Protect your borderline hardy plants in autumn to enjoy them again next year. Here’s how.
Our gardens are home to some beautiful plants that struggle in the harshness of winter. The double threat of heavy rainfall and frosts makes life a real challenge for borderline hardy specimens. Yet with a few simple strategies, you can protect these plants in the autumn and enjoy them once again come next year.
Wrap up tree ferns
Tree ferns are particularly sensitive to cold weather. Stuff the crown with straw topped with polythene to prevent rain from damaging the plant. Tie up the fronds, and wrap the whole plant with horticultural fleece.
Grow edibles under cloches
Autumn-sown crops like carrots, chicory, and leafy greens can be protected in the autumn by covering them with a cloche. These are low structures made of glass or plastic, and can be easily installed over existing beds and rows of crops for over-wintering.
Feed grass roots
Lawns will stop actively growing towards winter, but you can feed them with an autumn feed high in potassium and phosphate, such as seaweed, to promote healthy root growth. Avoid using a nitrogen feed at this time of year, which stimulates green growth that will become susceptible to frost damage.
Bring in bananas
Banana plants (Musa and Ensete) thrive outdoors in the summer but should be brought inside in the winter. This is best done with container-grown specimens, but you can still protect them if they grow in the ground. To do so, cut the banana by half, install a wire frame (such as chicken wire) around it and fill with straw. Cover the frame with plastic to keep the plant warm and dry over winter. Tie up the leaves of other palms growing outdoors to protect the delicate growing point at the base of the leaves.
Borderline hardy plants in containers tend to freeze more easily than plants in the ground. If it is not practical to move the containers indoors, wrap them with several layers of bubble wrap or fleece to prevent the roots from freezing. Alternatively, plunge smaller pots into the ground to the rim, where they will remain warmer.
Bundle up climbers
Pack straw around the lower stems of sensitive climbers, such as Passiflora, and hold in place with fleece or hessian sacks secured with twine. Similarly, wrap around embryonic fruits, such as figs, with straw and fleece.
Shelter plants sensitive to damp
To protect plants susceptible to rotting, place them inside a cold frame or greenhouse. Alternatively, use pots with drainage holes and raise these onto bricks to allow excess water to escape.
Cover dahlias, cannas, and gladioli
If you have well-drained soil, you can leave dahlias in the ground, but cover the soil with a thick layer of mulch to protect against frosts. If the soil gets waterlogged, dig up the tubers and store them inside over winter to prevent rotting.
Protect beds and border by laying down a thick layer of straw or wood chips.
Brush off snow
Snow that accumulates on branches adds excess weight to tree branches, which can lead to snapping and breaking. Brush off any snow regularly.
Perhaps the surest way to keep your favourite plants past the winter colds is by taking cuttings. That way, if anything happens to the original plant, you will still be able to grow it on from the cutting. Propagate any borderline hardy plants by taking cuttings in the autumn.
Remove all the packaging from plants after the last frosts but before new growth has begun in spring. For help with protecting your plants over winter and ideas on how to incorporate tender plants in your garden, contact our garden design team here.