When to Plant: Most annuals need to be hardened off before planting. This just means that you set your new acquisitions outside during the day and bring them at night to toughen them up. Do this for at least a week to get them in shape for planting. Tender annuals shouldn’t be planted until after all danger of frost has passed and the soil is warm. Color-starved gardeners with enclosed back yards will push the envelope and will have planted on Mother’s Day. The prudent gardeners will wait. Our predicted last frost date is usually May 15th.
Where to Plant : Most annuals like at least 6 to 8 hours of sun a day. Some favorites are petunias, calibrachoas (similar to mini-petunias), zinnias, snapdragons, cosmos and geraniums. (While you are stocking up, don’t forget the dahlias! Dahlias come in an array of colors, shapes and sizes and are ideal as cut flowers in arrangements.) There are many annuals that will do well in part shade. These include ageratum, begonia, coleus, dianthus, fuschia, impatiens and lobelia. All will bring you repeating joy throughout the summer season. If you are putting these into your favorite pots, don’t forget to ‘recharge’ the soil. You can do this by simply adding a bit of compost and new potting soil to what is already there to freshen things up for the new inhabitants.
How to Plant : If you are like most gardeners, you want flowers and you want them now! Don’t bother separating the plants from your four or six packs, dig a big enough hole and put the entire group in together. This will give you the instant “WOW” that you have waited all winter for. Before planting, water your plants and the soil in your bed well. Remove the plants from their pots gently to disturb the roots as little as possible. (If they are in peat pots, tear the pots slightly to make it easy for the roots to grow through.) If the roots are compacted, loosen them gently before planting. Dig the hole slightly larger than the root balls, and set the plants at the same level that they were in the pot. (That is to say, don’t sink them too deeply or plant them on a hill.) Carefully firm the soil around the plants and water well after planting. Keep moist until the plants are established and new growth has started. Space your groupings to allow for air circulation and summer growth.
Finish off the process with a dose of slow release granular fertilizer (like Osmocote). Easy on green-dissolve-in-water fertilizers (like Miracle-Gro), as over use can cause a build-up of salts in the soil, especially here in Colorado.
What Next? 1) Water judiciously. This means you neither drowned nor starve them for water, but feel the soil before turning on the hose. 2) Deadhead the spent blooms by pinching them off to encourage more flowers. 3) Look around for more places to plant all the rest of the flowers you impulsively bought at the garden center….