How Does Your Garden Grow?

Louise Grabell

December already? How did that happen—I was just enjoying my zinnias and marigolds. LOL – nights are getting colder and holiday hams are getting cheaper. Every store is full of plants to brighten your home: poinsettias, cyclamens, amaryllis, Christmas cactus, etc. This is also the time of year when those of us growing citrus begin to worry about frosty nights. And it’s also a concern for those growing Peruvian pear and fence post cacti.

It’s important for you to pay attention to the weather reports if you own any frost/freeze-sensitive plants. You can predict the nighttime low temperature for any day by merely subtracting 30 degrees from the daytime high temperature. Problem is that we are more than 1,000 feet higher than Tucson airport where the weather reports originate. The result is that we average at least five degrees cooler than the temperatures reported on the radio or TV. We will hit the freezing point here much sooner and more frequently than locations in town; however, the length of time that the coldest temperatures will last on any given night is only a few hours before sunrise and this is not usually damaging to most plants. If you’ve got a frost-sensitive beauty in your yard, it’s not too soon to prepare for those cold nights ahead. You can purchase frost cloth at any hardware store or garden center. They are typically 12 feet x 12 feet. It’s enough for a large shrub/small tree. I’ve been known to sew two of them together to make one large enough to cover my lemon tree.

It’s OK to cover lemon and lime trees now and leave them covered until the end of February. Same for the cold-sensitive cacti. Saguaros do not need to be covered. They live here! They know about the cold! Mature grapefruit and orange trees do not need cold protection. When covering any shrub or tree, it is important to place the frost cloth properly. Do not wrap the cloth around the tree and tie it up like a Popsicle! The frost cloth should hang straight down to the ground and be secured at ground level with ties or rocks in such a way that the bottom is open to the radiated heat from the ground. Basically, you want to make a tent out of the frost cloth. I have found that putting an old-fashioned incandescent bulb inside the tent at night will provide enough heat on the coldest of nights to protect my lemon tree from freezing.

Your Master Gardeners invite you to visit their new website: for all up to date information and events for our community. Garden questions? You can reach our very own Garden Helpline by calling Pat at 407-6459. Your phone call will be forwarded to a Master Gardener Volunteer who will assist you in the solution of your problem. Your SaddleBrooke/SaddleBrooke Ranch Master Gardener Volunteers are here all year round to assist with any plant or landscaping problem.

Remember, nothing brings more tranquility to the heart than a beautiful garden.