Tips for planting a container garden: From the Ground Up with Linn County Master Gardeners

This is the time of year when gardeners want to dig in the dirt and be rewarded with flowers by the end of May. Due to the cool ground temperatures it is a bit early to plant annuals in the ground. But it's not too early to prep plant containers for patio, deck and outdoor table tops.

The first step in the process is to choose a container that has drainage holes. Outdoor containers receive rain amounts that are totally unpredictable. The smaller the container the more watering you will have to do in the event of a drought. An ideal container should be 12 inches or larger - sometimes the larger the better.

The next step is obtaining the proper soil. Never use soil from your garden. Soil from your garden will harden in the container and never be able to absorb water to nourish your plants through the hot summer months. Potting soil may be purchased ready to use or can be prepared yourself. If you choose to prepare it yourself you will need to use one-third peat, one-third compost and one-third vermiculite. Thoroughly mix these three ingredients and use as the soil for your containers. If you are doing several containers mixing in a large garbage can allows you to storage it for future use. Also make sure the soil is moist before planting.

If your container is more than 12 inches deep you may want to place a filler in the bottom of the container to reduce the amount of soil needed and the weight of the container should you desire to move it. The filler can be empty plastic bottles or Styrofoam peanuts. If using smaller objects such as Styrofoam peanuts, placing them in mesh bags before placing them in the container will make it easier to empty the container in the fall. It prevents the peanuts from getting into the environment and all over your yard.

The next step is to choose your plants. The old adage is choose 'a thriller, a filler and a spiller.” This means choose a tall plant for the center, a compact plant for the filler around the tall plant and a trailing plant for the edge of the pot to spill over the sides to soften the edge of the arrangement. The classic arrangement is a spike, geraniums and vinca. If you have limited space and enjoy having fresh vegetables, go ahead and combine vegetables in your container. Choose a robust patio tomato or a green pepper as your thriller. Plant carrots as your filler and surround it all with lobelia in an intense blue color. Have fun at your nursery or greenhouse choosing plants. Remember you are the artist in your container design.

l For questions, call the Linn County Extension Master Gardener Hortline at (319) 447-0647.