Soil Conditioning
What is Organic Soil?
Organic soil refers to the organic matter component of soil, consisting of plant and animal detritus at various stages of decomposition, cells and tissues of soil microbes, and substances that soil microbes synthesize. One way that may be easier to think about it is to substitute the word “organic” for the word “living.” Organic soil is a soil that is created by the decomposition of plant and animal materials to create a nutrient and mineral rich mini-ecosystem with microorganisms that feed and breathe life back into the soil. Or, to put it another way, organic soil is how soil exists in nature. Organic soils can help improve the native soil found in your garden or landscape! By adding organic matter back into your native soil, you can turn nutrient deficient, difficult-to-grow-in dirt into thriving, living soil. Knowing the different soil types can help you determine how best to treat your soil and how to enrich it. Soil types from sandy to clay to silt can each be improved with organic matter.
What is the Difference Between Soil Amendment and Fertilizer?
Soil amendments are anything mixed into topsoil to promote healthy plant growth. They function in a number of ways. For example, they may change the pH of soil or supply nutrients. Jefferson Landscape and Design uses a 4-4-2 soil amendment with our soil. That is to say 4% Nitrogen, 4% Phosphorus, 2% Potash (Potassium). Nitrogen (N) is a building block for growing new stems and leaves, plus it is a necessary part of chlorophyll, which makes the leaves green and helps plants photosynthesize. Phosphorus (P) is needed for developing flowers, fruits, and root systems. Potassium (K) keeps roots healthy and also aids flowers and fruits. It helps plants tolerate stress, such as drought.
Fertilizers are primarily valued for their ability to supply additional nutrients, but they are often overused, and because of that reason alone we should stick with the organic varieties. Even manure, when too much is applied, can lead to nutrient leaching and excessive growth that inhibits proper crop development. When using your own urine as a fertilizer (yes, you can!), one gallon should cover a 10 x 10 area and is good for a couple of weeks. The addition of urine might even benefit soil pH slightly, since many soils tend toward acidity.
The pH of your Soil
The vast majority of flowers, perennials, vegetables, and fruits grow well in a neutral soil pH between 6.2-7.0. But some plant species require an acidic soil for optimum growth and health. pH is the measure of how acidic or alkaline your soil is: 7 is neutral; lower numbers are more acidic, and higher numbers are more alkaline.
The pH scale is logarithmic, meaning that a change in 1 pH unit is a 10X change in acidity or alkalinity. A soil pH of 6 is 10 times more acidic than a soil pH of 7; a pH of 5 is 100 times more acidic than a pH of 7. So, it’s important to know the natural pH of your garden soil (the pH you can expect across your property) and if a particular plant requires an acidic soil or neutral soil. The only way to know your pH definitively is to buy a testing kit at a garden center or online.
Most plants do just fine in neutral soil. But some plant species perform middling to poorly in neutral soil. Lowering the pH of your soil slightly below neutral can lead to increased yields and help crops fight off pests and disease better. For gardeners growing an acid loving plant like blue hydrangea or azalea, learning how to make soil acidic is important.
Hydrangeas will grow perfectly well in a soil pH of 7.0 where their flowers will be pink. But if the soil pH is below 5.0, the flowers will be blue (some soil acidifiers are sold specifically for this purpose). Do your research before planting and don’t assume that fertilization is the problem if a plant is struggling – it could very likely be the soil pH.
How Do I Make My Soil More Acidic?
If your plants aren't growing in your soil conditions because of too much alkalinity, then it may be necessary to raise the acid level in your soil’s pH. One of the easiest ways to make soil more acidic is to add sphagnum peat. This works especially well in small garden areas. Simply add an inch or two (2.5-5 cm.) of peat to the topsoil in and around plants, or during planting. For another quick fix, water plants several times with a solution of 2 tablespoons vinegar to a gallon of water. This is not really practical for ongoing watering and probably better for adjusting the pH in container plants, but we all get in a pinch sometimes. Acidifying fertilizers can also be used to help raise acidity levels. But again, these are easy to over use and therefore we suggest always erring on the side of caution if they must be used at all.
Types of Plants Grow in Acidic Soil Include:
American Bittersweet Apple Azalea
Balsam Fir Bayberry Beech
Begonia Blackberry Black-Eyed Susan
Black Raspberry Blueberry Calla Lilies
Camellias Carrot Cauliflower
Celery Chestnut Clematis
Cosmos Crabapple Crape Myrtle
Cucumber Dicentra Dogwood
Eggplant Fraser Fir Fringe Tree
Garlic Gardenias Gladiolus
Grapes Hemlock Holly
Hydrangea (for blue flowers) Iris Juniper
Lily-Of-The-Valley Lima Beans Lupine
Maple Leaved Viburnum Marigold Mountain Laurel
Narcissus Nasturtium Norway Spruce
Pansy Parsnips Pine
Pin Oak Potato Pumpkin
Purple Coneflower Red Oak Red Pine
Red Raspberry River Birch Rhododendron
Rhubarb Rose Rutabaga
Saucer Magnolia Scotch Heather Serviceberry
Snap Beans Snapdragon Spruce
Squash Strawberry Sumac
Sweet Corn Sweet Pepper Sweet Potatoes
Tomato Watermelon Wayfaring Tree
White Oak White Pine White Spruce
Willow Winged Euonymus Zinnia