18 long flowering plants that bloom from summer until the first frost
Long flowering plants mean that you can extend your summer colour right through to autumn. And even to the first frosts of winter.
Quentin Stark, head gardener at Hole Park Gardens in Kent, was asked to re-design the garden’s Centenary Gardens. He was given the brief ‘a bowl of colour’ for spring, summer and autumn. Some of the plants he chose even flower until the first frosts.
So I visited Hole Park Gardens to see his best late season long flowerers. The gardens are a stunning mix of more formal gardens and borders, such as the Sunk Garden and the Centenary Garden with wilder areas and sweeping park vistas.
Hole Park is open to the public from April to October, so the borders need to continuously look good. And long-flowering plants also support pollinators by providing nectar and pollen for a long period.
Long flowering plants in the Hole Park Centenary Borders. The top grouping features Helenium ‘September Fox’, Penstemon ‘Garnet’ and Kniphofia ‘Thompsonii’. The photo below it features the long-flowering annual Cleome (Spiderflower)
Late season long flowering plants for a ‘bowl of colour’
Quentin took me round the Centenary Garden, pointing out the longest-flowering plants for late summer, autumn and into winter. Some start flowering in mid-summer and go onto autumn. Others start in late summer and will take you to the first frosts. They are:
- Agastache
- Achillea (Yarrow)
- Diascia (Twinspur)
- Chrysanthemums (the latest flowering plant in the border)
- Gaura (now Oenethera)
- Helenium ‘September Fox’ (dead-head regularly for two months of flowers0
- Hummingbird Plant (Dicliptera suberecta)
- Japanese aster (Kalimeris incisa)
- Kniphofia ‘Thompsonii’ (an exceptionally long flowering kniphofia)
- Penstemons
- Persicaria (many species)
- Roses – (species vary – Rambling Rosie is a good long-flowering climber)
- Rudbeckia
- Salvias (species vary – ‘Greggii’ and ‘Microphylla’ salvias are the longest flowering)
- Sedum/stonecrop (now Hylotelephium)
- Society Garlic (Tulbaghia)
- Spiderflower (Cleome – grow as annual, replanting seed every year)
- Tagetes marigolds (grow as annual, replanting seed every year)
Some of these plants have a wide number of species, so here are some specific recommendations from the Hole Park Gardens.
Agastache ‘Blackadder’
Agastache flowers from mid-summer to autumn. I found that reports of its hardiness varied, and I myself lost three agastache to a wet winter.
But they are stunningly long flowerers. They work in formal borders and in cottage gardens as you can see in Kathy’s Rustic Cottage garden here.
Agastache ‘Blackadder’ is pollinator friendly and flowers from mid-summer to autumn.
Chrysanthemums
The Chrysanthemums at Hole Park weren’t yet in flower when I visited, but these are such brilliant plants for the late season garden, I had to include them. People think they’re difficult to grow, because they associate them with big showy flowers for competitions. But hardy chrysanthemums are no more trouble than dahlias and far less attractive to slugs.
They flower for around three months from early autumn to the first frosts. Chrysanthemums are often the last flowers standing in my garden.
Chrysanthemum ‘Burnt Orange’ has flowered for 2-3 months from autumn to the first frosts in my garden. To find out more about growing chrysanthemums, see this post.
Diascia (Twinspur)
Diascias are not as frost-hardy as most of the other plants in this list, but Quentin thinks they are often overlooked. There are several different diascias in the Centenary Garden, including a pretty pink Diascia personata. They’ve flowered from spring to autumn.
Diascia ‘Classic White’ are long flowering plants that are perfect for edging. Unless you have very mild winters, you’d need to buy or sow new every year, but they flower for such a long time they’re worth it. Note that the herbaceous borders in the Centenary Garden have been slightly raised. This means the flowers are more visible and also that it drains better. They are less likely to lose plants in a wet winter.
Gaura (now Oenethera) ‘Rosy Hardy’
There are several different gauras (now re-named Oenethera) in the borders at Hole Park. They are all exceptionally long flowering, typically blooming for around four months from mid-summer. This pretty pink one is ‘Rosy Hardy’ and it’s about 2ft/90cm tall.
The better known Gaura lindheimerei is twice that height with white flowers tipped with pink. It can flower for up to six months from mid-summer.
Oenethera) ‘Rosy Hardy’ is a pretty, pink gaura which is flowering for months at Hole Park.
Helenium, penstemons and Kniphofia ‘Thompsonii’
This stunning autumn grouping is a trio of long flowering plants. If you dead-head heleniums, you should get two months of flowers.
And penstemons are amongst the longest-flowering plants in the border.
Kniphofias (Red Hot Poker) are often a blaze of colour in early to mid summer, but aren’t always long-lasting. However, Quentin says that ‘Thompsonii’ continues to throw out spikes of flowers throughout summer and autumn.
Helenium ‘September fox’, Penstemon ‘Garnet’ and Kniphofia ‘Thompsonii’
Japanese aster (Kalimeris incisa)
Paul Seaborne of Pelham Plants (see his advice on garden micro-climates) thinks that kalimeris or Japanese aster is very over-looked plant. It has tiny blue flowers throughout summer and into autumn. And it doesn’t even need dead-heading to keep the flowers going, says Paul.
Japanese aster (Kalimeris incisa) flowers for four months from mid-summer.
Salvia ‘Nachtlinder’
Salvia ‘Nachtlinder’ flowers from mid-summer to the first frosts. Salvias are all very long flowering plants, but the ‘Greggii’ and ‘Microphylla’ salvias can flower for six months at a time. Find out more about salvias here from the UK’s top salvia expert, William Dyson.
Stonecrop/Hylotelephium (formerly sedum) ‘Red Cauli’
There are several varieties of stonecrop/sedum at Hole Park Gardens, including ‘Matrona’, ‘Autumn Joy’ and ‘Red Cauli’. Quentin Stark says they are particularly good for the front of a border.
Hylotelephium ‘Red Cauli’ is the deepest red of the stonecrops and flowers for months on end.
Society Garlic (Tulbaghia)
Society Garlic (Tulbaghia) flowers continuously for months at a time.
See Hole Park Gardens’ beautiful herbaceous borders in video
See round Hole Park Gardens’ beautiful borders in this video. And there are extra planting tips from Quentin, too.
Pin to remember long flowering plants for late season beauty
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