How to protect exotic plants from winter frost

Visit your local garden centre and you'll find masses of exotic plants rubbing shoulders with more traditional trees and shrubs. Over the last few years, tree ferns, bananas and bamboos have become must-have plants thanks to their architectural shape or showy flowers.

However, many of these plants are ill-equipped to survive a cold winter as they originate from tropical climates - to ensure their survival, give the plants some protection and they'll coast through winter, ready to burst back into life in spring.

Tree ferns

If your garden is protected or you live in a mild area where frost is unlikely, all you need to do is wedge a handful of straw in the top of the plant to protect the crown.

In exposed gardens, give ferns greater protection to prevent foliage from browning off and dying. Pull fronds up vertically, tie together with twine then wrap with horticultural fleece. Hold securely with more twine.

Palms

With flexible-leaved varieties, such as cordyline, pull the leaves up into a point and tie together with twine to protect the central growing point. Cover the leaves with horticultural fleece held together with twine, or even clothes pegs.

Use the same method for stiff-leaved varieties, but wear gloves to protect your hands. If the leaves are too rigid, use straw and fleece for protection.

Succulents in pots

A cold snap will swiftly turn cacti and succulents to mush, so if they are a modest size, move them to a warm greenhouse, porch or windowsill. Large plants are trickier.

Wrap leaves with horticultural fleece and, to prevent winter rain from rotting roots, build a shelter around the pot - put a stack of bricks, taller than the plant, either side and pop a sheet or marine plywood or rigid plastic over the top.

Banana trees

To protect bananas growing in the ground, first cut off all the leaves so you end up with short stubs.  If the trunk is thin, stack lengths of flue liner (from DIY stores) on top of each other, filling the gap between the pipe and trunk with straw. Large trunks need more substantial treatment.

Put a ring of chicken wire around the stem and hold together with cable ties - stuff the gap with straw. For very tall bananas, add another ring of wire to the first. Put a curved roofing tile or a plastic bag with holes punched in it on top and spread a thick layer of bark or compost around the base.

Tender bulbs

Chop back leaves and flower stalks of cannas, pineapple lilies, dahlias and other tender bulbs growing in pots, aiming to leave about 3cm of growth.  Then, put in a greenhouse, porch or shed over winter.

If you live in a mild area, tender bulbs growing in the soil should be OK with a thick layer of bark or garden compost over the top. If you're nervous about leaving them, cut back the leaves, lift with a fork and clean off the worst of the soil. Allow to dry then store in trays of clean compost until the spring.