June sees the beginnings of summer. Here are Wildside plantsman Keith Wiley and Lowther Castle head gardener Andrea Brunsendorf‘s choices of the best flowers to plant this month. Don't miss our round up of the best gardens to visit this month and what to plant in June. Don't miss our round up of June's gardening jobs.
June flowers: the best blooms for June
Rodgersia pinnata ‘Buckland Beauty’
A dark-pink seedling we raised from Rodgersia pinnata ‘Superba’ while at the Garden House. In the wild, rodgersias often grow on stream banks and like a moisture-retentive soil, without being waterlogged. After flowering the flowerheads in this cultivar turn dark red, and are excellent for use in dried flower arrangements. The handsome crinkled foliage appears late in the spring, with the flowering stems pushing up first, so they are vulnerable at this time to late spring frosts. This late leafing means it is possible to grow early spring bulbs among the roots.
AGM. Height 1m. Origin Garden origin, species from China. Conditions Moist but well-drained soil in full sun/part shade. Hardiness RHS H4, USDA 3a-8b. Season of interest All summer.
Find Rodgersia Pinnata 'Buckland Beauty' through the RHS
Oenothera stricta ‘Sulphurea’
This is the pale-yellow version of the Chilean evening primrose, and is a short-lived perennial or biennial that I hope never to be without. It will self-seed so, as long as there is bare ground for the seedlings to colonise, there should really be no reason to lose it.
As its name suggests, the scented flowers open a pale yellow in late afternoon, each one turning by the morning to a wonderful apricot colour for its final few hours before dropping. The whole effect is accentuated by the fact that it has a purple-red flush to the buds and stems.
Height 60-90cm. Origin Garden origin (species from Chile). Conditions Any well-drained soil; full sun. Hardiness RHS H5, USDA 6a-10b. Season of interest All summer.
Buy Oenothera stricta 'Sulphurea' from Dorset Perennials
Campanula latifolia ‘Buckland’
Another plant we raised while we were at the Garden House. A seedling from the pure-white Campanula latifolia var. alba, the purple eye and faintest flush of that colour in the white, elevates this into a classy looking perennial. Although upright in growth, I have never needed to stake this plant, and because the clump occupies very little ground space, it can provide very useful vertical accent points among lower-growing perennials.
After flowering the skeletal seedheads are also attractive for a short period before they are best cut back.
Height 1m. Origin Garden origin (species from Europe and western Asia). Conditions Any soil; full sun to part shade. Hardiness RHS H5, USDA 4a-9b. Season of interest Summer.
Buy Campanula latifolia 'Buckland' from Chiltern Seeds
Iris ensata ‘Rose Queen’
Still known by some as Iris kaempferi, the Japanese water iris is one that is happy when in growth under shallow water, but prefers to be drier when dormant. It is much loved in its native Japan, where pond levels are often manipulated through the seasons to specifically suit it.
However, it doesn’t need to be grown in water as long as the soil is moisture retentive, and it is growing close to water, where it is certainly looks at its best. ‘Rose Queen’, with its distinctive flower colour, has smaller, more delicate flowers than many other ensatas.
AGM. Height 75-90cm. Origin Garden origin (species from Japan and the Far East). Conditions Rich, moist soil; full sun. Hardiness RHS H6, USDA 5a-8b. Season of interest Early summer.
Arisaema candidissimum
The distinctive stripy pink spathes of this exotic-looking aroid make it one of the best arisaemas for flowering. It emerges from the ground as late as early June, and quickly produces flowers before the leaves appear. When it is settled these trifoliate leaves can be as much as 45cm across, at which time, it becomes a very handsome foliage plant for late summer.
The first frost of autumn will finish this display, and it will spend the next seven or eight months below ground as rounded and flattened, fleshy tubers, so make sure you mark its position well and protect it with a thick mulch.
AGM. Height 30cm. Origin China. Conditions Warm spot in part shade. Hardiness RHS H4, USDA 5a-7b. Season of interest All summer.
Find Arisaema candidissimum through the RHS
Rosa ‘Dortmund’
A climbing rose that offers glossy green foliage and clusters of white-centred, red flowers throughout summer and into autumn, which are then followed by attractive orange hips.
For 40 years this rose has unfailingly delivered clean foliage – without any resort to chemicals – and has produced masses of flowers for us in a part of the country that has a very high rainfall, in which most roses refuse to grow in for more than a year or two without regular spraying. It has thorns, so the annual tidy up and tying in tends to be a painful process, but it is so worth it.
AGM. Height 3m. Origin Garden origin. Conditions Moist but well-drained soil; full sun. Hardiness RHS H5, USDA 4a-10b. Season of interest All summer.
Buy Rosa 'Dortmund' from Trevor White Roses
Kniphofia thomsonii
This Kniphofia is very different to most people’s vision of a red hot poker. Instead of having a closely packed spike of flowers, this species looks more like an aloe, with widely spaced, soft-orange flowers, each gracefully curving downwards. Its growth habit is also different as, like the flowers, instead of making a sizeable clump, it runs gently forming a widely spaced colony of rosettes, each with a limited number of decumbent leaves.
