Black-eyed Susan, sunflowers and a few of the late warm season annuals and perennials are still blooming, and a few will continue into autumn. By that time, cool season annuals can move in; and some of the deciduous trees, shrubs and vines that turn color for autumn will be doing so. Realistically though, this can be the leanest time of year for color in the garden. Even some of the foliage that is colorful through spring and summer has faded.
There are certainly plenty of flowers in season now. However, not many are colorful. Honeysuckle vine is pleasantly fragrant as it bloom in random phases until the weather gets cooler, but the flowers are only pale yellowish white. Some melaleuca trees bloom profusely enough to make a mess, but are just as pale, and do not even provide fragrance; although some have pretty light pink flowers. Abelia flowers are pink and abundant, but are really not all that flashy against their bronzy foliage.
Some of the more colorful flowers are not quite as reliable. Princess flower, hibiscus, blue hibiscus and mandevilla certainly can bloom in late summer or autumn, but sometimes bloom earlier than expected, so have nothing left for later. The bright red flowers of blood red trumpet vine are quite impressive, but only if they are not obscured by the accompanying foliage. Some roses bloom in phases as late as the weather will allow, but actually, most are done by now.
Fuchsia and angel’s trumpet likewise bloom in a few phases once they get started, but unlike the many cultivars of roses, they are much more reliable for a late bloom phase. Escallonia blooms late with small but colorful flowers, but only if they have not been shorn in the past few months. Shearing deprives them of the blooming stem tips that they had worked most of the year for.
Butterfly bush, tree mallow, cape plumbago, bee balm and several varieties of sage and salvia are among the most reliable plants for late summer or autumn bloom. Even without multiple bloom phases, they just naturally bloom at the end of their growing season, before winter dormancy.