My garden looked so much better after a good hack. I chopped my geums back and my anthemis daisies that have been amazing I since I planted then 2 years ago. I cut my Euonymus Wulfini bracs that had lost their appeal to the ground leaving fresh steely foliage. Any centranthus or tired self-seeded feverfew. Do not overlook chopping your spring flowering shrubs particularly philadelphus which may turn into small tree if you are not careful. Hack it all back let it breath again. Your chopping may vary from year to year as in 2019 heat wave some perennials, I found were prematurely too tall and I cut the back early and may still be flourishing this year.
After giving your garden a late summer haircut removing finished blooms If you have not time to indulge and want instant colour, plant up some pots of strong dahlias or bedding and slip them in amongst the border. There is nothing wrong with cheating. However, there is a superb array of perennials that could be planted into the border often forgotten because so much garden shopping is done in the flush of sunny spring at Easter and around Mother’s day when these perennial look less inspiring. Generally we do not plan our flowers far enough into the year, we are so focused on summer forgetting its only one of four seasons.
|My border of asters|
Clear the Decks
Once you have removed all the scruffy growth and shaped your early flowering shrubs you have a new clean canvas to play with. If you are cleaver you will have chosen some sensible perennial bones that will be colourful for an exceptionally long season so there is still something interesting happening! I am thinking of cranes bill geraniums and euphorbia foliage, stipia grasses, evergreen ferns in the shade and so forth. On the long flowering front, I have great praise for my blue Geranium Rozanne and the smaller Azure Rush which are blooming away and my neat dainty pink Geranium Mavis Simpsons edging my pinkie purple border. I have planted all these repetatively not one plant alone that disappears visually amongst the competition. I llike to repeat plant.
Plant a Variety of Shapes Textures, heights and Colours
I love the shapes and textures in the borders not just the flowers. Lolly pop standard evergreens, topiary shapes, tall protruding columns of verbascum or phlomis and spikey foliage in perennials like Sysirincium stop the space looking bland. It needs ups and downs, a variety of shapes and it needs the right colours in the right place. Bright colours in sun but not in shade, paler colours in shade and White and yellow will wake up a border like a shaft of light. Combining grasses amongst late summer perennial can look gorgeous
What Perennials Flower in Late Summer and Autumn
Let me make some suggestions.
Asters (frikatii pictured above)
I always start with asters. Personally, I would make it illegal not to include asters in your border because they bring so much colour when the garden could if left begins to dwindle. I have a few different varieties but my most planted is the deep blue Aster Frikatii. Some asters have now been re-named under the genus Symphyotrichum whilst still in the same plant family and it is confusing. This season we have the Italian aster Aster amellus King George (blue) and Rosa Erfulling which is described as having flowers the colour of crushed strawberries! We also have aster drumundii (Symphyotrichum) with a slightly hairy leaf and aster laterifolius Coombe Fishacre which is also now a Symphyotrichum. Its soft pink with a more branching bush like habit with a mass of tiny flowers. All of them in the Asteraceae family and great from now into October.
|Helenium Moerheim Beauty|
More in The Daisy Family
Continuing with the Asteraceae family we love our rudbeckia, echinacea, helenium and leucanthemum.
|Echinacea Cheynne Spirit (orange and yellow together on one plant)|
Plant away as there are some great rich colours, though white and yellow in the case of the shasta daisies (below). This year in addition to the taller yellow varieties of Dreamii, Goldstrum and Autumn Colours we have dwarf rudbeckia (Little Gold Star) also on the beds, masses of variety in the heleniums lots of rusty colours in the Sundae series (Strawberry, peach and lemon and more!) and good old Moerheim Beauty the old time favourite.
|Leucanthmum Broadway Lights|
Madonna and Freak are also shorter stems so you can grow clumps at the front of the border. Freak has a slightly ruffled feather appearance and Madonna is a classic daisy head. Broadway lights is a tall glowing lemony yellow.
|Wonderful Wampee |
If you have enough daisies in the border than you want a different shape. The flat head of a tall achillia. New in we have a pink millefolium Tutti Frutti ‘Wonderful Wampee’ this could look soft and pretty with the right combination of tones alernatively the bold Summer Wine in burgundy will look very striking.
The most popular of all perennials is Verbena Bodnariensis. It is one of the most sold for the very reason it is a unique tall cloud of purple at eye level. A haze of rich colour sits above your border. Rigida and Lollipop are similar but much shorter mid border varieties and now we have Brampton the one we are beginning to love. It has rich purple foliage which is a rarity. This is foliage that colours the border even when not in flower. This is a mid border plant again. I have over wintered it in pots, and it is thriving and now covered in a profusion of pink flowers.
The penstemons are big performers and they are certainly beautiful. Treat these more like a little shrub and wait to trim the back when you see new shots late spring. They have a clump forming habit with strong colours on tubular flowers almost like foxgloves but with a very different habit. They come in every colour from deep red, purple to the classic Wedding Day white. Do not crowd them, give them room to breathe and they will perform well. They look lovely planted under and around new English roses.
If you want a plant that can fight its corner choose persicaria. In the past I have described it as a thug but a useful thug. Referred to often as super bum this seems to crack on everywhere, I put it in my heavy clay soil. It is in the knotweed family which explains its strength. Pale pink deep rose pink to red. Low growing or mid hight take your pick. I have it in a hot position and a partial shady spot. Varieties on the beds are Dajeeling, in both pale pink and red, amplexicaulis White Easfield and Red Dragon.
|Agastash Blue Fortune|
This is a late summer delight for the wildlife. It is in the mint family and the leaves have a very fresh aroma. Tall candles of blue flowers bring a new architectural silhouette into the border.
|Erynignium Blue Hobbit|
Thistly heads of tall steely eryngiums can stand a prickly mid height in the border or alternatively echinops heads all providing a cool frosted blue contrast.
These are perhaps one of the first perennials we think of when looking for later colour. They will grow in sun and partial shade most to about 75cm. They tend to look after themselves and give you a lot of flower from August to October. I can see at least 10 varieties on the nursery beds including the classics like September Charm (pink) and Honorine Jobet (white.) Once established they are really easy.
|Sedum Autumn Joy|
These are an absolute late summer winner. The succulent stem produces a vast plate of flower buds which eventually die well as hydrangea often do and still look attractive over winter particularly coated in frost. Sedums are loved by butterflies and bees. There are so many to choose from spectablis Autumn Joy, Vera Jameson and Touchdown Teak are just some of the varieties here.