12 "hidden gem" garden flowers you’re not growing yet – including chocolate-scented cosmos

"Airy, almost frothy pink flowers that soften the front of borders and contrast with more structured perennials, " says Mathew.

"It also has cultivated forms, such as Lychnis flos-cuculi ‘Jenny’, which has fuller, double flowers and a more polished-garden feel, while retaining that same lightness."

Alliums are one of the few ‘add to the list and forget about them’ plants, says Matthew.

"They require nothing more than being planted and take care of their pollinators. They also create movement as their beautiful, globe flower heads become seed pods that remain all summer and are a great way to add artistic structure to a garden."

Pretty cardinal flowers can be a valuable tool in the garden for adding personality.

"Though cardinal flowers are often overlooked, they are one of my favourites to bring colour, height and interest. The flower spikes are bright scarlet, making them a statement in any flower bed, border, or woodland garden," says Lotte.

Charlotte explains that the unassuming Red Campion is "ideal for shadier edges, pairing beautifully with ferns, hostas and perennials."

She goes on: "There are also cultivated forms like Silene dioica ‘Clifford Moor’, which introduce softer, variegated foliage, allowing it to sit more deliberately within planting schemes."

"Common Knapweed is long-flowering, pollinator-rich and surprisingly bold in colour, making it a useful addition among later summer perennials," Charlotte suggests.

"It sits comfortably alongside cultivated cornflowers such as Centaurea Montana and its various blue and purple selections, which bring a larger, more ornamental flower but a similar character."

Passion flower varieties are already popular, but gardeners are seeing a move away from the traditional English garden towards tropical themes. Gardener Lee Furness says: "Passiflora, clematis and echinacea to give your garden an exotic feel."

Field Scabious is a "brilliant bridging plant that threads through planting schemes and works well with grasses and roses," Charlotte says. "Its cultivated relative, Knautia macedonica, is already widely used in garden design, offering crimson tones and a longer flowering season while keeping that same airy, informal habit."

"Bougainvillaea gives a simple effect and is fairly low maintenance," says Lee. Bougainvillaea must be grown in pots to be moved indoors or into a greenhouse during winter, but it makes for a very special summer plant.

"The common spotted orchid, Dactylorhiza fuchsii, and hardy orchids like slipper orchids, Cypripedium, are also great options," Lee adds.

"You can find the Ivy-leaved Toadflax, also known as Kenilworth Ivy, in the wild all around the UK," says Lotte. "It’s a hardy, low-maintenance perennial that grows fast. It features small ivy-shaped leaves and delicate blooms in mauve and yellow. This pretty plant can be grown as a groundcover, but loves to climb and makes the perfect addition to a rock garden."

Matthew predicts this hidden gem will be very popular in 2026.

"These versatile bulbs sprout a beautiful mix of purple and white flower petals that appear to grow from the centre of the flower - hence the name 'nodding bell'," says the gardening expert. "Its elegant meadow aesthetic is perfect for a naturalistic gardener and can be used in more discreet areas that require something alternative."