Q. When should we cover Pygmy Palm, Bougainvillea and other plants that will freeze here in Henderson? I have burlap to cover them.
|Bougainvillea freeze damage|
It seldom freezes in the Las Vegas Valley before Thanksgiving. After Thanksgiving you might expect freezing temperatures at the higher elevations such as in Summerlin or in very low spots in the Valley where cold air collects. In Henderson, this might be in the old Pittman area or along the wash.
Cold air, being heavier than warm air, settles into low geographic areas. Cold air tends not to settle on gently sloping land or hills.
Freezing temperatures are more frequent where plants are exposed to wind. Plants growing along major streets tend to freeze more often than those in protected backyards. Major streets are urban canyons that channel cold wind in the winter. Backyards are more nestled away from these exposed urban canyons.
|Sehgal palm cold damage|
Bottom line, when the weather forecast is for freezing temperatures, cover the plants with an old sheet, blanket, or in your case burlap, before nightfall. Drape this covering over the soil or any surface that can radiate heat at night. Remove this covering the next morning after temperatures are above freezing.
In open areas, expect freezing temperatures after Thanksgiving and up to March 1. In protected areas, expect these temperatures anytime between mid-December and mid-February but watch your local weather forecast closely and adapt this recommendation accordingly.