CONTAINER GROWING

The nursery industry has converted a large percentage of their field production into container production in the last 10 years. Container grown trees or shrubs have a longer shipping season from April to November rather than a restricted period in early spring and late fall for bare root. The greatest benefit from container trees or shrubs is the limited transplant shock when planted in a landscape environment. Since no roots are loss in the transplanting stage the plant keeps on performing with proper watering and soil fertility.

Growing in containers requires a higher level of management compared to field production. The grower must be aware of media composition, fertility level and quality of irrigation water. Most media in the Prairie consists of a raw peat moss, some coarse material such as compost wood chip or pine bark, sand and natural soil. The exact recipe of a media will depend on availability of these components. The watering practices of a grower –wet or dry will also influence the media composition.. Incorporating coarse material will have a tendency to create macro pores in the media, which will drain readily while component such as sand and soil create micro pores therefore holding to the water for longer period of time.

Since most water supply in the Prairie have a high pH(8.0) the media  pH should be 5.5 to 6.0. The water pH with time will equalize the media pH. If the pH of the media reaches 8.0 then some nutrients are no longer available to the plant therefore reducing growth.

Daily watering is required under hot summer conditions when the temperature reaches 28C or higher. In large scale container production irrigation system are activated 7 days a week during June throughout mid September.

With new technology in fertilizer formulation now the grower can control the fertility level to optimize plant growth. Most formulation will last for 4-5 months or longer. N P K- ration varies but a normal ratio is 22-3-8 whereby the N will have a burst of release at the begin then stabilized throughout the season.

To winterize container grown plants the grower must ensure that the root system never experience temperature colder than –10 C or winter kill will occur. Some growers bring the container plants in an insulated building for the winter. Depending on the production scale this technique may not be practical therefore most growers lay down the containers then covered with poly and applies a generous layer of flax straw. Snow remain the best insulator and any growers enjoys winter when the container piles are covered with deep layer of snow.

For the homeowner, container grown trees or shrubs should mean greater success at transplanting time. After removing the container, the plant should be transplanted in a moist or freshly water soil. The watering regime after transplanting is directly related to the temperature. Under hot summer conditions the tree or shrub should be watered two to three times weekly for the next two weeks if the location is open. -Under shaded location then skip a watering. For spring or fall conditions then a generous weekly watering  should meet plant requirements. Always keep an eye on your plant to check for wilting or change in the intensity of the color of the foliage since this is the only way the plant can communicate with you.