Cool May, hot June: Taking stock of weird weather
During the last two weeks of May, we were more than 13 degrees below our average high for the date. One day barely reached 58 degrees, when our average was 82! Nighttime lows were significantly below average, and well below the temperatures preferred by the subtropical plants that make up our summer vegetable and flower gardens. Soil temperatures mid-month began dropping, reaching levels more typical for early April. At one point, soil temperature was dropping one degree each day. We had nearly 3 inches of rain (2.88) when we normally get about half an inch.
Of particular note for disease concerns, we had a four-day period of intermittent rainfall with little break in the cloud cover. Moisture conditions on leaf surfaces were very favorable for inoculation and spread of fungus and bacterial diseases.
“Is all this wacky weather having an effect on the garden?”
You bet. Ag took a hit on some crops as well. “STOCKTON — California’s cherry crop has been significantly damaged by rain, shortening supplies for upcoming Memorial Day sales. The crop was originally estimated at 10 million, 18-pound boxes with many in the industry expecting it could reach 12 million boxes. ‘I’m still optimistic we will come out with 6 to 7 million after the rain finishes,’ said Don Walters, domestic sales agent for Grower Direct Marketing in Stockton. … Most damage was to the early Tulare and Brooks varieties in all growing regions, Walters said. The Bing crop east of Stockton was still green enough to escape damage and should be a good crop the second week of June, he said.”
We are already seeing renewed cycles of disease infection on fruit trees. A couple of days before the first storm blew in, I heard spray rigs operating in most of the walnut orchards around where I live. The growers were trying to get a round of fungicide on before the soil got too saturated for tractor work. A quick walk in the orchard found fireblight, brown rot, even mildew on young shoots and fruits.
As my friend Farmer Fred of KFBK and KSTE fame put it on Twitter on May 18: “When it rains in spring … peach leaf curl, apple and pear scab, fireblight, fruit drop, late blight, rust, downy mildew, tomato fruit cracking, cherry cracking, black mold, bacterial speck, rots, phytophthora, more snails, wilts. Have a nice weekend, gardeners!” As the saying goes, today’s weather makes next week’s problems.
From my ongoing notes about trending disease and pest problems, here is the parade of samples the second half of May:
Cool Davis is a coalition of citizens, the City of Davis, and community organizations working to empower our community to reduce greenhouse gas emissions.