Raised bed gardeners beware, standard potting soil and/or soil that you get from a garden center is low in organic matter, has no bug life, has been sterilized and typically has the minimal amount of nutrients and minerals needed to provide enough life to support vegetables and flowers for one to two years. So you either need to purchase new soil one to two years to refill your garden beds with, which can be expensive over time, you can add chemical fertilizers which will damage your soil over time, or you can plant specific crops that fix nitrogen, phosphorous, potassium and more in your soil. I highly recommend the third option and we’re going to explore how raised bed gardeners can enhance the life of standard potting soil and soil that you buy from garden centers without adding chemicals fertilizers to their soil.
Soil is alive, yet when you sterilize soil (this is a very common practice in bagged soil or soil that comes from a garden center) you kill all of the soil’s life. Potting soil typically has those white, rock-like substances in them and yes these white rock-like substances are fertilizer and these fertilizers pellets break down in a year or so which leaves the soil without anything to support plant growth. Garden center soil is sometimes amended with compost or other nutrient mixes and once again, compost and nutrient mixes only last for a short period of time before they get depleted and then you’re left with lifeless soil. So what is a raised bed gardener to do?
Plant peas, beans, clover, alfalfa, peanuts and other nitrogen-fixing crops. Nitrogen-fixing crops have bacteria that grow on their stems that can take the nitrogen that is in the air that cannot be used by plants or humans and convert it into a usable form to provide the soil with a steady supply of nitrogen. Nitrogen is one of the key nutrients that vegetables need to grow and all soil can store nitrogen.
Cover cropping your soil at the end of the season and then laying the cover crops back over your soil will provide calcium, phosphorus, potassium and more to your soil. Common cover crops include hairy vetch, oats, field peas, buckwheat and rye. If you plant cover crops before winter, then kill them in the spring before they flower and finally lay the killed cover crop on top of your soil, they will break down over time and supply your soil with these key nutrients. One of the major factors in cover cropping is to plant your seeds underneath the cover crops so that they can directly receive nutrients while they are growing.
While cover crops are a fantastic panacea for lack of nutrients in the soil, not every cover crop works in every environment. So before purchasing a cover crop you will want to find your USDA Plant Hardiness Zone and then research cover crops that grow well in your plant hardiness zone. Certain cover crops also support certain vegetable growth and you also need to make sure that the cover crops that you are going to purchase are beneficial to the vegetables and/or flowers that you want to grow.
Planting cover crops and nitrogen-fixing plants can make a huge difference in adding life to your soil and when it comes to adding life to your soil this is something that you have to do on a yearly basis. So make sure to plan out your cover crop seeds on a yearly basis and plant nitrogen-fixing plants on a yearly basis as well. Doing so will ensure that you can keep your soil healthy and strong for years to come and ensure your raised beds gardening success