For thousands of years coastal inhabitants have been heading to the beach to gather seaweed to use on their gardens or farms. Whether harnessed as a broad spectrum fertiliser, mulch or pest controller, the benefits and low cost make kelp a no-brainer of an ally to the gardener. There are more than 10,000 types of seaweed and it can readily be found on most Australian beaches. On your collection excursions, don't forage in areas that are likely to be polluted, be sure to get the fresh stuff strewn up on the beach, nothing actively growing on the rocks, and nothing too dry or old, and make sure to give it a rinse at home to remove any excess salt.When mulching with seaweed, it's best to apply thickly - thicker than intuition might tell you - as it will reduce down vastly as the moisture evaporates. Laying it down at the end of autumn/start of winter will keep ground warm, moist, and healthy. Likewise, in summer it will keep the ground cool, moist, and rich. Digging it in later can add a great conditioning factor to your soil too.When mulching with kelp, you can expect the following results:
As with all nitrogen rich fertilisers, be careful how much you used near root crops, as it can cause splitting. Bear in mind that kelp does contain high levels of salt along with other nutrients so while it is unlikely to do much damage, don't add piles of seaweed to highly salt sensitive vegetables. (Add it to your compost instead. It will love you for it.)Worms don't like seaweed much by the way, so bear this in mind.Image: Kuttelvaserova Stuchelova/Shutterstock