Marian Boswall: 21 sustainable and beautiful plants

Part two of our series: Our changing climate is already changing the way we garden. But what plants should we grow in this changed world? Must we sacrifice lushness for toughness? We asked five leading designers whose gardens have sustainability at their core for their ideas. 

Photo: Katie Spicer
Photo: Katie Spicer

Marian Boswall

Marian’s selection includes plants that will protect soil, lock up carbon, and provide food and shelter for wildlife but, most of all, are simply very beautiful.



Agastache ‘Black Adder’
©Jason Ingram

A member of the hyssop family, this perennial has long been used in herbal medicine as an antiseptic. This dark, giant cultivar is the most hardy and has edible flowers that go on for months and are always covered in bees. Resistant to drought and also happy in clay it makes a great vertical accent. H 70cm. S 50cm. C Well-drained, moderately fertile soil; full sun. SI June to November. HR RHS H4, USDA 6a-9b.



Allium schubertii
©Jason Ingram

These enormous, lilac-coloured allium flowers look fabulously quirky in any border but are also great bee plants. The seedheads dry extremely well, creating super sustainable Christmas decorations. A perennial bulb. H 1m. S 1m. C Moist, well-drained soil; full sun or partial shade. SI April to May. HR RHS H4, USDA 5a-8b.



Arbutus unedo.
© Claire Gainey / Alamy Stock Photo

Flowering in winter this small, evergreen tree or large shrub is a useful forage plant for brave bees out on a cold sunny day. Its edible strawberry- like fruits make it a great permaculture tree to add the mid layer of a forest garden. H 5m. S 5m. C Moist, well-drained soil; full sun. SI September to January. HR RHS H5, USDA 7a-10b.



A bridesmaid for the front of every sunny border. A perennial from the Mediterranean, it does well on chalk and sand, and is also happy on clay. Loved by bees and caterpillars, it is deliciously aromatic so less loved by rabbits. H 30cm. S 45cm. C Well-drained, moderately fertile soil; full sun to partial shade. SI May to November. HR RHS H5, USDA 5a-7b.



A brilliant perennial bulb to naturalise in a meadow setting. The dark-blue spires above narrow leaves are loved by bees and need very little attention, spreading gradually by seed if they are happy. H 60m. S 50cm-1m. C Moist but well-drained soil; full sun or partial shade. SI April to May. HR RHS H4, USDA 5a-9b.



The Botanic Nursery and Foxglove Collection (28th May 2009)
©Jason Ingram

A tall and elegant beauty to brighten up a shady spot. Nodding trumpets provide a perfect landing spot for a bee. A short-lived perennial that looks great coming up through ferns and is less promiscuous than the common foxglove D. purpurea. AGM. H 90cm. S 30cm. C Well-drained, moderately fertile soil; full sun to part shade. SI May to July. HR RHS H6.



A key base-layer player that is ideal to cover and protect the soil to prevent erosion from heavy rain, and lock in carbon. This epimedium holds  ts elegant pink flowers above the foliage, just cut them back in early spring before flowering. A super easy plant for shade. H 25cm. S 30cm.C Humus-rich, moist well-drained soil; part shade. SI Year round. HR RHS H5, USDA 5a-8b.



Iris 'Benton Nigel'
© Howard Rice / Gap Photos, Sarah Cook, National Collection of Sir Cedric Moris Irises

A pop of deep-blue colour that appears just when we need it, this elegant Cedric Morris iris is from the justly famous Benton stable of irises. These are less showy than modern bearded irises, and once you’re smitten with their subtle colours, I guarantee you’ll find yourself wanting to collect all the colours. H 1m. S 40cm. C Light, well- drained soil; full sun. SI April to June. HR RHS H4.



A blue to stop you in your tracks, this lovely little perennial flax speaks of summer skies and linen frocks. Great for a gravel garden or dry front of border, it’s hardy but looks so delicate with large heads on slender stems. H 50cm. S 40cm. C Light, well-drained soil; full sun. SI June to August. HR RHS H4, USDA 5a-8b.



The winter scent of a warm mahonia is such a waft of ‘welcome home’. This softer version of the shrub lacks the strident architecture of the usual mahonias and is easy to fit into any scheme. Good winter bee forage. AGM. H 60cm. S 12m. C Moist but well-drained soil; full sun to part shade. SI April to June. HR RHS H4, USDA 7a-10b.



