In California, when it dips below 30 degrees in the Central Valley, can't help to feel a bit worried about plants and frost damage. I know, I know that's a warm spell in the Winter for you fellow readers on the East Coast.
Today, I got a call from a customer wanting advice on what to do with her bamboo plants when temperatures dip below normal and the specter of frost comes around.
Here are a few tips to help plan accordingly and hopefully ease some of the anxiety:
1. Know the temperature tolerance of the bamboo variety. I'm sure your saying "Its easy for you to say!" But there is a good source to look this information. Go to www.bambooweb.info . It's a great resource that list characteristics for bamboo varieties like height, sun tolerance and temperature tolerance.
2. Be prepared. If a nighttime temperature get within a couple of degrees of causing damage or you want to protect new tender shoots on a clumping species, be ready to protect the plant. I have found the best defense is to deep mulch around the base of the plant to protect the root mass and to have enough frost blankets (sold at most garden centers) on hand to wrap up the plants. Even a good bed sheet is better than nothing. I do not recommend using plastic sheeting. Or if it happens to be a potted bamboo plant and its mobile, temporarily placing it under an eave or close to the house also helps offer protection.
3. Don't panic. Unfortunately there are freak cold snaps and sometime you can't protect your bamboo plant due to height or girth which makes wrapping impractical. If the bamboo plant does sustain damage, it will start with leaf burn (and drop) and move its way to culm damage. Here is the beautiful part of it, many many examples over the years have shown that even bamboo that is nearly frost burnt to the ground, will come back once temperatures warm in the spring. No guarantee, but it does happen more often than you think. But, for significant damage to occur like that, it takes several days of exposure. And the key to limiting damage was deep mulching around the root mass.
Pictured above is my imperfect wrapping of some newly shooting Bambusa beecheyana and a recently propagated Bambusa ventricosa "Buddha's Belly Bamboo." I wrapped them for different reasons and the temperatures aren't low enough to do any significant damage, if any. But felt compelled to "baby" them. It's overkill, but it makes me sleep better, what can I say!