This special column is being reproduced with the permission of Steve Smith, The Whistling Gardener, and owner of Sunnyside Nursery in Marysville.
That's right folks, the weather prognosticators are telling us that the month of December is going to be a cold one and more specifically we are going to experience some of the coldest temperatures in over two years. It is time to take action to protect our gardens from what is coming our way. Here's what we need to do.
First off, drain all birdbaths and fountains and hoses and that will keep them from breaking. While you are at it install those Styrofoam covers over the outside faucets.
Containers are the most vulnerable to subfreezing temperatures and this is because the whole soil mass can freeze which can kill roots. The smaller the container the more likely there will be damage so move all pots that are portable closer to the house or under the carport or better yet into the garage when the mercury drops into the teens. Cluster them together and they will keep each other warm.
If you can't move the pot then wrap the container with bubble wrap (we sell a bubble wrap that is enclosed with two layers of foil) and the actual plants with several layers of burlap or frost protection fabric (we sell that too!). I don't recommend plastic garbage bags because they can't breathe but for a night or two they will suffice.
Next, cover your broadleaf evergreens like Escallonia, Camellia, Viburnum, Hebe, Cistus, Pyracantha, rhodies and azaleas. Japanese holly, Osmanthus and English laurels seem to weather just fine. Worst case scenario if you don't cover them is that they will die to the ground and maybe or maybe not recover. Best case is that only the flower buds will be killed. Why take the chance?
Roses should have a 12 inch high cone of compost piled up around the base of the plant to protect the graft. The branches can all freeze dead but if the graft dies then all you have is a root stock in which case you need to dig it up and buy a new rose.
Most conifers and perennials should be fine in the ground unless you know they are tender. Italian cypress will burn in an arctic blast as will Wilma Goldcrest cypress.
Palms, especially if they are young, should have their trunks wrapped and the fronds pulled up and tied together to keep any snow from lodging in the crown. Hardy bananas should also be wrapped (if they are young) to a height of 3 feet minimum. If they are established then they can die to the ground and will sprout back in the spring. For wrapping both palms and bananas I use the above mentioned foil covered bubble wrap and it works like a dream.
Hydrangeas need to be covered if you want any blooms next year. The frost protection fabric comes in a bag form with a draw string and this is a slick way to protect larger shrubs.
It is sounding like this month may be one of those on again-off again periods where the fabric is on for a week and then off for a week. If you use the foil around your pots and trunks you can leave it on all winter but tops of plants should be uncovered as soon as the weather moderates. Be vigilant and prepared and your garden should fare just fine. If something does die I just happen to know a great nursery where you can find a replacement! Good luck.
Steve Smith is owner of Sunnyside Nursery in Marysville and can be reached online at email@example.com.