If someone wanted to add just one thing to their feeding schedule, I’d recommend water-soluble kelp extracts. Seaweed extract has multiple uses. It can be used as a seed soak, a root stimulant or as an excellent foliar spray. It can be misted on the leaves of mother plants to encourage more lateral branch development for better cuttings, and it can be used to improve the color, flavor and nutritional value of your favorite fruits and vegetables. Kelp is an excellent addition to your garden, but if you want even better results, try combining seaweed extracts with humic acid. It’s a powerful combination.
Seaweed extracts and humic acid have a synergistic effect. In other words, they work better in combination than alone, magnifying their benefits to the plant. Virginia Tech did a 10-year study on organic bio-stimulants, and they found that combining humic acid and seaweed extracts in a 5:2 ratio worked 50% better than either product alone. That’s good news for gardeners. First, the studies showed that the humic acid/ seaweed combination stimulated more lateral root development and root mass, allowing the plants to take up water and nutrients more efficiently and that translates into higher quality and yield. The researchers also found that the treated plants were better able to handle heat and water stress, and they recovered from stress much faster than the untreated control. Plus, the plants treated with the humic acid/ seaweed combination had better color and accumulated significantly higher levels of vitamins and natural plant protection agents.
The researchers at Virginia Tech made another interesting discovery. They found that plants treated with the humic acid/seaweed combination produced 50% more SOD (superoxide dismutase). SOD is a powerful antioxidant enzyme and plant protection agent. SOD protects the cell membranes, chlorophyll membranes and mitochondrial membranes from harmful oxidative stress. Intact cell membranes are very important for plant growth. Chlorophyll membranes are needed for photosynthesis; mitochondrial membranes are needed for cellular metabolism; and plasma membranes regulate the flow of water and nutrients into and out of the cell. Disrupt the cell membranes, and the power-plant of the cell begins to shut down and the cell walls begin to collapse. Fortunately, under ideal conditions plants produce all of the SOD that they need to protect themselves. But under stressful conditions such as heat stress, drought stress, salt stress or UV stress, plants can’t produce enough SOD to protect themselves from the barrage of damaging free radicals. Using a combination of humic acid/seaweed helps the plants build a reserve of SOD and keeps the plants growing at peak efficiency.
Using kelp and humic acid together is a wise choice and it can even help save money. Concentrated seaweed extracts are much more expensive than humic acids. So the 5:2 ratio of humic acid to seaweed is a very good deal. Just use the humic acid at full strength and the seaweed extract at half strength. It will work 50% better than seaweed alone, and save you money at the same time.
Harley Smith is a free-lance contributor to Garden & Greenhouse Magazine.