Repeat flowering through the summer. If there is one catch, it would have to be that it is not quite as hardy as some.
Height 60-90cm. Origin East Africa. Conditions Well-drained soil; full sun to light shade. Hardiness RHS H3, USDA 7a-10b. Season of interest Summer.
Convolvulus althaeoides
A bindweed that I actually love. It was more than 25 years ago when I first managed to get a tiny root to survive and grow. In Crete, where we first caught sight of it, it carpeted tilled ground among some olive groves, and covered sizeable, steep, sunny roadside verges. It was not until I managed to replicate those conditions did it deign to settle in and spread.
Now it runs underground, spreading its beautiful silver foliage and clean pink flowers through a soft purple-blue catmint, a wonderful combination lasting for many weeks.
Height Scrambling to 60cm. Origin Mediterranean. Conditions Well-drained soil; full sun. Hardiness RHS H3-4, USDA 6a-8b. Season of interest All summer.
Find Convolvulus althaeoides through the RHS
Eryngium x zabelii
Eryngiums are more commonly known as sea hollies because of their prickly leaves and because the natural habitat of some species is in coastal areas. In a garden setting though, all they ask for is a sunny, well-drained spot, where for many weeks in summer, they will produce their startling, cone-shaped flowerheads surrounded by a ruff of vicious-looking bracts.
There are several cultivars available of this hybrid varying slightly in the intensity of the blue, both in the flowerheads and the flower stems, but all are good. Easily propagated by root cuttings in late winter.
Height 60-90cm. Origin Garden origin. Conditions Well-drained soil; full sun. Hardiness RHS H5, USDA 6a-9b. Season of interest Summer.
Dierama pulcherrimum
Wand flowers, or more romantically angel’s fishing rods, are one of my favourite perennials. With their wiry, evergreen, grassy leaves, many visitors ask us what the flowering grasses are. Dieramas are actually bulbs from South Africa, most of the species growing at altitude, which makes them hardy in most of the UK.
This species flowers later than most, usually through July, with pink, purple, white, or in this case pale amethyst, bells hanging beneath wiry flower stems. The silvery seedheads that follow are also attractive, moving in the slightest breeze.
Height 1-2m. Origin South Africa. Conditions Well-drained soil; full sun. Hardiness RHS H3-4, USDA 8a-10b. Season of interest Late summer for flowers.
Luzula sylvatica ‘Marginata’
One of the most versatile woodrushes. Performs best in slightly acidic, moisture-retentive soils in dappled light, but adopts to difficult growing conditions ranging from dry shade to poorly draining soils in full sun. Its dense tufts gradually spread on short runners to create an impenetrable continuous groundcover. The narrow leaves are evergreen with neat creamy-white margins, and its golden-brown flower panicles dance loosely above the foliage until midsummer. AGM. Chosen by Andrea Brunsendorf
Height and spread 45cm x 45cm.
Origin Europe, including Britain, through to the Western Caucasus.
Conditions Dry to moist, organically rich soil; full sun to shade.
Hardiness RHS H7, USDA 4a-9b.
Season of interest Flowers late April to July; foliage year round.
Brunnera macrophylla ‘Langtrees’
Lovely long sprays of forget-me-not flowers emerge in spring and last until midsummer. The foliage, marked with metallic spots, forms attractive mounds that can persist throughout the season. If it catches too much sun, heat or drought, you can encourage new foliage with a summer chop provided it’s kept moist, and a second bloom will follow in August. An essential groundcover here at Lowther, suppressing weeds with its large leaves that are unpalatable to rabbits. What’s not to like? AB
Height and spread 50cm x 50cm.
Origin Garden (species Western Asian, in the Caucasus and northeastern Turkey).
Conditions Moist, well-drained, organically rich soils; part to full shade.
Hardiness RHS H6, USDA 3a-7b.
Season of interest April to June.
Aquilegia vulgaris
I remember picking this species in the wild as a child, when I would always favour the bluish-mauve, nodding, bonnet-like flowers over the dusky pink ones. However, it’s a short-lived perennial that also has a long history in cultivation. I love to plant it with mid-season tulips, so the colour-saturated tulips can emerge through its fresh and delicate spring foliage. Easy to grow from seed and once established in optimum conditions, it will self-seed almost too freely, as it does in Lowther’s Rock Garden, which is currently being reimagined with a Dan Pearson planting design. AB
Height and spread 70cm x 30cm.
Origin Europe, including Britain.
Conditions Moist, well-drained, moderately rich soil; full sun to part shade.
Hardiness RHS H7, USDA 3a-8b.
Season of interest Late April to early July.
Onoclea sensibilis
This deciduous fern emerges in late spring, with apple-green fronds that mellow to pale green. Its rhizomatous rootstock continues to produce new arching leathery fronds throughout the season. Woodier and fertile fronds, covered in bead-like spores, appear in late summer, providing attractive winter interest when foliage gets cut down by the first autumn frost. Known for its sensitivity to frosts and drought, hence its common name of sensitive fern, it can cope with poorly drained sites and, in favourable conditions, can become a thug if not checked. AGM. AB
Height and spread 60cm x 1.5m.
