Love me Tender!
Many thanks for your recent enquiry concerning the winter protection of your Jasminum, Bougainvillea and Camellia.
Let’s start with the Jasminum and the east-facing wall the plants are trained up is certainly going to be a bonus when it comes to frost protection. The brickwork will act like a mini-storage heater as well as giving you an easy fixing point for the fleece although to make the most of the heat retaining properties of the wall, you’ll need to remove the cover during warmer days. I’d certainly advise covering the plants right down to ground level as this will trap any warm air rising up from the soil – and a mulch around the crown and root spread will help protect these vulnerable areas.
As for when to start covering up; it’s really a case of keeping a close eye on the weather forecast and once a hard frost is forecast, unravel the fleece! Jasminum humile ‘Revolutum’ is reputedly hardy so light frosts shouldn’t be a problem but no one knows their plants better than the gardener/homeowner and if past experience has shown you that these plants don’t like the cold, cover them up.
Your potted Bougainvillea is slightly easier to tackle as if you’ve got the interior space, it’s always safer to move susceptible plants indoors. Choose an airy, well-lit room and keep the plants moist but not waterlogged – a major cause of outdoor potted plant winter demise is the roots drying out whilst inside.
Again, if you have the space then move the Camellia inside as well but these plants are far hardier than Bougainvilleas and usually flower very early in the season, you may want to ‘spot protect’ with fleece or a fitted fleece jacket when appropriate. The roots of potted plants are particularly at risk of frost damage and frozen roots often leads to the death of the plant so don’t neglect the pots – cover with bubble insulation or use the fleece jackets to protect.
Finally, I’m not an advocate of zipping up plants and leaving them for the winter as in my experience it is advisable to remove any fleece or other protective material from the plant periodically throughout the winter as this will help to prevent a build up of humidity, which of course can encourage rots and other diseases to develop.
Of course, this needs to be done when a frost is not forecast and temperatures are high enough for the plants to be comfortable, so it really makes sense to only cover the trees when cold weather is expected – and watch the wind too, as a biting winter northerly can do almost as much damage as a frost!
And that’s a quick summary of how to protect your plants this winter which hopefully will prove to be of help. Many thanks once again for your enquiry and the best of luck with overwintering your plants – let’s hope we ‘enjoy’ a mild winter this time around!