December 1972 began as an unexceptional month, although somewhat rainier than usual. At the end of the first week a light snow fell—unusual but not rare.
The snow melted quickly as it usually does in Berkeley. But instead of returning to the normal weather pattern for the month, the cold deepened.
Memory has a way of making droughts deeper, rains more torrential, and heat more intense. But this iron-fisted cold, which has persisted in the memory of those who were here, was truly cold. Nights around the Bay Area were well below freezing, averaging 23-28 degrees F. During the day, the thermometer struggled to reach 40 degrees F. Worse, the cold continued for a week.
In Strawberry Canyon, it was even colder. For two nights in a row the temperature plunged to 14 degrees F and stayed below freezing even during the day. At the UC Botanical Garden, 1500 plant species were killed. The African collection, especially the areas known as African Hill and the New World Desert which share the same slope, were the hardest hit. The cold even reached into downtown Berkeley where all the ficus, planted as street trees on Telegraph Avenue, were frozen.
The neighbors north of Lawrence Hall of Science watched helpless as their gardens died. Vines released their grip and turned brown. Succulents drooped and as their cells burst, dissolved into a black mush. Important landscape hedges were frozen. Only the hardiest plants like the conifers survived. One gardener, hoping to save his garden, ran his sprinklers—turning his garden into a complex ice sculpture—until the water froze in the hoses. Many people had no water at all when their pipes froze and broke. Ice-covered driveways trapped cars in their garages.
Anna’s Hummingbirds, our one year-round hummer, deprived of the flower nectar to fuel their constant need for food, were found comatose. People put out hummingbird feeders, but the sugar water had to be frequently thawed.
And what became known as the Big Freeze of 1972 transformed the hillside landscape, when two to three million blue gum and river red gum eucalyptus froze to the ground. Though many of the trees survived and later sprouted from their stumps, the dead growth above ground had to be cut and removed ahead of the summer and fall fire season. Local emergency rooms treated an unusual number of broken bones as homeowners tried to cut down their own trees. Lawrence Hall of Science and the Space Sciences building lost their green surround.
After that punishing December, the Botanical Garden planted fewer frost-sensitive plants. But after a few years, hillside gardeners with shorter memories once again planted trumpet vines, bougainvillea, and citrus. This December, when the thermometer dropped briefly below freezing on two mornings, only the most tender plants were nipped.
--Phila Rogers
Phila Rogers
Phila Rogers is a Lawrence Hall of Science neighbor who has lived on the hill for 58 years. Until retiring, she was a science writer at Lawrence Berkeley National Laboratory where she also wrote “Nature Note” for the weekly publication. As a volunteer with the UC Botanical Garden she co-leads quarterly bird walks. She is also one of the founding members of Save Strawberry Canyon.