A foolproof planting recipe for the perfect summer container

Tired of the same old ideas as regards the perfect summer container? Trying to think of a more perennial, sustainable solution to the challenge of providing a long-lasting, exuberant display? Me too, which is why I asked June Blake, one of the country’s most respected and creative gardeners, to come up with the perfect planting ‘recipe’. The result, as befits a woman known for her thoughtful, painterly way with plants, is a dreamy mix of flowers and foliage guaranteed to fill your heart with joy from now until the first frosts of autumn.

Ingredients

– A large, deep container/pot

– Plenty of crumbly, homemade compost, or failing that, a high-quality alternative that’s not peat-based (see enrich.ie)

– Handfuls of horticultural grit to mix in with the above

– Some broken up pieces of polystyrene board, to fill the base of your container without adding too much weight.

– Salvia microphylla “Cerro Potosí” (height 80cm): A tough, long-flowering firecracker of a shrubby salvia, with electric-pink flowers from June until late autumn. Loves full sun and sharp drainage. May need winter protection in very cold gardens.

– Astrantia “Bo-Ann”: A fantastically floriferous, slug-proof, hardy perennial (height 70cm) with silver-pink, starry flower bracts from late spring until early autumn. Likes full sun/light shade, and a rich, moist soil.

– Geranium “Ann Thomson’” A compact, hardy perennial geranium (height 40cm), which produces a multitude of black-eyed, dark-purple flowers from June until October, and enjoys full sun/ light shade, and a fertile, well-drained soil.

– Aeonium “Schwarzkopf”: A slow-growing, tender, evergreen succulent, with fleshy, chocolate-purple leaf rosettes on the end of long branches.

– Cosmos atrosanguineus (Chocolate cosmos): A tender, tuberous, sun-loving perennial (height 45cm) with chocolate-scented, crimson-maroon, daisy-shaped flowers from July until the first frosts, when it should be lifted and overwintered under cover

– Epimedium pubigerum: Dainty, hardy perennial with heart-shaped, bronze tinted leaves and sprays of delicate creamy-pink flowers throughout the summer.

– Sedum telephium “Purple Emperor”: A fleshy, sun-loving, hardy perennial (height 45cm) with fleshy, purple-flushed leaves and crimson/purple flowers from August to October.

– Persicaria “Red Dragon”: A handsome, hardy perennial foliage plant with spear-shaped purple leaves overlaid in silver (height 75cm)

Instructions

Fill the base of a large container/pot/tub with broken pieces of polystyrene, leaving roughly 38-40cm to the top. Add homemade compost (30cm deep), mixed with generous handfuls of coarse horticultural grit to improve drainage. June’s compost is made to perfection, but if yours isn’t, then add some good quality garden soil to improve the texture, or source some compost from enrich.ie. The finished level of the compost (firm it down gently before planting) should be about 8-10-cm below the lip of the container.

Now assemble your plants, treating them almost as a floral arrangement and planting them much closer together than you would in a border. Start with that great big show-off of a salvia, Salvia ‘Cirro Potosí’, giving it pride of place near the centre of the pot. It likes especially sharp drainage and a relatively poor soil so June employed the clever tactic of sinking it, still in its own plastic pot and in its own free-draining compost mix, into the urn. June’s plant is a mature specimen overwintered in her polytunnel, giving it an almost sculptural, bonsai-like effect, but younger plants will take a little while to reach that size.

Next comes Geranium ‘Ann Thomson’, a brilliant workhorse of a plant. June used three for her very large, vintage cast-iron urn, but for smaller pots, scale the planting down by using one, placing it near the edge of the container where its flowers will spill over the sides.

The same goes for the long-flowering Sedum ‘Purple Emperor’ whose fleshy purple flower clusters are beloved by bees, and the dainty little Epimedium pubigerum, whose delicate leaves and pale pink flowers will add a subtle textural element.

The handsome foliage plant, Persicaria’ Red Dragon’ needs to go towards the centre of the container, as should the chocolate cosmos and Astrantia ‘Bo Ann’, a lovely, hardworking perennial plant which flowers its heart out all summer long. Now finish off with the wonderfully whacky Aeonium ‘Shwarzkopf’, whose fleshy, purple leaf-rosettes will add weight and a hint of eccentricity. Again, June used four plants for her large container, but one is sufficient for a smaller pot.

Once the planting is complete, give your container a really generous watering, using a fine spray to avoid damaging soft foliage and stems.

To preserve moisture and prevent wet compost spattering onto the plants, cover any bare compost with a 5cm-deep mulch of horticultural grit, gently tucking it around the plants. Water lightly again to wash off any debris. After that, it’s a simple case of regular watering and deadheading, as well the occasional bit of careful grooming/ clipping to ensure the best balance of foliage/ flowers. Easy-peasy.

Most of the plants listed above can be sourced from June Blake’s Wicklow garden/nursery, near Blessington, Co Wicklow, open Wednesday- Sunday from 11am-5.30pm (see juneblake.ie), as well as some other Irish specialist nurseries, including mountvenusnursery.com, camolinpottingshed.com and kilmurrynursery.com

This week in the garden

– Keep late-summer flowering perennials such as Helenium, Phlox paniculata and the more upright varieties of Sedum compact and floriferous by giving them the ‘Chelsea Chop’, which involves cutting the plants back down by between a third and a half. See rhs.org.uk for detailed instructions.

– It’s now safe to plant out dahlias, gladioli and tender bedding plants/ annuals as long as they’re properly hardened off. Water the plants well after planting and make sure to protect them against slug damage, which is always most likely in the days immediately after planting.

– Continue sowing vegetable seeds: carrots, beetroot, parsnips, turnips, runner beans, French beans, courgettes, chard, radish, peas, spinach, lettuce, kale, winter cabbages, scallions and florence fennel can all be sown this month, but hurry.

Dates for your diary

Tuesday 24th May- Saturday 28th May, This year's RHS Chelsea Flower Show includes main avenue show gardens by two Irish designers: Paul Martin's 'Garden of Mindful Living' and Diarmuid Gavin's 'The British Eccentric's Garden', see rhs.org.uk

Gardener and plantswoman Derry Watkins of Special Plants Nursery, near Bath in the UK ,will be giving a series of lectures in Ireland next week, with her plants for sale at all events: on May 24th (8pm) at Foxrock Pastoral Centre for Foxrock Garden Club, talk open to all, see foxrockgardenclub; on May 25th (8pm) at Deer Park Hotel, Howth, for Howth & Sutton Horticultural Society, and on Thursday May 26th (8pm) at Lavanagh House, Ballintemple, Cork, for the Cork Branch of the Alpine/Hardy Plants Society, see alpinegardenspociety.ie,;

Friday 27th- Sunday 29th May, Mallow Home & Garden Festival, including ISNA Plant Fair, see exhibitionsireland.ie