The first inkling I had that unusual edibles would catch my eye at Hampton Court this year was the sight of deep red Calycanthus flowers around every corner. As soon as I entered the show, there was Calycanthus ‘Aphrodite’ in Evolve: Through the Roots of Time Garden, beautifully set off by the predominantly green foliage of the Jurassic and Cretaceous Periods, then more specimens by the entrance to The Countryfile Garden, in The Family Garden and outside the mirrored meadow-room of Apeiron: The Dibond Garden.
This aromatic shrub is most often grown for its glossy foliage and single elegant flowers, but its bark was traditionally dried in indigenous American cultures and used as a substitute for cinnamon and allspice. The flowers and seeds of both Calycanthus florida (Carolina Allspice) and Calycanthus occidentalis (Californian Allspice) are poisonous and the Plants For a Future database advises caution when using the bark due to the plant’s toxic components, but James Wong includes Calycanthus floridus in his Homegrown Revolution, it has been featured in The Guardian by Lia Leendertz as producing an ‘edible spice’ and Calycanthus ‘Aphrodite’ has also been planted in this year’s RHS Grow Your Own Garden along with other shrubs with edible parts.
Ugni molinae ‘Heritage Ice’ (Chilean Guava)
Regular readers will already know of my fondness for the Chilean guava. I have Ugni molinae ‘Ka-pow’, just one of the cultivars on display in the Plant Heritage section of the floral marquee. Dr Gary and Dr Maria Firth hold the National Collection of Myrtaceae which includes collections of myrtle, luma, Chilean guava and lophomyrtus and this year their Ugni molinae selection includes ‘Kapow’, ‘Butterball’, ‘Variegata’ and ‘Heritage Ice’.
‘Heritage Ice’ has variegated leaves speckled with cream and Gary told me it isn’t prone to reverting, unlike ‘Variegata’. With such attractive foliage, delicate white flowers and delicious, aromatic fruit in October – a time of year when sweetness and perfume are fading away with the memories of summer – this is a shrub which deserves to be more widely grown.
Zanthoxylum (Szechuan Pepper)
After helping to plant the Foraging Forest Garden at the RHS Autumn Show last year and showing visitors around the installation, I became fascinated with the different Szechuan peppers around the garden. I bought a Zanthoxylum piperitum earlier in the year and it has been an unmitigated failure so far. When I planted it out in the garden I noticed the developing leaves kept disappearing overnight, leaving me week after week with an unprepossessing stick poking out of the earth. Deciding that slugs were the culprits, I moved it back into a pot away from the molluscs, but it is still sulking and refusing to produce leaves (although it is still alive – just!)When I saw the Zanthoxylum piperitum in the RHS Grow Your Own Garden I felt a certain amount of pepperish envy. Beryl Randall, who writes the gardening blog Mud and Gluts, was helping to plant the garden and she brought along her own Szechuan pepper to add to the edible display – doesn’t it look healthy?
To find out what I’m doing wrong I spent a while chatting to Fiona Blackmore and Chris Smith at Pennard Plants about their growing collection of Zanthoxylum. They have 11 species so far including winged prickly ash (Zanthoxylum planispinum) – a very spiny Nepalese form which is is one of the ingredients in Chinese ‘Five Spice’, lemon-flavoured Zanthoxylum simulans and my favourite, the Japanese pepper (Zanthoxylum piperitum ‘Purple Leaved’), which forms one of the main ingredients in the Japanese blended spice shichimi. As well as collecting the berries of these peppers as a spice, the leaves can also be used in salads and as a flavouring.
The general feeling was that my problem had been slugs and the plant now needs some TLC (better growing medium/seaweed fertiliser) to help it recover and come into leaf. If this doesn’t work though, I’ll not be too sad. It will be a good excuse to buy a couple more peppers from Pennards and this time I’ll follow Beryl’s example and keep them in pots.
Broussonetia papyrifera (Paper Mulberry)
This Asian shrub in the mulberry family was a new one for me when I came across it in the RHS Grow Your Own Garden. Its primary traditional use was for making paper in China and handcrafted washi paper in Japan, and it has edible fruits and leaves (when cooked). It is classed as an invasive species in some countries like Uganda, Pakistan and Argentina, and has allergenic pollen.
The fruits, which develop if the flowers are fertilised, have a similar look to the mulberry with a cluster of drupes creating a spherical pom-pom which ripens to orange or red. They are apparently best eaten fresh and have a sweet taste. The paper mulberry can be grown in most areas of the UK, but it’s classified as H5 by the RHS (hardy down to -10/-15) so might suffer in cold winters. It also has a suckering habit – one of the factors which can make it invasive in warmer countries. I’m not sure I’d grow it exclusively for the fruits as I imagine the crop would be fairly small, but the dramatic foliage creates impact and in areas that don’t have repeated hot summers the plant remains shrubby, perfect for the back of a sunny border.
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