cOnTaInEr gArDeN

By Deb Courtner Colorado State University Extension Master Gardener in Larimer County

As warm weather approaches, it’s time to prepare for growing food and flowers. If you have limited yard space or just want to be able to move your plants to safety in a hail storm, growing plants in containers may be an attractive option

Plants — What can you grow in containers? Just about anything, as long as the pot size is adequate. If you’re into vegetables, you can grow tomatoes, eggplant, peppers, cucumbers, cabbage, beans, beets, carrots, scallions and leafy greens to name just a few. When selecting plants, look for those that have been developed for containers and/ or go by the names of “bush” or “determinate.” And, of course, you also can grow herbs, such as basil, sage, rosemary and mint.

As for flowers, most gardeners grow annuals (as opposed to perennials) in pots because annuals bloom all season long. If you have a hot, sunny area, good choices are lantana, Peruvian petunias (calibrachoa), pentas and geraniums. You can throw in some ornamental grasses, too. For shadier areas, possibilities include fuchsia, begonias, lobelia and impatiens.

Containers — You can grow plants in just about any container. Just make sure that the container didn’t contain toxic materials in the past, especially when growing edibles. Viable containers include clay pots, ceramic pots, plastic pots, buckets, storage bins and even plastic tote bags if they’ll stand upright.

If you select plastic containers for edibles, look for resin codes 1, 2, 4, and 5 on the bottom of the pot or bucket. Avoid 3, 6, and 7, which can be harmful.

Drainage is perhaps the most important component in keeping your potted plants alive. If drainage is inadequate, plant roots will rot. When choosing a container, make sure it has drainage holes. If it doesn’t, add some by using an awl, large nail or drill. With ceramic pots, be sure to use a masonry bit on your drill.

For more information, refer to Colorado State University Extension’s fact sheet #7.238 at extension.colostate.edu which offers additional details on selecting containers.

Potting mix — Use high-quality potting mix or soilless mix from a reputable nursery in your containers. Potting mix usually consists of or- ganic matter, peat moss and perlite. Some brands also contain a slowrelease fertilizer. If your potting mix doesn’t have added fertilizer, then mix a slow-release, granulated fertilizer into the media before planting.

Planting — Frequently when you buy plants, you’ll find that the roots are all tangled up from growing inside a small pot. Some plants may even have roots growing out the bottom of the pot.

If the plant is only slightly root-bound, simply fluff the roots by teasing them apart with your fingers. If, on the other hand, you’re dealing with a gnarly situation, unfurl roots at the bottom of the pot the best you can. If necessary, cut the roots to a workable length. If the root ball is packed solid, don’t be afraid to cut an inch or so off of the bottom of the root ball and make a few slices into the sides, as well. Once you’ve done that, begin your root fluffing.

The point of root fluffing is to enable the plant roots to grow out into the soil for nutrients rather than growing in on themselves. Once root fluffing is complete, insert the plant into your container potting mix, tamping down the potting mix slightly to eliminate air pockets.

Water the plant with a watering can until water runs out the bottom of the container. Watering will help the soil settle. If the potting mix level drops noticeably after watering, fill sunken areas with more potting mix.

For more details on container gardening, check out CSU Extension’s free webinar, Planting Container Flowers, at https://www.youtube.com/ watch?v=cfsyUeMEQiA.