Our spring-planted potatoes are just starting to flower, and I’m now in my weekly routine of monitoring for Colorado potato beetles. I walk the length of the patch and back, switching rows every 9 paces or so. I squish and count the adult CPB, and also count the larvae (I don’t always squish all of those). Did you know you can tell a squashed female CPB from a squashed male? The females are full of orange eggs, until you squash them, that is, then the orange eggs are all over your fingers!
Potato plants can tolerate 30-40% defoliation early in life, 10-60% defoliation during middle age, and up to 100% defoliation at the end of the season without reducing the yield.So don’t panic! But do pay attention. The Action Level for Colorado potato beetle is 1 adult per plant, and that for larvae is 2 per plant. Our rows are 265 ft this year, and the plants are 12″ apart, so I’m looking at 530 plants when I go down and back. So far, we’re doing great. Last week I found 12 adults. This week I found 5 adults and 41 larvae. I still don’t need a mass slaughter program. If we need to spray I’ll use Spinosad. For home gardens you can buy Monterey Garden Insect Spray from Seven Springs Farm in Virginia. Or elsewhere. It is OMRI approved but is very toxic to bees (and Eastern Oysters, should you need to know), so we only spray Spinosad at dusk when the bees have gone home, and make sure not to pour the rinse water from the sprayer into the drains (which go via our septic system into the creek). Generally I use the driveway as a large inert area to spread the wash water over.
But I only use Spinosad if we have to. Another part of my plan is timely mowing of the clover patch next to the potatoes. The clover mix was undersown in the fall broccoli last year, and in the spring we simply bush hog that patch every time the weeds are getting too successful compared to the clover. Or ideally, before that happens. We had flowering crimson clover there earlier, and mowed that. Now what we see is white clover. there is red in the mix too, but I haven’t seen that flowering yet. Our hope/plan is that when we mow the clovers, many of the beneficial insects move over to the potato patch and eat the CPB.
At the great link I gave earlier, Andrei Alyokhin provides good information on the life cycle of the CPB, lots of resources, and a lovely collection of Colorado potato beetle haiku (traditional Japanese poetry) written and illustrated by Mrs. O’Malley’s second-grade students from the Old Town Elementary School in 2008 or so, somewhere in Maine I think. The poetry gives new perspectives as we walk the rows searching for the wee beasties.
Germinating lettuce seed
From January until mid-March I sow in flats in the greenhouse, with heating to get the seeds germinated, then good old solar energy to grow them to transplanting size.
From May to late September I use an outdoor nursery seedbed and do bare-root transplants (heat-tolerant varieties). The soil temperature does not vary as much as the air temperature, so I don’t worry about cool nights.
After that I sow lettuce mix in the hoophouse. (Click the link to see my Hoophouse in Fall and Winter slideshow.)
There’s a chart of germination at various temperatures in Nancy Bubel’s New Seed Starter’s Handbook and in the Knott’s Handbook for Vegetable Growers which is all online.The soil temperature range for germination of lettuce seeds is 35-85F, with 40-80F being the optimum range and 75F the ideal soil temperature. At 41F (5C) lettuce takes 15 days to germinate; at 50F (10C) it takes 7 days; at 59F (15C) it takes 4 days; at 68F (20C) only about 2.5 days; at 77F (25C) 2.2 days. Then time to germination increases: 2.6 days at 86F (30C); after that it’s too hot.