with vitamins and minerals, instead of being thrown away every day.
Plants use three main elements — nitrogen, phosphorus and potassium (known by their chemical symbols, NPK) — for growing green leaves, making seed and fruit, and growing cells. The standard labeling always lists these three essential chemicals in this order, N-P-K.
- Nitrogen (N) is necessary for aboveground growth of plants. Nitrate, the compound produced when nitrogen combines with other elements to produce a salt, produces green leaves. Ammonia nitrogen (NH3), the compound produced by nitrogen and hydrogen, is used by plants to produce fruit and seeds. Ammonia nitrogen is a gas and volatilizes into the air. If there is too much nitrogen, plants have rapid growth but tend to be weak, which makes them break easily and be more prone to disease. When there is not enough nitrogen, plants are stunted and foliage is yellow, not healthy green. The best organic sources of nitrogen come from plant and animal by-products such as alfalfa pellets (2.45 percent), blood meal (10 to 14 percent), bone meal (2 to 4 percent), fish (8 percent), ground poultry feathers (15 percent), manure (varies) and soybean meal (7 percent). We choose alfalfa, fish and aged manure for making fertilizer tea. If you feel hesitant about manure-borne bacteria, stick with alfalfa or fish.
- Phosphorus (P), or phosphate, helps plants transport and assimilate nutrients. During photosynthesis, it helps the plant produce sugars. Plants cannot grow or fight disease without it. Phosphorus is crucial for plants to develop healthy root systems, set fruit and mature. For the organic gardener, soft rock phosphate (20 percent), bone meal (15 to 25 percent) and fish emulsion (7 percent) provide the highest percentages of naturally occurring phosphorus. We use bat guano (5 to 6 percent), fish emulsion or fishmeal to nourish our plants in phosphorous.
- Potassium (K), commonly called potash, enables plants to develop strong, thick stems, healthy roots and large, plentiful fruit. Potassium plays a leading role in plant sugar production. Manufacturing sugar helps a plant protect itself from intense heat and cold, and aids in disease resistance. Compost and manure are good sources for potassium, as are kelp (2.25 to 6.5 percent) and natural minerals like greensand (7 percent) and granite dust (3 to 6 percent). Hardwood ash (10 percent) is rich in potash but dries the soil and may create an overly alkaline soil if used in large quantities. For a nutritive tea rich in potassium, we prefer kelp and aged manure.
There are a total of 16 nutrients essential for the healthy growth of plants. Besides the big three, plus carbon, hydrogen and oxygen, 10 other chemical elements are necessary in the soil. These nutrients are called trace elements and are needed in much smaller quantities. They are boron, calcium, chlorine, copper, iron, magnesium, manganese, molybdenum, sulfur and zinc. Some, such as calcium, are needed in larger quantities. Calcium (Ca) is a major building block for plant tissues and is the major element against which other elements react to release energy. Calcium neutralizes toxins and is needed for all plant growth throughout the life of the plant. Calcium is usually added in the form of dolomite lime to correct soil that is too acidic.
Principal trace elements are needed in such small quantities that compost, ground mineral rocks and agricultural meals such as alfalfa should provide all that are necessary. Alfalfa’s deep roots reach trace elements contained in the sub-soil. Use this and other green plants in your compost. All the trace elements are essential to plant growth and fruiting. Organic matter holds these elements and releases them slowly to plant roots. Treating your plants to a fertilizer tea party will provide them with the nutrients they need in low, naturally occurring amounts. An added bonus is that soil organisms essential for plant health crash the party and are fed at the same time.
Susan Belsinger is a longtime contributor to The Herb Companion. She writes, cooks and gardens from her home in Maryland. Tina Marie Wilcox enjoys gardening in the Heritage Herb Garden at the Ozark Folk Center in Arkansas.