Houseplants can be moved outdoors for the summer

Gradually move houseplants outside to protected areas when temperatures begin staying above 40 degrees. Prevent damage to the plants by gradually acclimating them to the sun and outdoor growing conditions.

Start by putting them in a shaded location outside on warmer days and bring them inside when nights are predicted to be cold. Increase the time outside and exposure to sun over a period of ten days or so.

Large houseplants in plastic pots should be slipped into larger, heavier pots to prevent them from falling over in the wind.

• Many trees are planted too deeply. To determine the proper planting depth for your new tree, locate the trunk flare — the place where the trunk widens at ground level. If the trunk flare is not showing, open the burlap and very carefully remove the excess soil above the roots to expose the flare.

You will need to plant the tree higher in the hole so the flare is just above ground level. Generally, planting 2 to 3 inches higher than ground level is a good idea in heavy clay soils.

It is best not to amend the backfill that will be returned to the planting hole, but it is OK to amend the soil at the surface around the tree.

• Plants that have been grown in containers should be moist when planted in your garden. When you remove the plant and its root ball from the container, spread out or cut all the roots that have encircled the root ball.

These roots have grown in a circle inside the container and could 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, as the lightweight container soil can dry out quickly and stress the plants. Generally, containerized plants need more frequent, but light, watering to get them established with roots into the garden soil.

• The containers you are going to use for seasonal plantings should have at least one bottom hole for drainage. A layer of gravel in the bottom of the container is not necessary.

Fill the container with a lightweight, fast-draining soilless mix — avoid heavy garden soil. Leave enough space between the top of the growing medium and the pot to make watering easy.

Very large containers can be partially filled with wood chips or empty plastic pots to conserve soilless mix. Separate the wood chips from the growing mix with landscape fabric.

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