It’s necessary to plant bedding plants as soon as the danger of frost is past or when the soil warms sufficiently. In Colorado, planting is usually safe from about mid- to late May, depending on the types of plants and the area of the state. Consult with employees of local nursery or Garden centers for specifics on each variety.
Remember to read seed packets, catalogs and plant tags for the correct spacing between new plants. If planted more densely than recommended, bedding plants may not develop fully and may be more susceptible to insects and diseases because they are competing for air, water, nutrients and sunlight.
Prepare the soil for planting by adding a one-inch layer of organic material and till it in to a depth of six to eight inches. Inspect the seedlings and carefully remove them from the pots. The soil around the plant should be moist. If the plant is pot-bound, with roots encircling the outside of the soil, gently score the root ball on all sides with a sharp knife. Try to keep the root ball intact and make only shallow cuts. These cuts will encourage rooting.
Dig a small hole for the seedling. Place the plant deep enough in the soil to cover the top of the root ball with one-quarter of an inch of soil. If the top of the root ball is exposed, the plant will dry very quickly and could die. Move soil around the plant and firm the soil, but do not pack it down.
Water with a gentle spray to wet the entire area without puddling or eroding the soil around the transplants. Keep plants watered to develop healthy, large, leafy plants that have deep roots, can withstand the heat of summer and bloom or produce a bountiful harvest.
For “Organic soil amendments” refer to message number 1604.
For more information, see the following Colorado State Extension fact sheet(s).