Sudden bouts of snow and frost can be a problem for gardeners and their plants as waterlogging can cause long-term damage to root systems. There are plenty of fairly easy steps that gardeners can take, in both the short and long-term, to minimise damage to garden plants. Perhaps the most important action is to mitigate waterlogging by adding organic matter before planting and mulching generously.
Short-term remedy
- Cover smaller flowering plants with a cloche or fleece before frost to protect blossom against frost damage.
- Waterlogged plants in pots should be laid on their sides. Later, if they seem to have been damaged, be prepared to repot into smaller pots using fresh compost after removing dead and rotting tissue.
- Try to keep off saturated soil until it is workable to avoid worsening the conditions.
- Prune out frost damaged foliage when effects of freezing begin to appear.
- Apply a dressing of balanced fertiliser in the spring and mulch over the root area.
- Foliar feeds during the growing season may help improve leaf colour and encourage new root growth.
- Water thoroughly in dry spells as plants will be more susceptible to drought stress following waterlogging.
Long-term prevention
- Working organic matter into beds can help to improve drainage and aeration and ridging vegetable plots will help soils drain and warm up in spring.
- Repot long term container plants every other year with fresh compost that has an open structure. Add extra grit if necessary to make compost free draining.
- Plant woody plants on ridges or low mounds to ensure good drainage around the base of the stem.
- Choose willows, poplars, dogwoods and elders for soils that are wet for prolonged periods.
- Where winter waterlogging occurs frequently, it may be worth investing in drainage systems, assuming you have somewhere for the surplus water to go.
- Use a very thick mulch of organic matter around particularly susceptible plants. This creates an aerated area between sky and soil where roots thrive even in wet conditions.
Frost and, more specifically, alternate freezing and thawing can destroy plant wall cells, often killing tender plants. Flowers, shoots, buds and leaves of hardier plants may also blacken or become distorted. In severe frosts the bark of woody plants can split. However, gardeners should not be put off by frosty spells - most plants cope very well. There are some steps to take which can lessen the risks of plant damage.
- During cold snaps, identify the warmer and more sheltered spots, such as against walls and beneath trees, as likely places for the more tender plants and note ‘frost pockets’ for the more hardy ones.
- Try to choose the right plant for the right place - the free online RHS Plant Selector can help you here. Note what grows well locally and then experiment with different introductions. By choosing plants that suit the site you will avoid endless work and disappointment.
- Some exotics will need wrapping and protecting in the winter months.
- There are some plants which will withstand almost any weather and will help add structure and shelter to the coldest garden while you work out where the less robust plants will thrive best: Philadelphus coronarius 'Aureus' AGM; Photinia villosa AGM; Cornus mas AGM; Corylus avellana 'Contorta' AGM; Rhus typhina AGM; Cotinus coggygria AGM; Rosa xanthina f. hugonis AGM; Euonymus alatus AGM; Viburnum carlcephalum AGM; Kalmia latifolia AGM; Kerria japonica 'Pleniflora' AGM.
In very cold areas tougher plants will be needed as well as deep mulching. Remember that it is much less cold beneath trees and some plants thrive well here in the cool, moist conditions such as primulas.