Origin Eastern North America.
Conditions Moisture-retentive, organically rich soils; part to full shade.
Hardiness RHS H6, USDA 4a-8b.
Season of interest Late April to first frost.
Papaver cambricum
The Welsh poppy is native to the British Isles moist rocky banks, stream sides and waste grounds. It is an undemanding, tap-rooted perennial that some might think of as unruly in the garden because, when happy, it self-seeds prolifically. I love it, especially the first flush of delicate cup-shaped yellow flowers in late spring and the fact that it can hold its own company until early autumn. A real charmer that looks great among ferns and along wild woodland paths, where it glows in the dappled light. AB
Height and spread 50cm x 30cm.
Origin Coast of western Europe and Britain.
Conditions Moist, well-drained, moderately rich soils; full sun to shade. It is best in dappled shade.
Hardiness RHS H7, USDA 6a-8b.
Season of interest June to September.
Thalictrum aquilegiifolium ‘Album’
This charming perennial seems to appear overnight in spring with its delicate, divided green basal foliage. These aquilegia-like leaflets carry on up the slender purplish stems, which are topped with fluffy clouds of pure-white flowers from early summer onwards, bridging the June gap. This species is one of the early flowering meadow rues. It will mostly grow true from seed if you have only the white-flowering form. Easy to grow, and trouble-free, it’s a superb plant that even rabbits and deer will leave alone. AB
Height and spread 1m x 60cm.
Origin Europe to Asia.
Conditions Moist, well-drained, organically rich soil; full sun to part shade, prefers dappled light.
Hardiness RHS H5, USDA 5a-8b.
Season of interest June to July.
Read our guide to growing thalictrum
Lamium orvala
With its large, heart-shaped, green leaves, this handsome foliage plant resembles a wild nettle without the sting. The balm-leaved deadnettle is an extremely ornamental and long-lived perennial with whorls of pink-lipped, velvety flowers and a neatly poised habit. It creates a real presence in a partially shaded border from late spring through late summer. It contrasts well with fine-textured shade plants such as ferns, forest grasses and various spring bulbs. I first saw it beautifully sited in Piet Oudolf’s garden, Hummelo, and knew I would grow this non-invasive woodlander one day. AB
Height and spread 50cm x 50cm.
Origin Central Eastern Europe.
Conditions Moist, well-drained, organically rich soils; best in partial to full shade.
Hardiness RHS H7, USDA 4a-8b.
Season of interest Late April to July.
Magnolia wilsonii
A deciduous woody plant and a real botanical treat that flowers in early summer, avoiding those sneaky late frosts. Its pendent, saucer-shaped, white flowers and crimson stamens remind me of lofty meringues with a raspberry in the centre. Discovered in China by the eminent plant hunter Ernest Wilson, it has mesmerised gardeners for more than a century with its almost ethereal and divine floral effect. Best in a sheltered position so that once it has reached its full height you can walk under this small tree and look up into those beautiful flowers. AGM. AB
Height and spread 8m x 8m.
Origin South-central China.
Conditions Moist, well-drained, organically rich soils, preferably slightly acidic; full sun to part shade.
Hardiness RHS H6, USDA 6a-9b.
Season of interest Mid-May through June.
Clematis montana var. grandiflora
A strong-growing deciduous climber, reaching up to 12m, even on a north-facing wall. It produces an incredible abundance of glittering white star-shaped flowers that are slightly fragrant. This group of clematis does not require routine pruning; but, if you want to restrict its spread, cut overlong shoots back to healthy buds. Remember, like every other clematis, it likes cool roots, ideally shaded by other plants. Its rambling habit adds to the romance of Lowther’s ruins, enhancing the dreamy atmosphere of rebirth. AGM*. AB
Height and spread 12m x 4m.
Origin Throughout mountainous areas of Asia, from Afghanistan to Taiwan.
Conditions Moist, well-drained, organically rich soils; full sun to part shade.
Hardiness RHS H5, USDA 4a-9b†.
Season of interest May to June.
Tilia x europaea
This vigorous lime makes up many grand avenues, including one here at Lowther dating back to the 17th century. These formerly pollarded trees possess so much character with their dense thickets of basal suckers and burrs. In winter, the slender twigs and leaf buds turn red, the latter resembling small boxing gloves. Taking in the sweet fragrance of the cream-coloured flower clusters, accompanied by the buzz of bees frantically feeding on them, is a special summer moment and reminds me to pick some for my evening infusion. AB
Height and spread 35m x 15m.
Origin Europe, including Britain (hybrid between T. cordata and T. platyphyllos).
Conditions Moist, well-drained, moderately rich soil; full sun to part shade.
Hardiness RHS H6, USDA 3a-7b.
Season of interest Flowers June to July; winter stems until first leaf bursts.