06 April 2011

Purchasing Spring Plants

Last time we talked about starting your spring plants indoors. If it’s too much for you to consider, or you just don’t have the room, you can always visit your favorite local garden center to purchase plants for your garden in the spring. You should keep in mind a few points while making your choices.
Look for local growers as their plants will adapt more readily to your garden since they are grown here. There are many retailers who bring plants in for sale from out of the area, usually from areas where they have longer, earlier grower seasons. Because diseases and insects have specific life cycles, and because the growing season begins earlier in these other locations than here in the North, there is the strong possibility that plants from these regions can transport diseases and/or insects into the Northern zones, before their natural cycle would normally begin in our area. Such was the case with Late Blight just a short time ago in 2009.
Late blight is a fungus of which mainly tomatoes and potatoes are susceptible. It can also affect other vegetation within the same family (Solanaceae). The Late Blight we suffered in 2009 had been linked to plants that were brought in from a southern region supplier. It began earlier in the season than is normal for our area (it usually arrives after our tomato season has ended) and the excessive wet weather and humidity we had that season further exacerbated the problem, wiping out most family gardens and farmers’ tomato crops for miles around.
Many smaller, local garden centers and growers grow their own plants or purchase plants from other local growers. Develop relationships with the owners and staff. Learn where their plants are from if they are not growing their own. It’s always a great learning experience and many local growers and garden centers are happy to share that information.
Another important tip is to ask if the plants have been hardened off. This is the process of acclimating the plants to our outdoor climate prior to planting them in your garden. This is done by opening up the greenhouses and increasing air circulation while they are still protected in the greenhouse. They are allowed exposure to cooler temperatures in order to help lessen the transplant stress once they are placed outdoors. This step is vital to successful performance in the garden.
Also keep in mind the requirements your garden has for specific types of plants. Is it sunny, shady, or a combination of the two? Is the soil wet or does it have good drainage? Some varieties perform better under certain conditions than they do others. Do you have a need for trailing plants or plants with height? Knowing these specifics will help the staff at your local garden center to better be able to assist you with choosing the right plants.
Keeping these points in mind should better help you plan for and plant a successful garden.

Soil Fertility

Soil fertility is a key component in growing healthy plants.  There are many different factors which affect soil fertility and as a result, the soil makeup is constantly changing.   There are at least 16 nutrients which are necessary for plants to grow and complete their life cycles.  Of those 16, non-mineral elements are used in the largest amounts and are found in air and water.  Those non-minerals are carbon, hydrogen and oxygen.   Plants rely on the sun’s energy to convert carbon dioxide (carbon and oxygen) and water (hydrogen and oxygen) into food.  This process is known as photosynthesis.   The rest of the elements (minerals) are known as macro-nutrients and micro-nutrients and can be either found in the soil or added as fertilizer or lime. 
The 3 primary macro-nutrients are nitrogen (N), phosphorous (P) and potassium (K).   These are most commonly supplied as fertilizers and come in different ratios to accommodate different needs.  The three secondary macro-nutrients, calcium, sulfur and magnesium, are needed in smaller quantities than the primary nutrients.  Sulfur can usually be supplied through fertilizers and calcium and magnesium are usually present in lime and gypsum.  Lime and gypsum are typically used to effect changes in soil pH or as buffering agents to neutralize acidity. 
There are seven micronutrients; boron, copper, chlorine, iron, manganese, molybdenum and zinc.  While these nutrients are found in even smaller quantities, they are just as important to the functioning of plants as the primary and secondary nutrients.   Deficiencies in micronutrients affect plant growth, vigor and production.
Nutrients take different forms; liquids, solids or gases.  These elements react with each other differently and these reactions in turn, affect the absorption of the nutrients by the plants.  Plants utilize certain nutrients in certain forms, but to speak in detail about this now is well beyond the scope of this article.  Other factors affecting nutrient uptake include soil pH, microbial activity and the condition of the soil, such as aeration, temperature and moisture. 
Soil pH affects microbial activity, which is needed to convert nitrogen and sulfur into useable forms for the plants.   Using lime will raise the pH of the soil.  Ideally, soil pH should be 6.0–6.5.   At this pH, microbial activity increases and nutrients are more readily absorbed by the plants.  (If using artificial medium, i.e. peat moss, pH should be one point lower because there are no soil components to act as an exchange site for the elements.)
Soil type affects the absorption of nutrients by plants as well.  In general, the macro and micro nutrients are dissolved in water and taken up by the plants’ roots.  Soil type varies with the makeup, or texture, of the soil.  That is, the proportions in the soil of clay, silt, sand and organic matter.  Soils with higher amounts of sand have increased drainage.  This drainage causes a washing away, or leaching, of the nutrients in the soil, creating a lack of nutrients for the plants.   Ideal soil types would have equal proportions of clay, silt, sand and organic matter.
As you can see there are many factors affecting soil fertility.  It is very important to feed your plants on a regular basis.  Just as people need food, so do your plants.  With the proper nutrition, your plants will thrive and flourish.