UNITED STATES—Warm season annuals that started late last winter should be finishing their season soon. It might seem as if they replaced their predecessors, cool season annuals, only recently. This is the nature of annual bedding plants. They perform only for their particular season. It is now about time for cool season annuals, or winter annuals, to begin another season.

There is no need to hurry, though. The several different cool season annuals operate on different schedules. Only the earliest begin as small plants now, and even they can wait. Some prefer to begin later during autumn. Cyclamen and ornamental kale can even wait until winter. Only annuals that start as seed really must do so while the weather is warm.

Besides, some warm season annuals still perform too nicely for immediate replacement. Ideally, they are only beginning to deteriorate as they relinquish their space. Sometimes, some varieties are already grungy before their replacement. This facilitates their removal without guilt. However, some warm season annuals might continue to perform until frost.

Transitions may be unpleasant.

Furthermore, some annuals, both cool season and warm season, are actually perennial. They merely function as annuals because their replacement is easier than their salvage. Busy Lizzie, for example, can remain mostly dormant through winter below new pansies. As the pansies finish in spring, the older busy Lizzie can regenerate for another season.

Sweet William and various primrose are cool season annuals that are actually perennial. Both can bloom until next spring becomes too warm for them. Then, they become mostly dormant until the following autumn. Any that remained dormant through last summer can regenerate and bloom this autumn. Perhaps they take turns performing with busy Lizzie.

Pansy and viola are the most familiar and reliable of cool season annuals. Marigold and snapdragon are popular now, but only as autumn annuals. They may not perform well for winter. Wax begonias might perform almost throughout the year with grooming after frost. Stock is the most fragrant of the cool season annuals. A few short varieties are available.

Highlight: Wax Begonia

Wax begonia, Begonia X semperflorenscultorum, exemplifies simplicity. Its floral color is white, pink or red. Its foliage is green, bronze or dark bronze. Each floral color combines with each foliar color for a total of only nine combinations. That must be enough, though. Variants of these nine simple options, including some with fluffier double bloom, are rare.

Wax begonia is most familiar as a common warm season annual. However, it is probably at least as popular as a cool season annual. Actually though, it is a short-term perennial. Except for during the coolest winter weather, established specimens may bloom all year. After minor frost damage, most regenerate efficiently. They need only minimal grooming.

Mature wax begonia should not grow any higher or wider than a foot. As bedding plants, they blend together. Individually, they develop densely ovoid form. Flowers are small but abundant. Foliage and stems are succulent, with a waxy sheen. New plants grow easily from cuttings or division. Wax begonia prefers rich medium and very consistent watering. A bit of partial shade should be no problem, but a bit too much can inhibit bloom.

Tony Tomeo can be contacted at tonytomeo.com .