By Amy Woodward, Master Gardener

Throughout the years annuals have been a staple to grow in containers.  However, they can be high maintenance and expensive as they are discarded after a season of planting.  Growing perennials in containers has started to become popular.  Perennials require less maintenance and are expensive initially but are a great investment as they continue to grow year after year.  Advantages of growing Perennials in Containers:

• Great way to have perennials if you don’t have a lot of space
• Fast spreading perennials can be contained
• Mobility- you can move your plants to suit your needs
• Weeding is eliminated and less deadheading
• You can adjust your soil PH easily depending upon the perennial you are planting
• Perennials can be planted before annuals as they can handle the cooler temperatures

Choosing Plants and Containers:

• Use plants that have similar requirements for sun, feeding and moisture.  Plants in containers will need more watering than those in the garden, as the plants can’t draw nutrients and moisture from the soil.
• Use “thrillers, fillers and spillers”.  The tallest plants are the thrillers and they go in the middle of the pot.  Fillers are medium sized and go around the thriller plant. Spillers trail over the sides of the pot.
• If you do not plan to overwinter the perennials then make sure you choose plants that are 2 zones hardier
• Use larger pots as plants become root bound and are quick to dry out
• Make sure your pot has been cleaned before use and has good drainage
• Choose a container that does not dry out quickly or freeze

Examples of perennials to choose:

Achillea, Echinacea, Aster, Heuchera, Astilbe, Hosta, Bergenia, Lamium, Bleeding Heart, Phlox, Coreopsis, Sedum

Options for Overwintering Perennials

In colder climates, perennials cannot be left outside in containers over the winter. Remember plants that are hardy in the ground may not last in a container.  When you chose perennials you must consider the zone.  If you choose to leave in a container over the winter the rule of thumb is to choose plants that are 2 zones hardier.  Here are some other options to overwinter perennials:

1. Move plants in containers to an unheated garage. Do not fertilize when the plants are dormant.  Once plants stop growing in the fall, stop fertilizing.  Plants will need to be watered until the soil is frozen.  When temperatures increase in late winter or early spring gradually move containers back outdoors.
2. Transplant into the garden.  Then dig them up in the spring and return to the containers.
3. Bury the pots in the ground.  The roots will then be better insulated.  In the fall, dig a hole in the ground that is large enough for the container.  Place the container in the hole then cover with leaves or mulch.  In the spring, bring the pot out of the ground.