By Kathi Thistlethwaite, Colorado Master Gardener

FALL…nature’s breathtaking display. Transitioning containers from summer to fall is easy, fun, and can be done with minimal expense. Begin by discarding spent annuals. Leave spikes, tall grasses, and spillers like vinca vine or sweet potato vine. Replace the annuals with any of the fall blooms suggested below and add a little fresh potting soil. Give the container a good watering. Use pumpkins and gourds to build on the fall theme and add color.

Fall Flowers that Work Well in Containers:

• Asters
• Celosia
• Croton
• Dianthus
• Mums
• Ornamental Kale or Cabbage
• Ornamental Peppers
• Pansies
• Rudbeckia
• Viola

Now that annual containers are dressed in their fall glory, it’s time to consider overwintering containers with perennials. Large wooden or concrete planters can usually be left in place. It’s best not to leave clay, ceramic or glazed pottery exposed to the elements to avoid cracking. If they must be left out, wrap them in bubble wrap or some insulating material covered with plastic to help with protection. Check soil moisture periodically in warm, dry periods during winter months. In the spring, remove the protective covers gradually to give the plants time to reacclimate.

Smaller containers can be buried in the ground and covered with soil or mulch, which acts as insulation. Water the plants well before the soil freezes. Potted evergreen plants will also benefit if they are screened to protect them from the wind. Smaller containers can also be moved to an unheated garage or basement. Check the soil moisture periodically, but don’t overwater or root rot may develop.

If empty containers have accumulated, fall is a great time to clean and prepare them for next year. Examine for cracks and take stock of what needs to be replaced or added. Consider taking advantage of the sale prices on pottery available at many garden centers this time of year. Remove debris and leftover soil from the empties and clean with a solution of 10-parts water to 1-part bleach. This process destroys disease-carrying organisms that could harm next year’s plantings.

For a more complete discussion of container gardening, see CSU Fact Sheet 7.238. Bon Jardinage!