August is a betwixt and between month when plants that flower profusely during early to midsummer have died down. And then the late summer flowering plants are only just starting to come into flower. Bad weather will also hold back flowers.

This is an ideal time to walk around the garden and assess what gaps are appearing in the borders.

Some of these gaps may just be temporary, due to late summer flowering plants not yet ‘doing their thing’. Other gaps may be more permanent. This may highlight an area where current plants haven’t bulked up to fill the space, or where plants may have died.

Tall plants in pots

Agapanthus

Some tall plants like agapanthus grow well in pots and, therefore, make great temporary fillers to plug border gaps.

Agapanthus flower colours range from pure white to different shades of blue and dark purple.

The beauty of agapanthus is that they produce their flowers on tall, sturdy stems. These are mainly unaffected by strong winds or heavy rain.

Ornamental grasses are also excellent pot-grown choices. Especially as, at this time of the year, many start to produce long elegant flowering plumes. They nod gracefully in the breeze creating a softness and delightful sense of movement in the border.

Miscanthus ‘Morning Light’ has elegant, narrow, arching silver-grey leaves with pink-tinged and white flowers in the autumn.

Pheasant tail grass (Anemanthele lessoniana) is another gracefully arching grass but with a difference. The narrow leaves turn delightful shades of red and orange during the autumn and winter months.

Calamagrostis x acutiflora ‘Karl Foerster’ has an upright habit and will also look good throughout winter whilst also providing seeds for birds.

Miscanthus morning light tall plant for gaps
Pheasants tail grass
Calamagrostis x acutiflora 'karl foerster'

For guaranteed year-round presence fastigiate yew (Taxus baccata fastigata) and Italian cypress (Cupressus sempervirens) can both be grown in pots.

Plus, their naturally thin upright habit means they won’t intrude too much in the space or cast any appreciable shadows.

Tall cypress trees growing in containers

Tall plants for permanent planting

Some roses will grow tall and wide without needing support and start to repeat flower at this time of year. Plus they produce rather handsome hips in the autumn.

Rosa ‘Lady of Shallot’ is a wonderful choice if you like large, orange, scented flowers and orange hips. It will continue flowering right up to the first frosts as will  R.  x odorata mutabilis. This rose has smaller, single, scented flowers which enchant as they change colour from pink to orange to honey-yellow.

For masses of larger, soft pink flowers on thornless stems try R. ‘Mary Delaney’.

Rosa 'Lady of Shallott'
Rosa x odorata 'Mutabilis'
Rosa

With enough space and love for a cottage style, hollyhocks are perfect, with statuesque flowers towering above most other flowers.

Just give them plenty of space for air to circulate as, if too crowded, they can develop rust.

Hedychium

Mention the word ‘ginger’ and we usually think of ginger root bought at the markets and supermarkets. However, there is an autumn-flowering ginger plant that produces tall spikes of beautiful, orange-red flowers.

Hedychium ‘Tara’ has lance-shaped leaves in addition to the lovely scented bright colour flowers. And, at two metres height when in flower, they are sure to make an impact.

It will need protecting overwinter with a layer of mulch to ensure repeated flowering the following year.

A hardy, tall, airy perennial which reliably grows and flowers every year is the beautiful perennial sunflower (Helianthus ‘Lemon Queen’). Their stout stems support many side stems loaded with masses of pretty, pale lemon daisy flowers for weeks on end.

Sunflower 'Lemon Queen'

By filling in any empty spots in the garden, your borders will look lush and lively all summer long.

Plants for Summer Containers:

Or check out my Pinterest board for more ideas: