So. 2020 is just about done, all bar the shouting. Not a year anyone in the world is ever going to forget in a hurry. But Glory Be! At LEAST it’s meant that millions more people love and appreciate plants and gardens now. Let’s escape the knotty and stressful confusion of who’s allowed to go where, when and with whom over Christmas, and get stuck into tasks like protecting our tender plants, tidying up hellebores, and conditioning Yuletide foliage………
Okay, so there’s no pretending it won’t happen now – we WILL all get some perishingly cold weather at times before this winter is out. Some more than others, obviously (sorry, Caroline!) but it’s gonna get real nippy for all of us.
There are several ways you can help your more tender plants survive through icy snaps so give some serious thought to which ideas you think will work best for you:
Wrapping is a good option for large pots, banana plants, yuccas, olive trees, pelargoniums. etc. Tie bubble-wrap around the pot – I’ve even persuaded Laura to look after her Callistemon in this way, as you can see from the feature photo! But don’t use bubble wrap around the plant itself as this can lead to problems with rotting; securing horticultural fleece around the actual plant is a better option. Make sure that your pots are well-drained in winter, by the way – it’s often a combo of wet and cold that kills plants in the UK, not just the cold.
A tender plant out in the garden – a tree-fern, for instance – would hugely welcome a simple frame made round its trunk with canes and chicken-wire, which you then stuff with dry straw and cover with fleece.
A 5cm deep mulch of straw, leaf-mould or compost around some plants offers them excellent protection from penetrating frost at their roots. Deciduous Agapanthus and Melianthus are two that spring to mind.
Lower-growing crops or tender perennials are best protected by cloches or little tunnels of fleece. It’s not too difficult to rig up a simple frame, or you can buy ready-to-use cloches of all types from most garden websites.
Many people these days leave their dahlias in the ground over winter covered by a thick mulch, but if you’re unsure whether that provides enough protection for your gorgeous darlings, it’s better to lift and store the tubers over the winter. Wait until the first frost has blackened the leaves (probably already happened in most places though not here on the southern seaside yet). Then dig up the tubers carefully, clean off the soil and store them in a box in a cool, dry frost-free place. You’ll pot them up in spring and get them sprouting again. Lift cannas in the same way, but these need to be kept moist over the winter rather than dry.
Alpines are those exquisite creatures whose perfect blooms can blow your mind as they sit and glow in terracotta pans in somewhere like the RHS Wisley cold glasshouses. I’m thinking of treasures like the low-growing campanulas, sedums, sempervivums, Verbascum x ‘Letitia’, Aethionema ‘Warley Rose’ etc.
They make delightful additions to rock, scree or gravel gardens – anywhere in fact, that’s sunny and free-draining. And contrary to expectation, many are very easy to grow, making them great for new gardeners.
Seed-sowing is not often undertaken in December in the UK, but this is one group of plants that benefit from being sown at this time. They have a deep-seated aversion to wet, soggy soil, so the compost for your seeds must be VERY ‘permeable’ – lots and lots of fine grit or coarse sand is needed in the mix. Use ericaceous compost if you’re sowing lime-haters like trilliums, certain kinds of Primula, etc. Do a little check by watering it without the seed in it, to make sure that the pot drains very quickly.
Sprinkle your seeds over the surface and then finish the pot with a 1-2 cm layer of grit, and water it. If the seeds are very small, put the grit in first, sprinkle the seeds on the top of that layer, and hand-mist some water onto it.
Now here’s the thing about these kinds of seeds. They need protection from the wet but NOT the cold. In fact most of them positively need the cold to prompt germination (they are not called ‘Alpines’ for nothing!). So keep the pots outside in a cold frame, cold greenhouse or with a sheet of glass or a plastic sheet over them to keep out the rain but not the chill. Make sure they don’t dry out completely (check once a week) and otherwise, just let them get on with it.
There’s nothing like getting a few seeds going to make you feel cheerier about the future, is there!
- I was waxing lyrical in last week’s blog about Helleborus niger in a Christmas pot, but you could also help along any Helleborus orientalis that you have in the garden. Cut off their old leaves now which can harbour black moulds and look horrible against the new growth. It clears the way for the lovely buds and flowers to start appearing in February and March.
- If you’re bringing in foliage to decorate the house for Christmas, remember to split the stems and branches and give them a good overnight drink in a bucket of water first. Cut them again before you arrange them and they’ll be better able to withstand the warmth of the house. They wouldn’t say no to an occasional mist of water either.
- The depths of winter is a good time to have a look at any trees in your garden that have low branches, and consider ‘lifting the crown’. It makes it easier to enjoy the shade beneath, get the lawn mower round, or plant woodlanders beneath. I talked a little more expansively on this topic a while ago. Link at the bottom.
A few tips about crown-lifting are in this blog
NB If you’d like to order a copy of ‘A Plant for Each Week of the Year’ written by plantswoman and our columnist Louise Sims, there’s still time to get it for Christmas – we’re now sending it out by Royal Mail First Class.
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