Colletia paradoxa makes a perfect barrier.Photograph: Bob Gibbons/Alamy Stock Photo
Plant this If you need a barrier but find berberis too reminiscent of car parks, try anchor plant (Colletia paradoxa; ).
Dwarf sweet box packs a punch when it comes to scent.Photograph: Alamy
Plant this The spidery white flowers of dwarf sweet box (Sarcococca hookeriana var humilis) might be tiny but pack a punch when it comes to scent.
Plant this A tree that smells like candyfloss?This is the secret superpower of the katsura (Cercidiphyllum japonicum); as well as smelling divine, the leaves flame orange, red and yellow before falling.
How do watermelons grow?Unlike most crops, watermelons grow on vines that grow out of the initial sprout and can grow to be six metres long.
Plant this Garlic chives (Allium tuberosum) are the plant that keeps on giving.Harvest the mildly garlicky leaves, then enjoy the white flowers in late summer through to autumn (they are also edible).
Euphorbia characias ‘Tasmanian Tiger’ thrives in full sun.Photograph: Gap Photos
Plant this I love Euphorbia characias, and it loves me – or at least my garden.
Try liatris spicata for late summer borders.Photograph: gianpinox/Getty Images/iStockphoto
Plant this Liatris spicata or prairie gayfeather is a grand addition to a late summer border or container scheme, with flower spikes of purple or white that look exotic but are tough and hardy.
Bee balm makes great cut flowers.Photograph: Alamy
Plant this If you have moist soil, bee balm (Monarda didyma) is great.
Senecio ‘Angel Wings’: a great houseplant.Photograph: Alamy
Plant this The large, silvery leaves of Senecio ‘Angel Wings’ make a bold statement in a container in full sun.
Sneezewort does well in sun or partial shade.Photograph: Alamy
Plant this If you need a “good doer” for a white border, wildlife garden or cut-flower patch, take a look at easygoing perennial Achillea ptarmica ‘The Pearl’ – AKA sneezewort.
Singing the blues: a poison-dart frog on a mound of moss.Two years ago, I wandered into an exotic pet exhibition while on holiday in the Netherlands.
Erigeron glaucus ‘Sea Breeze’: perfect for gravel gardens.Photograph: Alamy
Plant this Get the seaside look with the drought-tolerant daisy flowers of the beach aster, Erigeron glaucus ‘Sea Breeze’.
Verbascum ‘Clementine’: spires of flowers above felted leaves.Photograph: Alamy
Plant this Verbascums are underrated.
Hydrangea ‘Kardinal Violet’ is compact enough for most gardens.Photograph: Alamy
Plant this Looking for a flowering shrub with zing?
Melianthus Major, the peanut butter plant.Photograph: Getty Images
Plant this One of the weirder common names for Melianthus major is the peanut butter plant, so if you get one, give it a sniff.
Plant this Fuchsia ‘Hawkshead’, may look delicate, but happily this is one of the more hardy of the fuchsia clan.It’s compact (1m tall) and will cope with most soils, given full sun or dappled shade.
Bees love Agastache ‘Red Fortune’.Photograph: Gap Photos
Plant this If you’re looking to delight bees, Mexican giant hyssop (Agastache mexicana) is a sound choice for sunny, well-drained borders and containers.
Deschampsia cespitosa ‘Goldtau’ is a blond, airy perennial.Photograph: Christina Bollen/Alamy
Plant this Deschampsia cespitosa ‘Goldtau’, or tufted hairgrass, is a blond, airy perennial that stays helpfully compact, at about 80cm tall, and is evergreen to boot.