Early - Bloomers for the Garden

If you are like me, you are hoping that spring may be lurking just around the corner. Soon the forsythia and hellebores will start to bloom, and spring bulbs shortly thereafter. Early spring is an ideal time to plant hardy annuals for glorious early spring flowers.

There are many annuals that can be planted early and that do fine through spring frosts. Pansies are among the earliest flowers to bloom, and many have started to bloom throughout the Missouri Botanical Garden in more protected locations. Pansies are tough plants that are cold tolerant and able to survive outdoors during most temperature extremes in mid-Missouri. I purchased a flat of pansies one year during late March. I left the flat outside during a period in which our nighttime temperatures dipped below 10 degrees F several consecutive nights. Many days later, as I pulled the pansies out of the flat, it was just like pulling ice cubes out of a tray; they were completely frozen. I just stuck the frozen cubes into the ground wherever I could. Within one week, they were growing wonderfully and bloomed within a couple of weeks. Pansies are cool weather plants and prefer nighttime temperatures of 50 degrees and daytime temperatures around 60 degrees; thus, they are ideal for March planting and are a terrific complement to bulbs before perennials start blooming. Getting pansies started in the summer is difficult since they prefer cooler weather, so fall and/or early spring are ideal times to plant pansies. Once daytime temperatures start hovering over 75 degrees, pansies start to die out, and it is time to remove them and plant summer material. Pansies work well planted into flower beds with well-drained soil and are wonderful grown in containers. Plants can be rejuvenated by cutting them back which will also result in a new flush of blooms.

Similar to pansies preference of cooler daytime temperatures, Osteospermum (Cape Daisy) is a great annual to plant for early season color. They start to bloom with daytime temperatures of 50 degrees F but slow down when summer temperatures start to rise.

Another annual that thrives on early planting and can take relatively heavy frosts is the snapdragon. They can be sowed early in the spring once the ground is workable, but are more showy if you give them a head start indoors and place young seedlings into the ground. Snapdragons, like pansies, can be seeded outdoors in the fall and will survive through the milder Missouri winters, and bloom profusely in the spring. Snapdragons are like the other cold hardier annuals in that they tend to stop blooming and die out in the warmer summer months. However, recent breeding efforts have focused on more heat tolerant varieties and many of these are now available.

There are several perennials that bloom early. By late April into May, most bearded iris have begun to bloom with the dwarf varieties being the first. Two wonderful woodland native plants that bloom very early are Virginia bluebells and bloodroot. Other native perennials that bloom soon after are wild ginger, marsh marigold, woodland phlox, celandine poppy and hepatica. Bleeding heart and lungwort are also early bloomers that are ideal in heavy shade conditions.

March is also a perfect time to start thinking about spring cleaning in the garden. Spring garden clean-up should be done before plant growth begins, usually mid-March in central Missouri is ideal. It is best not to have a lot of new growth in the way while you are trying to clean-up the old stems and leaves. Raking leaves out of the perennial beds is best done in early March before bulbs begin blooming to minimize damage to the spring flowering bulbs as the new flowers are starting to emerge. As we start our spring cleanup in the garden, it is important to keep in mind that the Missouri weather extremes can still present a challenge to newly growing plants. Any thoughts of purchasing perennials are best not acted upon yet, as most perennials are not hardened off enough to plant into the garden.

Early spring is also a good time to divide most perennials before spring growth begins. The general rule of thumb on dividing perennials is to divide spring bloomers in the fall and fall bloomers in the spring. Spring weather promotes good shoot and root growth in the newly separated plants which then have a full growing season to become established. Most herbaceous perennials form a crown and can be easily divided. A crown forms over a period of years and increases the diameter of the plant. Dividing plants can be very beneficial when the crown gets crowded which results in less flowering and less vigorous plants. Asters and mums are examples of two perennials that should be divided on an annual basis. Dividing perennials also serves the purpose of increasing your plant stock.

Mary Kroening, Missouri Master Gardener Coordinator and UMC Horticulturalist (573) 882-9633