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

 

Strawberry propagation, Heritage Harvest Festival

 

 

GFM-September 2013-cover-300pxThe September issue of Growing for Market is out. For this issue I wrote about our efforts to find a sustainable method of growing strawberries. We now use landscape fabric with holes melted in it, and keep the plants for two years. We are rebuilding after some years when the weeds overcame our previous beds, which had organic mulch (newspaper and hay). Our plan is to have two patches, and till in the two-year old one after harvest (after removing the landscape fabric and drip tape of course!), and make one new patch each summer. We’re a bit late this summer, but the system has promise, and I am optimistic!

Our new strawberry bed, using landscape fabric.  Credit Wren Vile
Our new strawberry bed, using landscape fabric.
Credit Wren Vile

In the past we have tried buying dormant plants in the spring (disadvantage: needing to weed the plants the first year and getting no fruit until the following year); buying plugs in fall (disadvantage: expensive) and various methods of propagating our own plants (mixed results).

We have tried keeping the plants for four years (disadvantage: way too much weeding); keeping the plants for two years (better); and accidentally keeping the plants for one year only (disadvantage: expensive).

We have tried organic mulch (disadvantage: lots of weeding); black plastic (disadvantage: unsustainable use of fossil fuels, and disposal was a pain); and now – landscape fabric. You can read all about how we do that in GfM.

As for the various methods of propagation, our current favorite is to grow our own plug plants from runner tips, using a home-built mister/fogger system. Our traditional method of propagating was to prepare new beds in late summer, then dig up runners from the paths or beds of the established plants and move them directly to the new beds. Success with these “Fresh Dug” plants relies on two weeks of intensive watering after planting. We also tried a method that worked well for me in England – pegging runners (still attached to the mother plants) down into small pots of soil for a few weeks until they had rooted, then snipping them from their mother plants and setting out a new bed. This works in rainy climates, or with overhead irrigation, but it didn’t work for us once we switched to drip irrigation. What a lot of trial and error!

New strawberry plants popped into the holes in the landscape fabric. Credit Wren Vile
New strawberry plants popped into the holes in the landscape fabric.
Credit Wren Vile

In my article, I mentioned cutting “runner tips.”  These are small unrooted runners, that need potting up and keeping alive for 4-6 weeks to grow into plugs. Here are instructions for the 6-8 week method we use when we propagate our own plants:

  • July 1-7: Fill 50-cell plug flats with screened compost. Water to activate the soil
  • July 8-14: Harvest runner tips or young runners, using pruners. Clip with ½” of the runner attached, to act as an anchor for the young plant. Choose runner tips with
    • 2 or 3 open leaves 2½-4” long (not more, not fewer, the researchers say).
    •  “Pegs” or nubs of developing roots, or roots up to ½” in length.
    • Large diameter crowns – pencil thickness if possible. Large = more flowers next year.
    • First or second position on the runner, not more distant from the mother.
    • Clip off any secondary runners coming from the daughter plants.
    • Sort the tips by size, planting that same day in 50 cell plug flats with like-sized tips, for best results.
    • Put the flats in a coldframe, water well, cover with thin white poly sheet (bin liner type), lightly perforated. Add shadecloth. Keep moist by watering daily as needed.
  • July 15-21: Continue daily watering. Remove shadecloth. Count live plants, harvest and pot more as needed.
  • July 22-28: Continue daily watering. Remove plastic, replace with rowcover. Harvest and pot more as needed.
  • July 29-Aug 4: Continue daily watering. Remove rowcover. Harvest and pot more if needed.
  • Aug 5-11: Continue daily watering. Harvest and pot more if needed. Remove shadecloth, plastic, rowcover from later harvested plants when appropriate.
  • Aug 12-Sept 1: Plant two staggered rows with plants 12” apart in all directions. Choose the biggest healthiest plants – it makes a lot of difference to the yield!

I reckon in our climate mid-September is about the last date for planting out new strawberries. If we miss that date, we should probably wait till February and lose a year’s production. Sad thought.

I want to explain how the 1/2″ of runner acts as a peg to hole the runner tip in the soil. No-one explained this to me when I first tried it, and at first it made no sense. Push the anchor at about a 45 degree angle into the soil in the plug flat. When the anchor is all in the soil,  press down with your thumb on the side of the crown of the plant opposite the anchor and turn the plant to stand it up. When you get it right it’s a wonderful thing – quick and elegant.

And I should say that propagating from unpatented varieties is fine, but propagating from patented varieties, even for your own use, is annoying illegal.

home-hhf-2013Meanwhile, I’m preparing my presentations for the Heritage Harvest Festival. If you are anywhere in central Virginia, consider going to this lovely event at Monticello, near Charlottesville. The weather forecast is very pleasant, the setting is delightful. Saturday 9/7 is the day. Click the link to read about the schedules, the vendors and the fun events. On Friday at 9am I’m doing a presentation on Asian Greens (there’s still some $10 tickets available for that one) and on Saturday at 10.30 I’m doing Succession Planting. That one is sold out. I’ll also be doing book signings at the Monticello Store after each of my workshops.

After the weekend, I’ll post my slideshows on SlideShare.net, and probably embed one in my next blog post, for those who miss the live show, and those that want to watch it again.