Seaweeds can fertilize a garden as liquid, as powder or plain.
Some seaweeds, of the brown algae family, contain all three components of fertilizer plus trace elements. Celtic and Scandinavian farmers used it for centuries. Organic farmers still use it to activate compost, as a substitute for manure in the soil or as a folial feeder. Does this Spark an idea?
Benefits
Seaweed contains complex carbohydrates which stimulate soil microbes. It assists nutrient uptake in plants. It defends against soil-borne disease. Its gelatinous nature binds loose, sandy soil.
Types
Kelp, a brown algae, has a translucent lemon yellow appearance. It forms kelp forests on the ocean floor. The tops of the plants can detach in a storm and wash ashore. Laminaria, another group of brown algae, has branches like a candelabrum. Bladder wrack, or rock weed, grows close to shore, anchoring on rocks. It has small, gas-filled vesicles.
Available Forms
The gardener can apply seaweed directly to the soil. Concentrated liquids allow folial feeding. Powdered forms allow several applications.
Uses
Fresh seaweed works as a substitute for manure, rinsed and worked into the soil before planting. Unlike manure, it needs no rotting. Fresh seaweed turned into woody compost activates the pile. The liquid form, after dilution, can be sprayed on foliage. Powdered seaweed made into a paste helps develop top soil.
Warnings
Collecting seaweed may violate local law. Avoid collecting seaweed near a source of pollution. Collecting seaweed may affect an ecosystem. Use it in first stage composting, worms don't like it. Using seaweed as a fertilizer may alter the pH of the soil. Rinsing before application removes salt, but may also remove beneficial alginates.
Tags: brown algae, Fresh seaweed, substitute manure