With the threat of cold this coming weekend, some plants could be damaged…you may want to protect them. This can be achieved in several different ways.
- Pile wood chip mulch over a plant. This can be held in place by a nursery planting container that has had the bottom cut off, thus creating a tube. Other materials can be used in place of wood chips.
- Use a thermal blanket or sheet to cover plants. These can be purchased relatively cheaply at nurseries and hardware stores. Pin to the ground using large rocks, or better yet, use landscape fabric pins.
- Use old-style incandescent-bulb Christmas lights. This is especially useful on trees. They radiate some heat, usually enough to make a significant difference in reducing damage and increasing survivability.
Both the wood chips and thermal blankets work by keeping “heat” from the ground on the plants…our soils never freeze, so keeping that warmer air around the plant can make a huge difference. This is one of the benefits of leaving leaf “litter” (think of it as “leaf mulch”) at the base of plants like Lantana or Aloe.
Cold spells where temps drop below freezing are part of our normal weather patterns. It is when temps drop down to the mid-20’s or below that I start to worry. The longer it stays cold, and the less the day warms up following each cold night can make a big difference. Temps are projected to drop into the mid-20’s and rise only into the low-40’s for 3 or 4 days, so damage could occur.
Among the plants you might want to protect are:
- San Pedro cactus
- Smaller (<10″ diam) Golden Barrel cactus
- Rusellia equisitiformis (Coral Fountain)
- Ruellia sp.
- Some citrus (Myer’s Lemon should be fine)
- Cold sensitive species of Agave
- Many small species of succulents
- Mother-in-law’s tongue (Sansevaria sp.)
- Young (less than 1-2″ trunk diameter) cold sensitive trees such as:
- Skyflower (Duranta erecta)
- Acacia sp.
- Texas Olive (Cordia boissieri)
Generally speaking, the central and east parts of the valley stay a little warmer, while the north, west and south perimeters get colder. Also, plants protected by enclosure in a courtyard or up next to a building receive some protection from cold winds.
Joshua Tree (Yucca brevifolia)
This is one of the reasons I love gardening so…along with the challenges come such unexpected and beautiful rewards. I planted these Bearded Iris about a year ago, forgot about them and either forgot or never knew what color flower to expect. Then along comes spring…kinda like Mother Nature on strong coffee, gettin’ stuff DONE!…and I glance over to see this amazing blue flower gracing my garden.
Iris are fun plants. There are over 200 named varieties, and the word “Iris” comes from Greek, meaning “rainbow”. They don’t seem to take much care, and bigger or more beautiful flowers are hard to find. Rhizomes (the “bulb” part of the plant) should be planted with the roots down and the tip up, just below soil surface or barely poking above. Avoid air pockets when planting, by placing a small mound of soil in the little planting hole you’ve created and spreading the roots over the pile. If you plant more than one (Iris looks great in groups of 3 or more), orient the fans (leaf-groupings) away from each other. In clayey soil plant them a bit high, create a little hill of sandy soil mixed with a little of your clay, or both…they like good drainage. Well-decomposed organic matter mixed into the soil will be helpful as well. Plant new rhizomes or divide existing ones in fall (September-November). They like full sun in most climates, but seem to do better here with intermittent, filtered or afternoon shade. Keep them fairly moist, but if soils stay wet they’ll rot.
Like all of gardening, expect some success and some failure. Of the 5 groupings of Iris I’ve planted, two have taken off and flowered, one produces leaves but hasn’t yet given me flowers, and two have died off. One of the ones that died was a variety named “Immortal”. Such irony! 🙂
I’m blessed to live near Frenchman’s Mountain (aka Sunrise Mtn) and often hike the canyons and slopes with my 3 dogs. It’s a rough, rocky, nearly soil-less mountain, but I’m continuously amazed by the desert life that thrives in such a seemingly inhospitable place. These two little cacti, Mammalaria tetrancistra, are about the size of golf balls. I bent to pet my dog and when I did they sure caught my eye. Talk about eye-popping! 🙂
They are commonly referred to as fishhook cactus, or corkseed cactus.
According to cactigiud.com, the genus Mammillaria is one of the largest of the cactus family, with nearly 200 recognized species.