Container Cleanup

It's late winter, and in a couple of months, it will be time to start planting containers for the upcoming warm season. But first, the pots containing the remnants of last year's plants need to be cleaned so they'll be ready to go at the beginning of the season. Here's how to proceed:

Remove annuals, tropicals and other cold-sensitive, pot-bound plants from small- to medium-sized containers – top growth, roots, potting mix and all. Larger containers hold a fair amount of potting mix, so rather than remove the entire contents of the container, dig out the plants and you'll be able to salvage at least half of the potting mix. Use a soil knife or similar tool to cut through thick roots. Lift the top growth and root ball out of the container, leaving the bulk of the potting mix intact. Add fresh potting mix to fill up the rest of the container when replanting in spring. By doing this, you can cut the cost of potting mix in half.

Note: Use thick, sturdy gloves when handling cacti and succulents, Even though the top growth of the plants has turned soft and mushy, the needles are still stout and pose potentially prickly problems.

With perennials in containers, you can deal with them in a couple of different ways. One method is to simply trim the top growth and wait for them to send up new growth as spring approaches. When cutting back the top growth, take care not to damage the crown of the plant. The other method is to actually remove the perennials from their containers and plant them in the ground. In some cases, perennials that have been left in pots over the winter may not come back, even though they're considered hardy in your area. The reason for this is that hardiness ratings refer to plants grown in the ground, where their roots are fully insulated. The roots of plants grown in containers aren't as well insulated.

If you have a mixed container with both annuals and perennials, remove the annuals from the pot, taking care not to disturb the roots of the perennials too much, and place the dead plant material in the compost pile. Leave the perennials in the container but tidy up the plants by removing dead leaves and cutting them back.

With evergreens in containers, inspect the plants from all sides. Prune away dead or dying branches and rotate containers so that all sides of the plants receive equal amounts of sun exposure. If the evergreens have outgrown their pots, transplant to larger containers or directly in the ground. In most parts of the country, transplanting evergreens can be done either early in the fall or in late winter.

Once you have finished cleaning out your containers, put the plant remains and potting mix to good use. Chop it all up with a machete and dump it into the compost pile. Then turn the compost pile with a pitchfork. To properly cook a compost pile, it needs oxygen and moisture, so even in the winter it's a good idea to check the moisture content of the pile. Add a little water when necessary.

If your plants suffered visible damage last year from fungal diseases, including mildew, black spots or rust on leaf surfaces, scrub the now-empty pots and disinfect them with a solution containing one part bleach and nine parts water. However, if the plants didn't show signs of disease, you can simply scrub the pots with a brush and skip the disinfecting process. Once your containers are cleaned, you are ready for a new season of container gardening.