Planting in containers in cold climates

Cold-climate gardeners often become experts at growing plants in containers. These basic guidelines will get you started on keeping your blooms flourishing in containers during the chilly months.

While the summer show of container-grown annuals is always outstanding in the neighbourhoods of the north, comparable wonders take place indoors over the winter months, as smaller containers are called into service to hold bulbs forced into bloom on sunny window sills. These range from window boxes that hold huge cascades of petunias and other trailing plants to barrel halves brimming with nasturtiums and various other tender or hardy plants.

Tulip, hyacinth and daffodil bulbs sold in the fall are easy to grow in containers, and bulbs potted up in the fall will bloom in late winter or early spring, provided they are given a suitable regimen of temperature, water and light.

Hyacinths are especially endearing bulbs to force because of their intoxicating fragrance. Additionally, hyacinths have sturdy stems and are less prone to falling over than the long-stemmed tulips and daffodils usually grown in pots.

You can use any type of container for forcing bulbs, although tulips and large-flowered daffodils grow best when planted in deep pots, with at least eight centimetres (3 1/4 inches) of soil below the bulbs, and 10 centimetres (four inches) of soil over the bulbs.

However, it is possible to coax small daffodils and hyacinths into bloom by planting them in shallow dishes with a mixture of soil and pebbles tucked up to the necks of the bulbs, taking care not to cover the growing points of the bulbs. These bulbs are so forgiving that many gardeners use any containers they have on hand for forcing bulbs.

Later, when the plants are ready to be displayed in high-visibility spots indoors, the recycled planting pots can be temporarily slipped into more decorative brass or ceramic containers for display indoors while they are flowering.

1. For the first six weeks after planting any hardy spring flowering bulbs in containers, keep the soil barely moist, and store the planted containers in a cool place, such as a garage or unheated porch that stays above freezing, or put the pots into a plastic bag, seal the bag and store it in the refrigerator. Although you may see no signs of life from the bulbs, the roots are actively growing.
2. After six weeks, when shoots of green do appear, move the pots to a bright location, but keep them cool.
3. Continue to water the soil regularly, and enjoy the show as the leaves give way to dramatic flower spikes.
4. After the flowers fade, keep on watering until the foliage starts to die down.
5. Then stop watering and allow the bulbs to dry. They can be planted in the garden immediately or in the fall. They probably won't bloom the first year but will after that.