We have many exotic plants growing at RHS Garden Wisley, especially along the Mediterranean Walk and south side of Battleston Hill - including bananas, palms, cordyline, succulents and cacti. It's a big task making sure they are protected and ready for winter.
Straw and bananas
The biggest task is protecting the bananas. Japanese banana, Musa basjoo, has roots that are relatively hardy, but the stems are tender and we want to keep as much stem as possible for bigger plants next year.
We cut the leaves off, then wrap each stem in a layer of horticultural fleece before placing cages around them and stuffing firmly with straw. Some of the structures reach over 3m (10ft) tall! In total we use about 30 bales of straw; luckily I have an army of volunteers and students to help me, to whom I'm very grateful.
Straw is a great insulator and can be used to protect a variety of plants. We place it into the centre of palms such as Chamaerops humilis AGM, Jubaea chilensis and Brahea armata before wrapping a few layers of fleece or hessian around the whole plant. Although many of these palms would survive a British winter unprotected, the Mediterranean terraces are exposed to bitterly cold prevailing winds so we take precautions.
We also press a few handfuls of straw into the crowns of our tree ferns (Dicksonia antarctica AGM), which is enough to protect them due to their more sheltered position. Colourful cordyline cultivars such as 'Torbay Red' tend to be less hardy than the species, so we tie up the leaves and wrap the whole plant in several layers of fleece.
Waterproof and windproof
A new project for this year is a steel framework that has been created to support a plastic cover over the succulent and cacti terraces, which contain plants such as Opuntia, Agave and Aloe. These plants are some of the hardiest of their kind, but they don't appreciate the combination of cold and wet weather so we give them a waterproof and windproof covering.
It's taken some experimenting, but so far so good – the polytunnels are taking shape. This year we are using a thicker grade of polythene, which we are hoping will weather the storms – and survive the spines of the plants – better than last year.
Hopefully this has inspired you to try something new in your garden. It's amazing how a little fleece and straw can open up new planting possibilities, plants you wouldn't normally think of growing outdoors in the UK.
RHS Advice: Wrapping tender plants to overwinter
Find out more about protecting bananas over winter