Frost isn’t the first thing that comes to mind when you hear words like Scottsdale, the Sonora desert or swimming in sunlight, but the fact is that every year we have a few frost nights in Scottsdale. The last two days, the early dawn hours have served us temperatures in the high 20s F ( -3° to -2° C) and the next couple of mornings will stay the same.
One indication of frost nights is that the cacti put their hats on. For the longest time I couldn’t figure out why people put upside down polystyrene cups on their cacti. At first I thought it was to protect the blossoms from birds but after driving past the big nursery on Scottsdale Rd who has “thousands” of cacti, all dressed with polystyrene hats, I did a u-turn and popped in to ask what was going on. The answer was that the cups help protect the sensitive tips/tops of the cacti.
I haven’t dressed our own cacti with hats but we have started wrapping our two potted lemon trees in burlap to give them a little extra protection during those cold morning.