How Dahlias, Magnolias and even Japanese Knotweed can perk up your dishes

Hosta shoots can be stir-fried, magnolia flowers pickled, and even dreaded Japanese knotweed (please don't grow it) can be made into crumbles, according to Matthew Oliver, horticulturist for the Global Growth Vegetable Garden at RHS Garden Hyde Hall.

Here are his tips on which common garden plants, not known for their culinary value, can add flavour to your dishes...

Daylily (Hemerocallis)

"I grow the straight species H. lilioasphodelus, of which the flowers are edible, much like a courgette flower. They are a very nice in a salad and start off with a sweet flavour, then are more peppery on the finish.

"The big, blousy large-flowered modern cultivars aren't as nice, as they've been bred for scent, and taste a bit floral and overpowering to me - watch out for pollen beetles too!

"The flower buds can be picked and sauteed, the flowers can be stuffed with just about anything, and are also used in hot soups."

Hosta

"You can eat the young shoots or 'hostons' in spring before they unfurl, much like asparagus. I'm told stir-frying is the best."

Hardy ginger

"We grow a hardy ginger, Zingiber mioga, that could be considered an ornamental, grown for leaf and flower in a tropical style garden. This one does have edible roots, but is mainly grown for the inflorescence (a flower) that appears on the soil surface in the summer.

"In Japan, China and Korea the shoots and 'buds' (young inflorescences) are a popular vegetable."

Dahlia

"The dahlias we grow are from a Swiss nursery called Lubera (lubera.co.uk) who market them as DeliDahlias(R). I'm yet to do a taste test cooked, but I don't recommend them raw!

"Flavours and textures of dahlias can vary greatly from one variety to another. According to the nursery, the flavours of the DeliDahlia varieties grown at Hyde Hall range from asparagus to celery, to the interesting sour-smoky flavour of 'Fantastic'. Other dahlias are reported to have tastes similar to spicy apple, carrot and water chestnut. Both the flowers and tubers are edible."

Rudbeckia laciniata

"This was an important Native American food plant and is now an easily available herbaceous perennial for the border. Known as sochan to the Cherokee tribe, this plant grows wild in large areas of the United States.

"It is said to have a herbal taste with flavours similar to celery. The young leaves are best for cooking and eating, though older leaves can also be cooked for a longer time - they become more fibrous and stronger in flavour as they grow."

Japanese knotweed

"I have eaten Japanese knotweed crumble before - it was much like rhubarb crumble and I would eat it again for sure."

Mix the knotweed with some cooking apples for the filling and you should get a delicious dessert.

Other yummy ornamentals

The RHS states that other edible ornamentals include:

Alpine pinks: The flowers have a sweetly spicy clove-like flavour that can be used to flavour sugar or decorate cakes and cocktails.

Fuchsia: Fuchsias make a great garnish for salads and can also be crystallised for decorating cakes and desserts, but all green or brown bits should be removed, as well as the stamen and pistils. The berries are edible too and can be made into jam.

Gladiolus: The flowers have a flavour similar to lettuce, and can be stuffed for a beautiful floral canape, but the middle of the flower should be removed before using or eating. Petals can add colour to salads.

Hibiscus flowers: Remove any pollen, and then use the flowers to make a slightly citrus-flavoured tea, or use the petals to decorate fruit salads.

Honeysuckle: The flowers have sweet-tasting nectar and can be made into a syrup. The leaves are also edible in salads, and can be used to make a tea.

Magnolia petals: The petals taste similar to how they smell - they are usually pickled rather than eaten raw, and can then be used in salads. They can also be used to infuse honey or vodka with a sweet and spicy flavour.

Peony petals: Tasting like their scent, the petals can be added raw to salads, or cooked to make a syrup or jelly. Similarly to rosewater, peony water made by infusing the petals in water for several hours is considered a delicacy, and the flowers and petals can be floated in punch or cocktails.

Scented leaf pelargoniums: Grown for their pleasing citrus fragrance, the leaves can add flavour to desserts, and the flowers also have a more delicate citrus flavour and work well crystallised or scattered through salads.

Know what you're eating

The RHS warns that people should be absolutely certain about what they're picking before they eat it - if in doubt, leave it out.

Many plants grown as ornamentals will have been treated with various chemicals and are unlikely to be suitable for eating in their first years, and any plants that have been treated in the garden with chemical pesticides should not be eaten.

National Gardening Week runs from Monday, April 29 to Sunday, May 5. For details, visit rhs.org.uk/nationalgardeningweek.