The humble crab apple finds a home in nearly every garden I design. In late winter the birds mob the pretty fruits when all else is gone. In spring, a daily visit to inhale the scent and listen to the bees is food for the soul. AGM. H 4-8m. S 4-8m. C Moist, well-drained soil; full sun or part shade. SI April to May. HR RHS H6, USDA 4a-8b.




This hardy annual is so simple and yet so complex, with a centre like a passion flower and stunning seedheads too – a firm favourite for dry gardens especially. Great for bees, this is an annual that easily self-seeds, and the seeds are edible too. H 45cm. S 25cm. C Light, well- drained soil; full sun. SI June to November. HR RHS H3, USDA 2a-11.



Keith Wiley Plants (23rd July 2019)
©Jason Ingram & John Martin / Alamy Stock Photo

Very sweet nectar makes this a bee and butterfly magnet, and the unusual pink flowers drip down among bracts like hops, making it a very Kentish plant. Great for pots and window boxes where the scent can drift in when brushed. AGM. H 30cm. S 20cm. C Light, well- drained soil; full sun. SI July to September. HR RHS H4, USDA 6a-9b.



Derry Watkins/Special Plants Nurseryman's Choice - June (6th Jun
©Jason Ingram

If you have only one annual, this has to be it. The most delicate of umbels that threads up through the border or in the gravel garden, pure white and brimming with forage for pollinators right to the first frosts. A hardy annual it self- seeds in light soil. AGM. H 60cm. S 60cm. C Light, well-drained soil; full sun. SI June to October. HR RHS H7.



Phacelia Tanacetifolia. Fiddleneck
© Tim Gainey / Alamy Stock Photo

A plant that helps feed both the soil and the bees. Phacelia is a pretty, green manure that you cut down while in flower to allow the nutrients to stay below. It will hum with beneficial insects all summer, a fast groundcover and prolific self-seeder. H 1.2m. S 45cm. C Any fertile soil; full sun. SI June to September. HR RHS H4.



An easily overlooked, but key wildflower meadow plant. Self heal is also an essential healing herb and soil-knitting stalwart in the sward. Drink it in an infusion, or leave for the bees. H 20cm. S 20cm. C Moist but well-drained soil; full sun or partial shade. SI April to August. HR RHS H5.



Rosa spinosissima ‘Dunwich rose’
© Tim Gainey / Alamy Stock Photo

A shrub rose that looks just as at home in a wild garden as it does in a more polite setting. Single, creamy flowers are stunningly simple and a perfect landing spot for pollinators. In the autumn dark-blue hips provide a real talking point and food for birds too. H 60cm. S 1.2m. C Moist, well-drained soil; full sun or partial shade. SI April to June. HR RHS H6, USDA 3a-9b.



A tough prairie perennial that does well in most places including heavy soils in sun. The unusual cone heads are food for butterflies and bees and the seedheads stand through the winter attracting goldfinches and look striking against a low, winter sun. H 1.2m. S 60cm. C Any fertile soil; sun or part shade. SI August to October. HRRHSH7.



Small tree or shrub. A beautiful addition to any sustainable garden. The pretty, spring flowers and deep purple autumn fruits are both delicious and used medicinally. Plus great forage for wildlife. H 4m. S 3m. C Moist, well-drained soil; full sun. SI Spring and autumn. HR RHS H6, USDA 5a-8b.



With masses of starry parsley heads above pretty, fern-like, cut leaves, this is a delightful froth of bee fodder for any border. Its red stems look wonderful with Sanguisorba ‘Tanna’ bobbing through. A medicinal plant in the permaculture garden. AGM. H 1m. S 1m. C Moist, well-drained soil; full sun. SI July to September. HR RHS H6, USDA 6b-10b.



With a perfume to turn heads in early summer, this is my favourite of this useful genus. Flowers are white to pink in pom-poms with red edges, and are loved by bees. The glossy green leaves turn red edged in autumn. A fabulous mid layer shrub. H 1.8m. S 2m. C Moist, well-drained soil; full sun to full shade. SI April to July. HR RHS H6 USDA 4a-7b.