Spring fever for planting

After a few weeks of mild weather, spring-hungry Chicagoans think about planting.

Container tips

Containers for seasonal plants should have at least one hole at the bottom for drainage. A layer of gravel in the bottom of the container is not necessary to improve drainage.

Fill the container with a lightweight, fast-draining soilless mix and avoid using heavy garden soil even if you amend it with compost.

Leave enough space (a half to 1 inch) between the top of the growing medium and the lip of the pot to make watering easy.

Very large containers can be partially filled with wood chips, plastic bags filled with packing peanuts or empty plastic pots turned upside down (which is my favorite method) to conserve soilless mix. Separate the wood chips from the growing mix with landscape fabric.

In-ground plantings

Plants that have been grown in containers should be moist when you plant them outdoors.

When you remove a plant and its root ball from a container, spread out or cut all the roots that have encircled the root ball. Roots that grow in a circle inside the container might eventually girdle or choke the plant if not redirected to grow out and away from the plant. This will help the new plant get established in the ground more quickly.

Monitor watering needs carefully after planting, because lightweight container soil can dry out quickly and stress the plants. Generally, container-started plants need more frequent light watering to get them established so their roots grow out into the soil.

Vegetable plantings

If you are growing vegetables, be sure to rotate crops to help prevent pest and disease problems. This is the easiest way to practice organic, integrated pest management gardening.

Many insects and diseases attack vegetables within the same plant family. By planting vegetables from a different family in a problem area, you minimize the chances for a repeat infection.

Plant families include the cabbage family (broccoli, cabbage, cauliflower, Brussels sprouts, radishes, and turnips); cucumber family (gourds, melons, squashes and cucumbers); nightshade family (eggplant, potatoes, tomatoes and peppers); goosefoot family (spinach and beets); onion family (leeks, garlic and onions); legume family (all peas and beans), and the carrot, celery and parsnip group.

• Tim Johnson is director of horticulture at Chicago Botanic Garden, chicagobotanic.org.