About USDA Zones and Succulents

One of the critical items to consider when growing succulents is freezing. After all succulents are roughly 80% water content so that freezing is likely to have pronounced affects on these plants. USDA zones provide a good first guess at winter lows in your area. The zones are divided up into 5 degree F bands. There are some other mitigating factors you might want to consider as well.

  1. Are you in an unusual microclimate area in your neighborhood? For example here at Serra Gardens our  USDA zone is 10a 30-35F. We have customerr in lowlying canyons within the same zip code area complaining of much colder temps and ruined plants. Closer to your house is a microclimate also providing a couple of degrees of warmth.
  2. USDA zones wont tell you much about heat extremes. Some plants can tolerate extreme lows but dont do well under high temp. A case in point are sempervivums. They can do very well in the midwest winter conditions but will burn up under full summer Southern California exposure. They would like to have some broken light in the summer.
  3. USDA zones wont tell you much about shade tolerance. For example shade many aloe and agaves like to grows in full sun. Low light will “explanate” them. (This is the agave equivalent of etiolation. the leaves spread out.)
  4. Every ten years or so there is a delightfull catastrophic freeze which ruins a lot of your plants. Theres not much you can do about this except try and cover ypour plants if yoiu can see it coming.

So the USDA Zones an approximation and not exact. They help reduce your plant losses and help you make decisions.

Here are some additional things we have done here at Serra Gardens to help minimize freeze losses…

  • Put plants in a few areas of your yard. When a freeze comes it usually wont get them all (Hopefully). If you live on a slope the lower areas might get colder. The cold air drains like water.
  • Put plants near a rock or wall of the house. The driveway heats up too and could be good place. Some times just a couple of degrees of protection is all you need.
  • If your watching the news and you see The Arctic Blast coming again then you’ll need to rush home and try and cover your plants. Here at Serra Gardens have purchased a role of Freeze cloth (The good stuff that should give about 4 degrees of protection). We just cover our most sensitive plants and everybody else is on their own. In the Untimely absence of freeze cloth you can use paper, leaves, or light fabric. (Plastic will burn your plants if it touches them.)
  • You can also water your plants. Not good if your in a drought area.