The soil under your feet may seem irrelevant to your life, but to a plant, it is 'home.' Think of soil as a kind of 'living skin' that covers the Earth. Most of the truly fertile topsoil on the land is only about 30-40 cm deep. Soil is much more than mineral particles. It is made of millions of living organisms and the materials they use or make.
Plants grow at this level and animals go about their daily lives here. A healthy covering of plants can keep the soil cool, moist, living and fertile.
This is the organic layer where most of the 'action' happens. Decomposers "do their thing" by recycling dead plants and animals into organic humus. Composed of the right mix of organic and inorganic particles, this layer can be a rich and hospitable place for plants to thrive by getting available organic nutrients and stored moisture.
This is a mixture of minute mineral and some organic particles in the upper zone. Subsoil is very low in organic materials compared to the topsoil, but it is in this layer that most of the soil's mineral nutrients are found. The clays and minerals broken down from decomposition in the topsoil end up here as water percolates down through the soil. Deeply established plant roots from trees and larger shrubs pentrate this layer for water and mineral nutrients.
Keeping soil fertility high requires some basic knowledge of plant nutrient requirements.
Packaged fertilizers are rated according to the ratio of the three major nutrients contained in the fertilizer.
The three numbers on the package ( NPK rating) are always in the same order (in Canada) and refer to the ratio of nitrogen, phosphorous and potassium in the mixture.
Nitrogen, represented by the first number, stimulates leaf growth and development.
Plants must have nitrogen to make the chlorophyll, enzymes and proteins needed for strong cells that reproduce in a healthy manner. Plant fertilizers targetting green plans, such as grass, contains a high amount of nitrogen.
Phosphorus is represented by the second number of the three. Phosphorus is required by plants for the stimulation of root growth.
Fertilizer used for transplanting seedlings outdoors is typically high in phosphorus. Plants with a healthy root system typically survive much better than those with a stunted root growth.
Perennial plants and shrubs that need to survive the winter benefit from fertilizers high in phosphorus.
The third number in the sequence is potassium. This nutrient builds healthy and strong cell walls, ensures overall plant health, resistance to diseases and prepares the plant for surviving harsh winters.
Potassium is crucial, as well, for flower and fruit development.
Plants that are purchased at retail outlets usually come labeled with sun exposure requirements. Determining how much sun certain plants require is not an exact science and will depend on other factors, as well. The following definitions are the generally accepted standards for most plants on the market.
Full Sun: This means at least 6 full hours of direct sunlight. Plants that thrive with more 6 hours per day will also need regular water to survive the heat. Succulent plants such as cacti have a tougher covering on their leaves to retain moisture levels.
Partial Sun / Partial Shade: These terms are often used interchangeably and mean roughly 3 - 6 hours of sun each day. Morning or early afternoon sun is typically preferred by these plants.
A plant that has a partial shade requirement will need relief from intense late afternoon sun, either being shaded by a nearby tree or by being planted on the east side of a taller structure such as a building or fence.
Full Shade: No true plants can survive without light, but some have very minimal requirements. Full shade plants can make due with less than 3 hours of direct sunlight each day or with filtered sunlight for longer times through the day.
is the method used to manage the health and shape of a plant. Pruning is used to remove dead or unhealthy branches, to stop crossing of branches and, generally, to shape plants.
Pruning can assist the appearance and health of the tree; or, if done badly, can trigger disease and even kill the plant.
Branches that are too close to or touching others can be problematic. Cutting or removing one or both will open up space for air circulation and sunlight inside the tree or plant.
Dead branches allow disease to spread and should be removed. Diseased branches must be dealt with to keep the infected area from spreading to the rest of the plant or others nearby.
Branches typically need to be removed completely, or cut back to a much larger branch. Cuts should be made at the collar, the small wrinkled protrusion where one branch grows out of another. Smaller branches that need shortening are cut just beyond one of the yet smaller branches that angles out from the branch to be cut.
is the preferred method for starting many plants. However, given the relatively short growing season in Southern Alberta and the convenience of placing established plants quickly, often seeding indoors before transplanting or purchasing potted plants is the preferred alternative.
Many vegetables with short growing seasons can be started from seed after the last frost. Those with longer seasons can be started indoors and transplanted. See our Vegetable Planting Guide for more detailed information.
Most annual and perennial flowers, shrubs and trees are available at minimal cost, reducing the need to seed.
See our plant listings in the Plant Products section of our web site for specific varieties.