UNITED STATES—Now that it is time for cool season annuals, it is difficult to remove warm season annuals if they are still blooming and healthy. that is probably why so many of us prefer mixed plantings, where cool season annuals can be added as needed to replace warm season annuals as they deteriorate. Some warm season annuals that are actually perennials, like wax begonia and busy Lizzie (impatiens), can be cut back and overplanted with cool season annuals, so that some might regenerate next spring as the cool season annuals finish. Petunias may be looking overgrown and tired, but are at least easier to remove without guilt.Pansies and smaller but closely related violas are probably the two most popular of cool season annuals. They work something like petunias, but for autumn and winter. They are commonly grown in uniform beds, but work just as well in mixed plantings.
The various primroses require a bit more effort because deteriorating flowers need to be removed. They can also be a problem for the few who are allergic to them (like poison oak). Like the warm season annuals that can survive as perennials through winter, some primroses can survive through summer as perennials.
Stock has an intense and distinctively rich fragrance. Taller types are excellent cut flowers, but are not so practical for uniform beds. Even shorter types are probably best in mixed plantings, or in borders with lower flowers in front.
Ornamental cabbage and kale are grown for bold rosettes of colorful pink, white or pink and white foliage. Cabbage provides more color. Kale has more variety of foliar texture. Ironically, both look rather weedy, and should be removed as they begin to bloom in spring.
Chrysanthemum are strikingly colorful cool season flowers, but rarely bloom as uniformly as they do when first planted. Because they bloom so profusely, they need to be groomed frequently. If they get what they want, they can perform for several years.
Sweet William, Iceland poppy, calendula and alyssum are also in season. Calendula is best through autumn, but may mildew by winter. Alyssum is white or subdued shades of pink or purple, and is actually good throughout the year.
The advantage of cyclamen, Cyclamen persicum, is nonconformity. Bloom begins in autumn when there are not many other flowers to provide color, and continues until spring. Cyclamen then defoliate and go dormant through summer while most other plants enjoy the warm weather. Even their red, pink, white, purple or salmon flowers are inside out, with petals flared back. The flowers can stand as high as six inches, just above the somewhat rubbery foliage. The rounded leaves are mostly dark green with silvery or gray marbling.
If used as annuals for one season, cyclamen are uniform enough for bedding. However, if later overplanted with warm season annuals and allowed to stay through summer dormancy, regeneration the following season is variable, with larger and smaller plants, and some that do not survive. As perennials, cyclamen therefore work best in mixed plantings, where variety is not a problem. Cyclamen should be planted with their tubers about halfway above the soil level, and should not be mulched. Soil should be rich and drain well.
By Tony Tomeo