Colorado potato beetles, germinating lettuce, wheelhoes

A ladybug on a potato leaf, looking for pests to eat Photo Kathryn Simmons

Not a Colorado potato beetle: A ladybug on a potato leaf, looking for pests to eat
Photo Kathryn Simmons

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

Some weeks I wonder what to blog about. This week I was helped by a neighboring grower who asked me questions about how I germinate lettuce. Aha! A timely topic! We try to grow lettuce for harvest all year round, here in central Virginia, and exactly how we do that varies with the season.
New flats of lettuce seedlings Credit Kathryn Simmons

New flats of lettuce seedlings
Credit Kathryn Simmons

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 mid-March to the end of April I sow in flats in the greenhouse, without extra heat.
Spring lettuce bed. Photo Wren Vile

Spring lettuce bed.
Photo Wren Vile

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.

From June I put shade-cloth over the lettuce seedbed, and only sow in the evening.
In July and August I put ice on top of the newly sown rows, under the shade-cloth.
baby lettuce mix in the hoophouse. Photo Twin Oaks COmmunity

Baby lettuce mix in the hoophouse.
Photo Twin Oaks Community

After that I sow lettuce mix in the hoophouse. (Click the link to see my Hoophouse in Fall and Winter slideshow.)

New Seed-Starters Handbook

Knotts handbook

Knotts handbook

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.

A soil thermometer soon pays for itself and saves lost crops and frustration. If it’s too hot, find a cooler place (put a seeded flat in a plastic bag in the fridge or on the concrete floor in the basement). Or cool down a small part of the world. That’s what I do when I sow in the evening, water with freshly drawn cold water, line up ice cubes along the seed rows, and cover with shade cloth.

And finally, to a tool we use a lot at this time of year (when the weather is dry enough for hoeing to be successful): our Valley Oak Wheel Hoes. We have two, both with pneumatic tires (rocky soil jars your wrists, think long-term). We have one with the standard 8″ blade and one with a 10″ blade. We use them for the aisles in our raised beds, for between rows of corn, anywhere without mulch. They are very energy efficient, compared to a hand hoe. And some of the crew treat he opportunity to wheel hoe as a chance for an aerobic workout. Others use a more moderate speed.Cover more ground with less effort, and hence, get more done before the weeds get too big to hoe.
The handlebar height is readily adjustable, the blade assemblies can easily be switched from one tool to another (buy one wheelhoe and several different width blades), there are other attachments such as  a small furrower, a one-sided hiller and a 3-tine cultivator. And there are plenty of replacement parts available: we just ordered spare blades after wearing ours down to narrow strips.9_zoom_1413981475