December Hints & Tips
Short days and minimal sunlight hours can make December feel like a dark month. Most parts of the country will see frosts and snow, and many plants will be dormant, meaning they won’t grow.
It is, however, the perfect time to plant and maintain roses, perennials and shrubs. Make the most of tidying them by turning the garden prunings into seasonal decoration.
What vegetables to plant in December
There’s still time to sow the following vegetables if you haven’t already done so:
- Broad Beans
On the kitchen windowsill you could also be sprouting seeds in a jar:
- Aduki beans
- Mung beans
Check the instructions on individual packets and use a purpose-built seed sprouter to keep them fresh. The sprouted seeds can be added to salads as a great source of protein.
You can also try growing lettuce, herbs and cress on a windowsill.
What vegetables to harvest in December
Still cropping in the vegetable patch are:
- Brussels sprouts
- Jerusalem artichokes
If very cold weather is forecast, cover or harvest any vegetables you need to see you through the icy snap whilst you can still get a garden fork into the ground.
Things to do this month
- Install a waterbutt: These collect rainwater from guttering on houses, sheds, and greenhouses. The water is slightly acidic, unlike tap water which has been treated such that its nutrient levels are different to those which plants would naturally take up.
- Build a new compost heap: One is a good start, but if you have room then two or even three make it easier to move material through the composting process.
- Clean and service your mower and other power tools.
- Clean and sharpen hand tools, such as hoes and spades.
- Clean paths and patios using a power-washer.
- Weed between paving stones using a sharp knife or pour boiling water to kill them.
- Add mulch or compost to bare soil to protect it from severe weather.
- Dig manure into vegetable beds where you plan to grow peas, beans and other hungry vegetables.
- Float a ball in the pond - the movement will help to stop it freezing over.
- Top up bird baths and feeders as needed.
- Put out extra bird food to ensure that native birds have plenty to graze on.
- Add shelter for hedgehogs, frogs, and bugs. This can be a purpose-built small structure bought from elsewhere, or a simple pile of logs, twigs and leaves. Position it in a quiet part of the garden where creatures will not be disturbed.
From the potting shed...
Written by our plant department colleague, Chris Milborne who is based at our Great Amwell centre
As another garden year passes, now is the time to reflect on this year’s garden and plan for the future.
Gardens change in time and evolve. Areas might have become overcrowded or grown a little too much! Small parts may need refreshing, larger ones may need a complete revamp.
Get some ideas together and prepare so you are ready for spring planting. To do this, have a look at your neighbour's gardens and see which type of plants have grown well or visit your local public gardens. Large gardens can still inspire ideas & planting themes that can easily be recreated on a smaller scale. Many of the National Trust sites have great winter gardens to visit!
For year-round garden interest, inspiration and colour visit your local garden centre at least once a month to select seasonal plants. Whether it’s leaf, stem, bark or flower, there are ever-changing options to get the stunning look that best suits your interests and your garden. There are plants available for every situation or aspect, whether it be a cottage garden, a hot sunny Mediterranean border or a semi-shaded Japanese style-garden. You could also create a wildlife-friendly area.
After this autumn season’s mild and wet conditions, together with the shorter days, any fine days are very important opportunities in the garden now. This is particularly important as lawns continued to grow, but were simply too wet to mow this year, and with the late leaf fall there is plenty of clearing up and tidying to do in general.
Many herbaceous plants have now died back to the ground, or have just a skeleton left behind. It is sometimes difficult to remember their former glory, but rest assured, most perennials will return in the spring season and do it all over again.
At this time of year, colour can still be found in the garden such as the bright winter stems on dogwoods (Cornus) giving you vibrant reds, green and the fiery orange of Cornus ‘Midwinter Fire’.
This is the ‘Evergreen’ season, when these plants shine out and live up to their name, holding on to their leaves for all of us to enjoy. Pittosporums, Euonymus, Camellias and Azaleas all offer a wide range of leaf colour & shape. Elaeagnus, Pieris, Aucuba and Photinia, or the architectural leaves of Fatsia japonica and its cultivar Fatsia japonica ‘Spiders Web’ all look fantastic at this time of year. Let’s not forget plants with berries, like Cotoneaster, Pyracantha, Gaultheria or Callicarpa which all offer glorious different coloured berries.
If the garden seems flat, you can add height and impact with some topiary. Try some standard lollipop-shaped shrubs such as holly, bay trees or olives (Yew pyramids would work well too). Alternatively, you could add garden obelisks and arches to display Clematis, Honeysuckle, climbing roses or Jasmine. Look out for the winter flowering varieties of these. Another option would be Trachelospermum (Star Jasmine) - this particular evergreen with highly scented flowers does best in a sheltered sunny position.
Festive flowers and plants to consider include:
- Holly (Ilex) – there are lots of options, however with some cultivars the male and female flowers are produced on separate plants. In order to get berries you will need one of each. Always check the labels to ensure you’ve selected the right variety as the names can sometimes seem a little contradictory with Silver Queen being male and Golden King female.
