No other bedding plants exhibit such rich blue as trailing lobelia, Lobelia erinus. Cultivars with white, purplish pink, purple or sky blue bloom are still not quite as popular as the favorite cobalt blue bloom. Individual flowers are tiny but very profuse and uniform. Some have white centers. The narrow leaves are tiny as well, and finely textured. Some cultivars have dark purplish bronzed foliage.
Individual plants are only about three to six inches high and wide. Cultivars that are more rounded and densely foliated are excellent for edging. They are very popularly planted in single rows, and alternating with alyssum. Trailing types exhibit wispier growth that stays a bit lower and spreads a bit wider. They do not trail far, but cascades nicely from urns and hanging pots of mixed annuals.
Although grown as a warm season annual, trailing lobelia can survive as a short term perennial where winters are mild. Fresh new growth develops out of the centers of overwintered plants about now. If pressed gently into the soil just before they are replaced by new growth, scraggly outer stems can develop roots. They just might grow into new plants before the originals eventually die off.
Angelonia is one of those warm season annuals that can actually survive through winter as a pernnial to bloom again next spring. It may even want to continue to bloom untill frost. The flowers can be blue, purple, red, pink or white, and look something like small snapdragon flowers. Most have spots or stripes of an alternate color or two in their throats. Some modern varieties have fragrant flowers. Plants can get a foot or two tall, and almost as wide. In sheltered spots, angelonia can be cut back as soon as it starts to look tired in autumn. Exposed plants might be happier if cut back significantly later, as winter ends. Old growth may be unsightly for a while, but can protect interior stems and roots from frost. Besides, pruning stimulates new growth that will be more susceptible to subsequent frost.
Actually, French marigold, Tagetes patula, is no more French than African marigold is African. All are from Mexico and Guatemala. They were merely popularized and bred respectively in France and Africa. There are now hundreds of varieties. Yet, their color range is surprisingly limited to hues and shades of yellow, orange and ruddy brown. White marigolds are really just very pale yellow.
Like gardenia, dogwood and snapdragon, the potentially finicky Madagascar periwinkle, Catharanthus roseus, is often challenging to grow. It enjoys, but seems to prefer more humidity than it gets here. The happiest plants can get nearly two feet tall and wide in sheltered and humid spots. (They can get even larger in exposed spots in humid climates.) Yet, most of us are satisfied with relatively scrawny plants less than half a foot tall.
A landscape designer would have more fun describing both the modern and the good old fashioned varieties of morning glory. Their vivid colors are so resplendent. Their rich green foliage is so luxuriant. Their delicate vines are so elegant. Hey, perhaps this is not so difficult. Anyway, the popular garden varieties of morning glory are descendents of various species of the genus Ipomea.
It is fair to say that garden verbena, Verbena X hybrida, is a reliable warm season annual. It gets planted in spring to spread out and bloom through summer with bright pink, red, purple or almost blue, or softer pastel pink or pale white. It is commonly replaced with cool season annuals by late autumn. However, garden verbena is actually a short term perennial that can survive winter to bloom for a few years.
The flowers may not last very long once cut, but cosmos, Cosmos bipinnatus, blooms so abundantly, that there might not be any shortage of new flower to cut and bring in to replace those cut a day or two before. Their pastel pinks and lavenders, as well as white, suit the Easter season perfectly. Their soft light green foliage is remarkably lacy. Mature plants are about two to four feet tall.
Pulling out cool season annuals that are still somewhat colorful is never easy, even if they are already deteriorating. There is always the desire to stretch their season as late as possible until they succumb to warmer weather. Only a few can perform all year, or get cut back to hide below other taller plants until the weather gets cool enough in autumn for them to regenerate and bloom again.
The same cooling weather that is initiating fall color is what finishes the zinnias that bloomed so colorfully through summer. Like tomatoes, they can stay out in the garden until they succumb frost if they continue to perform, and if the space they occupy is not needed for something else. There should be no guilt with replacing them sooner. After all, they are technically warm season annuals.
Tony Tomeo 