Theme plants dominate the garden in their season. Through repetition of a common characteristic such as colour, form or by planting different variations of the same plant species a garden theme can be created. In the garden a seasonal theme might be confined to just one area, but can also be spread throughout the whole space. The challenge these repetitions create is that the available space to accommodate these plants is quickly used up — two or three themes per garden area is probably the most that can be achieved. An example of this might be a bold display of Narcissus daffodils in spring, followed by a cottage mix of Aquilegias, Astrantias and Geraniums with roses in early summer and then a prairie theme of bold yellow rudbeckias, heleniums, asters and grasses in late summer.
The theme for my autumn garden is asters amidst the many ornamental grasses growing there. Here Miscanthus sinensis ‘Kleine Fontäne’ brings focus to this mix of low-to-medium-height growing asters.
Aster ‘Johan’ is repeated throughout; its compact form and bold semi-double flowers filling the foreground here. The bright leaved shrub on the left is Spirea thunbergii ‘Ogon’.
White flowered Aster glehnii ‘Agleni’ is the tallest aster I have ever grown and it stands up easily with perhaps here and there a light support. Established plants may grow taller than head height; this is a young two year old cutting. Aster ‘Treffpunkt’ in the foreground is one of my most frequently used cultivars. The flower colour is a clear violet blue, it has a neat habit with narrow leaves and never needs staking.
This dry sunny border edge contains many different asters that trial and error has taught me can cope with less than ideal growing conditions.
Bold clumps of ornamental grasses lead the eye through the garden, asters create the colour theme and here annual Zinnias explode in early autumn following a mid-summer sowing — directly into the garden soil. Such fast growing annuals are an area of gardening worth exploring as they can bring something extra and unexpected to the garden so late in the year.
See also planting partners post.