The secret to landscapes and gardens that flourish is getting the soil in shape with all the nutrients your plants require. There are many ways to achieve healthy productive soil, but the first step is to learn what you have.
If you were present during some of the excavation work around your home, you may have a good understanding of the composition of the layers of soils on your property. Your septic engineer can also give you some insights about drainage and soil composition as these were analyzed when developing the septic plan. In Maine, many areas have a substrate of blue clay, which can limit the amount of drainage if it’s close to the surface. Other, more sandy, substrates may require adding elements to hold water in the soil so plants don’t dry out.
For an assessment of the topsoil, many companies offer soil analysis kits. Most states have soil testing labs, often affiliated with universities, including one online listing provided for organic farmers. Another site, GrowOrganic.com sells testing kits homeowners can set up and use on their own.
Know your soil nutrients
There are five soil nutrients necessary for healthy plants. Deficiencies identified by the soil testing results can be remedied through amendments to the soil. The nutrients are: nitrogen, phosphorus, potassium, calcium, and trace minerals. Each provides for a different part of a healthy crop and deficiencies may affect the success of your gardens. Here are some suggestions for amendments and the plant requirements that each nutrient meets:
Nitrogen (N) is needed to provide vigorous growth. Common amendments to add nitrogen to soil include blood meal, cottonseed meal, PVFS liquid fish, fish meal, pellet fertilizers and others. Some mulch produced in coastal regions add fish waste, including lobster shells and fish carcasses to their mixture of organics to add nitrogen into the blend. Certain plants are known as nitrogen fixing plants and can be grown alongside or in rotation with other plants to keep nitrogen balances good over the long term. Clover is one that is easily introduced into lawns and will help to establish a healthy green lawn quickly. For your flower bed or vegetable garden, nitrogen fixing plants include lupines, vetch, certain members of the pea and bean family, peanuts and fenugreek, an herb used in Indian cooking.
Phosphorus (P) is used by plants to develop healthy flowers, fruit, and root development. Soft rock phosphate or bone meal can be added to the soil to add phosphorus.
Potassium (K) is used by plants for the formation of sugar. As a result potassium is key to a plant’s vigor and resistance to disease. Potassium can be added via sulfate, potash, or greensand.
Using an NPK blend lawn food, like Scott’s Organic Choice Lawn Food (right) is a good bet for a healthy lawn.
Calcium constructs plant cell walls, much like it helps animals build strong bones. Many soils are low in calcium and the type of amendment required will depend on the pH of the soil. For low pH soils, mined limestone or oyster shell lime can add calcium and adjust pH levels. In neutral or high pH soils, gypsum works best, and also provides sulfur, a trace mineral.
Trace minerals are the vitamins that plants need for healthy growth. Most compost, seaweed meal or trace mineral additives can boost these nutrients.
Whether it’s a new lawn, a floral garden or a vegetable garden, starting with well-nourished soil can be the first step in a successful garden each year.