Newcomers to Sedona who plant Bougainvillea or Lantana in the fall go through a learning experience and then realize why they don’t see them planted all over town like in their former towns. The reason is freezing temperatures. Subtropical plants cannot withstand temperatures much lower than 32 degrees. But plant materials are not the only concern when it comes to cold weather. Irrigation systems, masonry and fountains are also concerns for Sedona landscaping in winter. Here I share some winter weather lessons learned for your Sedona landscape.

Plantings

Sedona has a USDA cold hardiness zone of 7 or 7b, which means the average lows can reach 5 to 10 degrees Fahrenheit. Some subtropical plants can tolerate an infrequent dip below freezing, but a series of cold nights below 25 or so can be deadly, especially if the root system is not established as in newly planted. The best thing to do to deal with our cold winters is to choose plants that can tolerate Zone 7 and treat others in higher zones as annuals, or expect them to lose their leaves during winter.

Lantana is a colorful plant that is widely planted in the Phoenix area which is Zone 11, but I have seen some Lantana around Sedona as well. The difference is they lose their leaves after the first frost even though they are considered an evergreen shrub. They should be cut back in late winter to trigger new growth in the spring.

Plants that can tolerate our winters are ideally planted in the fall when the soil temperature is still warm enough to allow for some root growth before winter. Planting during winter is okay for some plants in containers, but don’t expect any growth till spring. It’s better to wait and not risk losing these newly planted shrubs especially if they are small 1 gallon containers or came directly out of the greenhouse at the nursery.

 Arizona Municipal Water Users Association How to Prune Frost Damaged Plants

Irrigation/pipes

People who come from harsh winter climates know how to winterize their homes. Exposed pipes can burst when frozen water expands, even a copper pipe can burst. That is why all exposed piping above ground should be insulated. Pressure Vacuum Breakers (or PVBs),  are those devices near your water meter and keep water from back flowing into the municipal water system. PVBs have an internal plastic part that can freeze and break, causing a major leak to occur under pressure. They must be above ground to function, and thus vulnerable to the elements.

 

Protect them with specially made thermal insulated pouches.

 

 

 

 

PVC piping that feeds your valves or sprinkler system is also at risk if it is holding water during a freeze. It’s best to have a bleed valve at the lowest part of the system to drain all the water from the pipes. If your site is level, you can dig a dry well to create a low spot for the water to drain. Also shut off the water supply that feeds the irrigation system, so in case a leak does occur, the system will not be under pressure creating a significant waste of water until you discover it in the morning.

Hardscape

Our climate is not cold enough to be concerned with soil freeze thaw conditions as in the Northeast. Hardscape such as concrete, masonry stone and tile is more susceptible to water penetrating their surfaces, freezing and then expanding and causing cracks or lifting of the top surface.

Care must be taken with certain installations during winter so water is not trapped underneath freshly laid tiles or stone. If gaps and crevices are present, these are areas where water can accumulate. A tile job for example should be laid, grouted and sealed without water infiltration and without freezing.

Drainage is also very important so that the surface does not collect water or snow.

 

 

Fountains

It is recommended that pumps be operating during freezing conditions, otherwise water inside the pump may freeze and damage the pump. Flowing water also helps keeps the water from freezing in the plumbing. Sometimes, however it is best to shut down the fountain for the winter depending on the kind of fountain or water feature you have.

A fountain with relatively shallow basins such as a shallow bowl like a bird bath will freeze solid if cold enough at night. If the material is prone to crack due to the expansion of the ice, the vessel itself may be at risk, so it would be better to drain the water from the vessels and turn off the pump.

Since there are so many different kinds of fountains, it is best to ask, what if the pump stopped running and all the water in the basin and the bowls froze solid. Could the fountain otherwise remain intact without cracking? Is the material reinforced? Or is it made of fiberglass or resin? How easy would it be to remove the pump and bring it indoors? These questions should be asked when designing and installing a fountain whether its custom built or prefabricated.

 

This urn style fountain to the left if filled with water and froze, may expand and crack the vessel because of its shape. However, these wok style bowls to the right, have a very large surface area of water that if expansion occurs would simply rise in the bowl.

 

 

 

Conclusion

When spring comes and the weather warms up, its easy to forget about frozen pipes and plants that died during the first freeze in November. The best strategy for Sedona landscaping is to plan around the worst season of the year — winter and its freezing temperatures rather than the heat of the summer.

 

 

Tagged with:

Filed under: Sedona Landscaping

Like this post? Subscribe to my RSS feed and get loads more!