How to protect your plants in winter
by Drucilla James
Baby it’s cold outside …and although many plants can withstand changing temperatures, now is the time to protect your most precious plants from the damage that can be caused by flood, frost, drying cold winds and even heavy falls of snow.
The New Year usually brings the worst of these conditions including the added danger of a freeze after a mild period when plants can be triggered into early growth and then suffer serious damage.
The key advice is that old adage ‘Prevention is better than cure’, or in this instance, the loss of a prized gem. This is a round-up of some simple precautionary measures you can take:
Things you’ll need:
- Horticultural fleece: this is fairly inexpensive, quick and easy to use, especially for overnight or a few days protection from frost. You can double up the layers or more.
- Bubble wrap
- Straw or hay
- Shredded paper
- Bracken (you may wish to check on the latest thinking about this material and any possible health risk).
- Avoid high nitrogen fertilisers late or early in the season as they encourage plants to produce sappy soft growth which is vulnerable to damage. Using potash will encourage strong growth.
- Take cuttings of your greatest treasures.
- Leave side shoots on tender plants, if damaged they can be pruned back in the spring.
- Prune back geraniums, such as the scented varieties, keeping a good core of the plant. Then wrap up in a parcel of horticultural fleece stuffed with hay, straw or shredded paper and store in a shed, garage or cold frame.
Protecting from frost
- Keep off the grass- frozen lawns are easily damaged by being compressed when frozen.
- Newly planted specimens can be lifted as the soil freezes and will need careful attention when re-bedding.
- Plants in containers need protection with a sheet of fleece when temperatures fall to about 5 Celsius.
- Containers themselves need wrapping in bubble wrap or fleece when temperatures fall to freezing and below; this prevents the roots freezing and the plants being unable to take up water.
- Most shrubs should survive the harshest of conditions we face in a normal winter in this country by covering them with a double sheet of horticultural fleece. Those that flower on last year’s growth will need those branches to be especially protected.
- Climbers such as Black-eyed Susan (Thunbergia), glory vine (Eccremocarpus) and passion flower (Passiflora) need to be covered with fleece if temperatures fall below 5 Celsius. They also need straw, shredded paper or hay at their base, covered with fleece.
Protecting from heavy rain
- After putting grit around them, tender perennials should be mulched to a depth of 5 cms/2 inches to 15 cms/ 6 inches to keep them warmer and to stop water-logging which can cause rot.
- Flowers especially Hellebore flowers can be protected from soil splashes during wet weather by placing straw around their bases.
- Waterlogged soil should not be walked on as this compacts it and increases the potential for rot. A plank or something similar should be used to stand on.
Protecting from winds
- Young trees and shrubs should be checked for root rock. If they have started to move, they need firming in again.
- Evergreen shrubs and trees may need protection against the drying effects of wind. Young or small conifers can be surrounded with cut conifer branches stuck into the ground around them and angled to cover the plant.
Protecting from snow
When snow falls on the plants, it acts as an insulator which is fine as long as it does not get too heavy and break branches, especially in windy conditions.
- Evergreen trees and shrubs can be freed of accumulated snow before it has chance to become wet or heavy or freeze solid by shaking branches gently or pushing them upwards with a broom or rake.
- Some conifers and hedges may need help to stop their branches being forced outwards thus opening them up. These need to be tied so that the snow cannot force the stems apart and snap them or destroy the shape of the plant.
”The special ones”: tips for the protection of particular plants
These need to be mulched to a depth of 15 cms/6 inches.
Individual plants need to be covered with a sheet of glass or clear perspex weighted so it is not blown off by the wind. Pots need to be covered in the same way ensuring there is a gap left for ventilation. Large areas need a frame with polythene stretched across it, again raised so that there is some ventilation.
Leaves and side shoots should be removed. Straw can then be packed around the stem as thickly as possible and then surrounded with a double layer of fleece pinned to stakes driven in around the stem to form a tube. The whole stem needs to be covered.
Figs are hardy, however the embryonic fruit needs protection from frost. Sheets of fleece will give protection from light frost, but multiple sheets will be needed if temperatures plummet.
Phormiums, Cordylines and palms
For these you need to tie up the leaves to protect the crowns.
Fronds should be folded up and straw placed over the crown and then a polystyrene top secured in place with double-sided carpet or duct tape. This will cause rain to run off rather than enter the crown thus reducing the risk of rot. Straw can then be packed around the stem and held in place with a double layer of horticultural fleece tied securely so it resists any winds. After laying grit around the root, a layer of mulch should be added.
Keep checking the weather conditions in your region and consider how these are affecting the microclimate of your garden.