There are several plants that will survive temperatures down to about 25 degrees F. So, when night temperatures no longer fall below that threshold, it is safe to plant violas, pansies, dianthus, calendulas, snapdragons and some primula and alyssum varieties. You can plant directly into the ground if it is not too wet. Test the soil by squeezing a handful. If it does not clump up, it is safe to work the soil.
If the ground is too wet, or you want color on the patio you can use these plants in containers. Another advantage of containers is the potential ability to get spring color even earlier. You can set the blooming containers out on days or nights when the temperature will be above 25 degrees and move them inside if the temperatures are predicted to fall below 25.
There are numerous colors to choose from for many plants that survive in cooler temperatures. Select the ones that seem most attractive to you. While all of these plants are considered annuals in most of the country, some, such as dianthus and violas may reseed and provide color for several seasons when planted in beds.
To ensure optimum plant vigor and color, mix Natural Start by GreenView All Purpose Plant Food into the beds as you prepare them for planting. You can also mix a small amount into the potting soil for your containers.