- Ilex Pyramidalis J.C. van Tol produces both male and female flowers on the same plant giving the red berries for Christmas. You can also find a choice of foliage from variegated silver, golden and deep glossy green. For both berries and a golden variegated foliage try Ilex aquifolium Pyramidalis Aureomarginata.
- Ivy – there is an ivy plant for every situation. You can grow them in pots, tubs and hanging baskets as well as use them for ground cover under shrubs or to cover walls.
- Helleborus Niger, the Christmas Rose - an evergreen plant that likes well-drained soil and light shade with plenty of added organic compost. The white flat-faced flowers are produced from December to February depending on weather conditions.
- Sarcococca (Sweet Box) - all of its varieties have glossy green leaves interspersed with small fluffy flowers which smell wonderful.
- Mahonia - an architectural plant with large, leathery, holly-shaped leaves. Some varieties (such as Mahonia Caress) have softer leaves but it is Mahonia Lionel Fortescue and Mahonia Charity that have the sprays of highly-scented yellow bell-shaped flowers in winter and spring. These provide an eye-catching display and are followed by blue or black berries in summer - blackbirds love these!
Other highlights include Skimmia japonica ‘Rubella’ or Viburnum tinus.
Many of these plants are great for creating colourful home-grown Christmas table decorations and wreaths!
Plant up decorative outdoor containers to go outside the front door. You can make up attractive displays using flowering shrubs such as Sarcococca or colourful Pieris, Camellias, Heucheras, evergreen ferns or conifers. Add winter flowering heathers, violas, primroses or pansies and ivy to trail over the edges. You could also use the colourful stems of Cornus and any gaps could be filled with pot-grown snowdrops, crocuses or daffodils.
If conditions allow you can dig over and prepare the soil for next year's planting. The quality of soil can easily be improved by adding garden compost, soil improver and farmyard manure. These all contain the necessary beneficial nutrients for good plant growth. Keep in mind the saying ‘feed the soil, feed the plant’.
It’s still not too late to plant ornamental trees, fruit trees, soft fruit and roses.
To protect plants that are susceptible to the cold (e.g. Agapanthus, Crocosmia, Nerines) apply a good mulch. Raise any planted tubs and containers onto feet or bricks to improve drainage in wet conditions. Insulate containers with bubble wrap or fleece to prevent compost from freezing, which is especially important for evergreen plants. These need moist soil conditions to allow them to continue growing (albeit at a slower rate) throughout the winter period. Frozen conditions can lead to foliage desiccation or drying out. This protection also helps to prevent pots from cracking.
Now is a perfect time to prune apple and pear trees, removing any dead, diseased or crossing branches to maintain an open wine glass shape. After pruning the fruit trees, use the twigs next year for pea sticks or supporting broad beans. Alternatively, make them into supports for herbaceous perennials to give a natural look.
Prune grape vines before Christmas - this helps to prevent bleeding as the new sap rises in spring.
Top tip - clean pruners and secateurs between plants to reduce risks of spreading diseases or infections!
Start thinking about next year’s seeds, whether you’re growing vegetables in the garden or allotment, or flowers in tubs or borders. Try and grow something a little different each year, look for a completely new plant or go for a different colour scheme.
Grow a few herbs on the kitchen windowsill, they may not have exactly the same flavour as when grown in summer sunshine but they’re still tasty and very useful.
As we escape inside to avoid the worst of the weather, we should start thinking about Christmas houseplants. A classic is the Poinsettia, a plant with a colourful history originating from Mexico where it grows as a large shrub or small tree. It was grown by the Aztecs for use in medicines and as a dye.
As far back as the 17th century it was used by Franciscan monks as a Christmas decoration as it is today! It was named after Joel Robert Poinsett, a renowned botanist and US minister in Mexico. He introduced the plant to the USA in the 1820s. Here in the UK, it has, over the last 60 years, become an iconic part of Christmas. The bright colours come from the leaves and bracts.
As well as the traditional red, they are now available in pink, cream, white and marbled effects. The actual flowers are small yellow tufts in the middle. To succeed, Poinsettias need bright indirect light in a warm room with an even temperature, so avoid placing them near radiators or in a cold draughty position. Keep the compost moist, preferably using tepid water to avoid root shock.
There are a wide range of orchids available with flowers that can last a month or more. The Phalaenopsis (or moth orchid) has arching spikes of large flowers in pink, white and cream colours, with repeat flowering virtually year round. Other orchids available include Paphiopedilum, the “slipper orchid”, Dendrobium, the “cane orchid” and Cymbidium which has wonderful large, waxy, flowers that last up to 8 weeks.
Originating from the forests of the Himalayas, China, Japan and Korea, orchids flourish in a kitchen or bathroom with good light. Their pots should be stood in a saucer of damp pebbles to increase humidity. They should be watered with rain water or boiled tap water (cooled) as they don’t like chlorine or chalk. Be careful not to overwater.
Other traditional favourites also include indoor Azaleas, Christmas Cacti and Cyclamen. This year perhaps try an architectural plant such as a palm or Jasminium polyanthun, a climbing plant with pink buds opening to white tubular highly scented flowers.