A dose of some form of "bioactivator" three or four times a year helps plants of all kinds utilize the nutrition from the soil or fertilizer more efficiently. Bioactivators are not fertilizers in the strict sense of the definition. They are more like tonics, or vitamins, enhancing the general health and condition of plants and making them much more resistant to drought, diseases, and in some cases, insects.
Choosing Bioactivators For Plants in the Landscape
Seaweed or Kelp Products - Until recently, seaweed extract has been the most common bioactivator for plants. Seaweed (kelp) is sold as a liquid or powder concentrate of one or more varieties of kelp. Seaweed is totally safe and provides some 60 trace elements that plants need in very small quantities. It contains growth-promoting hormones, and has a slow release rate. A great source of vitamins and beneficial enzymes for plants, its carbohydrates help plants absorb otherwise unavailable trace elements. Spraying plants with seaweed extract stimulates leaf bacteria to increase the rate of photosynthesis.
Seaweed may be introduced directly into the soil, rather than sprayed onto plants. In the soil it stimulates soil bacteria. This in turn increases fertility through humus formation, aeration, and moisture retention. In this improved bacterial habitat, the ability of nitrogen-fixing bacteria to fix more elements from plant residues and soil minerals is enhanced.
A good general recipe for the powdered form of seaweed, sold as kelp meal, is 1 pound of kelp meal per 100 square feet of garden, applied each spring. Divide this quantity into three or four portions and apply it once a month for the first 4 months of the growing season. Spray the liquid form, once a month for the first 4 or 5 months of the growing season.
For more details about using seaweed and kelp go to the files Using Seaweed In The Landscape
What About Compost?
Home made compost should not be considered a substitute for general purpose or "main meal" fertilizer. It is an outstanding soil amendment and does offer many micronutrients to plants. However, because homemade compost is generally low in nitrogen and phosphorus it does not provide a complete meal. Use it instead as a supplement to your fertilizing program.
For more information see the file Composting
Brown Zinger - Suspend a cloth bag filled with compost or manure like a tea bag in a water-filled airtight container. Any manure is all right, either a dried product purchased at the store or fresh manure from a local farm or stable. Keep the container covered to prevent the escape of nitrogen as gas. After a day the liquid will have leached out nutrients from the bag of manure and the snack will be ready. Dilute the liquid so that it looks like weak tea. Fill a watering can with it and pour it into the soil around the plants.
Plants should be well watered before they are fertilized with this solution. The best time to use liquid manure or compost is right after a rain. Keep the liquid away from plant stems or leaves so that it does not "burn" the tissues. If the solution seems too strong, dilute it with more water.
Some New BioActivators
There are now on the market a number of new bioactivator products. They are not seaweed or kelp compounds, but they do essentially the same job. They improve each plant's ability to produce its own food and they increase pest and disease resistance. These products are either sprayed on plant foliage or watered into the soil. Use them with the same frequency as seaweed products. For complete information about using these new products go to New Technology in Plant Growth Activators
Don't Forget Earthworms
Earthworms do lots of good things for the soil in your yard. They aerate it as they tunnel through it on their daily business. Best of all, they manufacture fertilizer for all the plants in the yard for free--about 2 pounds of nitrogen per thousand square feet. Take care to keep them happy and productive. Compacted soil and fast acting nitrogen fertilizers poured on the soil will drive them away.
Earthworms produce their weight in castings every day, and worm castings are an absolutely wonderful fertilizer, with nutrients available in a form all plants can use. In a 200-square-foot garden for example, with a density of only five worms per cubic foot (considered a low population), earthworms provide over 35 pounds (about 1/3 pound per worm) of top-grade fertilizer during each gardening year. They also spread it evenly throughout the top 12 inches of the soil, and in many cases they will go much deeper, sometimes as far down as 6 feet.
For many details about earthworms see the file Encouraging Earthworms