Plantsman’s favourites Hunting Brook’s Jimi Blake chooses his ten favourite plants for September
Autumn may be knocking at the door, but Jimi prolongs the interest in his late-summer borders with long-flowering perennials, a quirky canna and a ghostly, cylindrical cactus
HELIANTHUS ‘BITTER CHOCOLATE’
This is similar to the funky, willowleaved, perennial sunflower Helianthus salicifolius but with wider leaves. For years I have grown H. salicifolius for its foliage, but it rarely flowers due to our cool summers, whereas H. ‘Bitter Chocolate’ flowers throughout August and September with yellow flowers that – true to the name – emit the most divine smell of chocolate. It is more upright than H. salicifolius, which, in my experience, tends to flop. I propagate it by division or basal cuttings in spring.
Height 2m.
Origin Garden (species North and
Central America).
Conditions Moisture-retentive soil; full sun.
Hardiness RHS H4†.
Season of interest August to September.
PENNISETUM ALOPECUROIDES ‘RED HEAD’
This is a selection by Brent Horvath of Intrinsic Perennial Gardens in the USA. I first saw it grown at RHS Garden
Wisley a few years ago where it absolutely stole the show as the best ornamental grass. It has large, red, bottlebrush plumes that turn purple in autumn and then beige in winter. I grow plants in large pots in my polytunnel until they are in full flower in July or early August, as I can never rely on pennisetums to flower in the cool summers here at Hunting Brook. I then plant them into the garden, woven through the dahlias and lateflowering perennials. AGM*.
Height 80cm-1m.
Origin Garden (species Southeast Asia). Conditions Well-drained soil; full sun. Hardiness RHS H3, USDA 5a-9b.
Season of interest August to November.
AGAPANTHUS ‘BLACK MAGIC’
I imagine that many of you have grown agapanthus if your climate allows. I have to be honest, I had never grown them until last year, probably because I hadn’t used much blue in the garden up until that point. When planning my planting design for the new sand garden,
I decided it was time to give agapanthus a go. I searched for the plant with the darkest flowers on the agapanthus Facebook page and came up with Agapanthus ‘Black Magic’. This agapanthus is derived from A. inapertus, characterised by pendulous flowers.
It is deciduous and seems to be hardy here at Hunting Brook.
Height 80cm-1.2m.
Origin Garden (species South Africa). Conditions Well-drained soil; full sun. Hardiness RHS H3.
Season of interest August to September.
SALVIA PATENS ‘GUANJUATO’
This cultivar was discovered in 1991 near Guanajuato in Mexico and the name means ‘place of frogs’. The flowers are dark blue and larger than the straight species, and it is much superior to any of the other cultivars. This is the plant that inspired me to make greater use of blues and silvers in one of my sand gardens. Salvia patens is a tuberous perennial that I dig up in the autumn, pot up, and leave in an unheated greenhouse over the winter. I rarely water it in winter as this can cause rotting. I propagate it by cuttings from May to July as the cuttings need to form a small tuber before winter to succeed.
Height 90cm.
Origin Mexico.
Conditions Well-drained soil; full sun. Hardiness RHS H3.
Season of interest June to September for flowers.
SANGUISORBA ‘BLACKTHORN’
I have grown many different sanguisorbas over the years but ‘Blackthorn’ has always remained my favourite. It has tall, robust stems with deep, reddish-pink, bottlebrush flowers that, unlike those of many other sanguisorbas, tend not to fall over. I weave it through my exotic border for the repetition of vertical flower spires in late summer and autumn.
It looks at its very best when backlit by the rising or setting sun, and makes a wonderful cut flower in autumnal arrangements. I propagate it by division in spring just as it is coming into growth.
Height 1.2m.
Origin Garden.
Conditions Well-drained, moisture-retentive soil; full sun. Hardiness RHS H7.
Season of interest July to November.
PODACHAENIUM EMINENS
When I first saw this plant growing in the gardens at Mount Stewart in Northern Ireland, I was blown away by its spectacular, architectural foliage. Commonly known as the giant tree daisy, it comes from the highland cloud forests in Central America and Mexico. The oversized, scented leaves are similar to those of Paulownia tomemtosa but the new growth is silver and bronze. I use it in my tropical planting each summer and bring it into the unheated glasshouse for the winter. I am delighted to say that I managed to root some cuttings last summer.
Height 80cm-1.2m.
Origin Central America and Mexico. Conditions Fertile, well-drained soil; full sun.
Hardiness RHS H2.
Season of interest August to September.
HEDYCHIUM WARDII
I love hedychiums but Hedychium wardii and H. forrestii, both of which are hardy at Hunting Brook, are the only forms that flower for me. Hedychiums begin their growth during the monsoon season in their native habitats. H. wardii has large, bright-yellow, cone-shaped flowers from August to September with a wonderful scent. I originally planted lots of hedychiums on the slopes of a valley, but it was too dry for them to grow well, so I transplanted them to a border where they now flourish. I propagate them by division in spring, or seed sown fresh in autumn.
Height 1.5m
Origin Assam.
Conditions Rich, moisture-retentive soil; full sun.
Hardiness RHS H4.
Season of interest August to September for flowers.
CANNA ‘SÉMAPHORE’
I will never forget seeing this canna for the first time in Paloma Gardens on New Zealand’s North Island. I made a note of it on my wish list and eventually managed to buy it two years ago, but it actually dates back to 1895. It has dark-bronze leaves and the most beautiful mango-orange flowers that start flowering in midsummer. Unfortunately, most cannas don’t flower in our cool summers at Hunting Brook, so I grow most of them for their foliage only. I propagate my cannas by division in spring, making sure each division has a pointed growing snout.
Height 80cm.
Origin Garden.
Conditions Rich, moisture-retentive soil; full sun.
Hardiness RHS H3.
Season of interest August to October.
ARALIA ECHINOCAULIS
In 2002 I went on a plant-hunting expedition in central China, following in the footsteps of plant hunter Augustine Henry, who made the journey around
100 years ago. We discovered Aralia echinocaulis on this trip and brought back seed. I grew it on and the resulting plants are now taller than my house and have become a signature plant at Hunting Brook. They have a light canopy so it’s possible to grow sun-loving plants beneath them. They have spiky trunks when young, and spectacular, bipinnate foliage. It rarely suckers for me but if it does
I pot it up to swap with friends.
Height 5m.
Origin China.
Conditions Fertile, well-drained soil; full sun.
Hardiness RHS H7.
Season of interest Year round.
CLEISTOCACTUS STRAUSII
I grew cacti as a child and only returned to growing them a few years ago in order to create a summer cactus display in the gardens at Hunting Brook. Cleistocactus strausii, commonly called the silver torch cactus, grows high up in the mountains in its native habitat. It is a columnar cactus with a white, woolly appearance thanks to its short, silvery spines. I grow them in my borders combined with perennials and quirky foliage plants. They grow fast in our cool, wet summers and are brought into the house for the winter. I love the unexpected look on people’s faces when they see cactus happily growing in the Wicklow hills. AGM.
Height 1-1.5m.
Origin Argentina and Bolivia. Conditions Well-drained soil; full sun. Hardiness RHS H2.
Season of interest Year round.