What to do in the garden in December

Winter gardening videos

How to overwinter tender plants and how to overwinter seeds so they are good for the next year

Prevent Wind Rock in Roses

Wind Rock in roses can be a problem in the winter, especially for the taller varieties.   Strong winter winds can cause the rose to shift about in the wind, which creates a gap between the stem and the soil. This gap can get bigger as the plant moves about in the wind, which allows water gets in around the stem, and then to freeze. It is possible to reduce the plant's vulnerability to "wind rock"  by pruning the stems down by around a third.  Only prune roses during a mild spell otherwise it is possible the frost may damage the growth bud below the cut and cause die back of the stem. 

Ice damage to water butt

Prevent water butts freezing & Protect tender plants

If there is a prolonged spell of low temperatures and freezing weather,  it is possible for the water in a water butt to freeze, and this expansion will cause the plastic to fracture as in the image left. This is what happened in my garden during a spell of very bad weather.  If severe weather is forecast, consider draining the water butt, otherwise it can be an expensive mistake.

Winter protection  is needed for non hardy plants, follow this link for an explanation of Frosty Hardy. Popular examples of shrubs which are not fully hardy are Olive trees, a Mediterranean shrub sold in various retail outlets and whilst Olives, especially once established, will tolerate a significant level of cold, but not a prolonged spell of low temperatures which we often experience.  Olives are ** hardy as is  Laurus nobilis, common name Bay, both of which are increasingly grown in containers. Some varieties of Agapanthus,  Escallonia,  Herbs  are aslo not fully hardy, and need winter protection..  

To ensure winter survival, it is best to bring the plants in under glass and raise the container so it is off the ground by inserting feet or raising on bricks.  If overwintering outside, it is important to wrap the container with something insulating, bubble wrap, Hessian, or old jumpers and if it's going to be freezing, cover the plant with a fleece. It is equally important to remove the fleece when the cold spell finishes to ensure the plant gets plenty of air circulation. Plants covered all winter, or covered up for too much often get damp which can cause rot. 

Forget me nots stream side

Weed Borders and Thin out Forget-me-nots

Winter can be a good time for weeding. I often find that the battle against the weeds has been lost by the end of the summer, especially as plants are so lush the weeds are hidden and only fully revealed as the time comes to clear the borders. After a frost is a good time to weed; the ground yields the weeds more easily.

It is good to look forward to Spring and  Forget-me-nots  (latin name Myosotis)  often get a bad press as a zealous self seeding cottage plant. Bad press or not, forget-me-nots can offer much welcomed early spring colour and look fantastic with spring bedding and in a natural setting alongside a stream in a semi wild patch.  

For the best spring display of Forget-me-nots, during a mild winter spell thin out the plants. Forget-me-nots do self seed a lot, and if they are growing too close together, Forget-me-nots are prone to mildew which can spread to adjoining plants. One year I didn't thin them out, and they overcrowded other plants, and damaged a clump of Hellebores. It really is important for the health of the forget-me-nots and the surrounding plants that you thin them out in late autumn or early winter.

Prevent Damage to lawns

Winter damage keep off the frozen grass

It's really true that walking on the frost frozen grass causes damage. When frozen, the leaves become brittle, and will not yield to pressure, which means when trodden on they snap and break.  The image left shows where grass has been walked on, leaving brown marks where the grass is damaged, which look unsightly into the spring and the damage will make that patch more susceptible to disease.

Given how hard it is to create a decent lawn its worth resisting walking on it during the very cold weather.

Watch out for Snow damage to Shrubs

It is a good tip to knock snow off shrubs when there has been a heavy snowfall.  I used to think this advice represented an abundance of caution, making gardening work for work's sake, until we had a really bad winter with heavy snow and it badly damaged several shrubs. All shrubs are at risk, but those with the more open crowns are most at risk. What happens is the snow piles into the open centre of the shrub which forces the branches out until they snap.  Also, the snow weighs down the branches, freezes them to the ground, bending branches over until they snap.

elaeagnus branch

Heavy snow will snap the branches of even mature shrubs. If this happens, all you can do is prune the shrub, but it may never regain its shape if severely damaged. A good tip for snowy weather: get out there as soon as you can with a soft broom and brush snow off the tops and loosed branches tied down by snow which will save the shrub, and money if you have to replace it.  

The Elaeagnus in this image is from my garden and was devastated by snow damage, and many branches had to be pruned and cut away. The sheer weight of the snow had bent the branches, some touched the ground and held down by the snow, and more snow. Finally the branches snapped, even mature branches,  leaving me with no choice but to cut them off completely; snow pruning a novel experience. Snow is far more destructive than it seems. The short video below shows the effects of snow and how to deal with it to avoid problems.

Hellebore black spot

hellebore with black spot

Hellebores can look unsightly with black spot. It is fine to cut off old leaves from Helleborus, which produce flowers from ground level, to expose the flowers and remove the leaves infected with leaf spot. It is best not to compost the removed leaves because of the black spot infection.

Hellebores are a lovely late winter and early spring flowering plant which are easy to grow and will tolerate some shade.

Tips on growing Helleborus and images of many varieties of Hellebore 

Page last updated 23.12.2022