UNITED STATES—Just like warm season vegetable plants in the vegetable garden, flowering warm season annuals get replaced this time of year. Although the weather is still warm, cool season annuals should be planted now so they can disperse roots before the weather gets too much cooler. Except for a few short term annuals and perennials, most should perform until the weather gets warm next spring.
Pansy, viola, Iceland poppy, sweet William, calendula, stock and the various primroses should get down to the business of blooming rather efficiently, and hopefully compensate for the removal of deteriorating warm season annuals. Ornamental cabbage and kale, as well as cyclamen, can be a bit later because they are a bit more sensitive to warmth, but not slowed much by cool weather.
Nasturtium and alyssum can work as either or both warm and cool season annuals. Both are annuals, so individual plants do not last more than a few months. In hot spots, they may perform well in winter, but then get roasted in summer. In cold spots, they may do exactly the opposite. In the right situations, they self sow and bloom all year. Tired old plants should be groomed out if unsightly.
Chrysanthemums are the most prominent of seasonal color for autumn, and come in all sorts of colors that are ideal for an autumn palette. They are actually perennials that are grown as annuals. Unfortunately, they are usually grown as very short term annuals, that are allowed to bloom only once, and then replaced with something more wintry, like cyclamen or ornamental cabbage or kale.
Like cool season vegetable plants, most flowering cool season annuals should be planted as small plants in cell packs. Chrysanthemum, as well as cyclamen and ornamental cabbage and kale that get planted afterward, are the exceptions that should be planted as four inch potted plants, but they are expensive anyway. Primroses can be planted from either cell packs or four inch pots. (Primroses can cause a serious skin allergy, just from contact.) Nasturtium and alyssum should be grown from seed sown early.
Highlight: society garlic
Some flowers are better left in the garden rather than cut and brought in. Society garlic, Tulbaghia violacea, looks like it would be an ideal cut flower, with nice bare stems. The aroma suggests otherwise. It smells something like a strongly aromatic combination of onion and garlic. Even in the garden, it might be a good idea to keep it at a distance. Deer and rabbits do not mess with it.
Society garlic is sometimes known as pink agapanthus because it has similar foliage and flowers, only much smaller. The tiny flowers are really more lavender pink than pink, and bloom in round clusters on stems about a foot and a half tall in late summer or early autumn. The narrow leaves are only about a quarter of an inch wide, almost grassy, but more rubbery like those of agapanthus.
Mature plants form dense clumps of foliage at least two feet wide. Variegated plants stay much smaller, but are also very likely to revert to green (non-variegated) growth, which if not removed, overwhelms and replaced variegated growth. Society garlic is very easy to divide for propagation. It likes full sun or slight shade. Although somewhat drought tolerant, it prefers regular watering.
Horticulturist Tony Tomeo can be contacted at tonytomeo.wordpress.com.