Solarization and crop choices to fight nematodes

Solarizing to combat nematodes. Photo Pam Dawling

Solarization

Solarization is a method of killing pests, diseases and weed seeds near the surface of the soil by covering the soil with clear plastic for six weeks or more in hot weather. We use this method to help control nematodes in our hoophouse. Nematodes are only active in warm weather, and we have not had problems with them outdoors, but of course, it’s warmer in the hoophouse!

I’ve written before about solarization to fight nematodes in our hoophouse.

In my Book Review: The Organic No-Till Farming Revolution: High Production Methods for Small-Scale Farmers, Andrew Mefferd, I wrote a little about solarizing:

“Solarization uses clear plastic (old hoophouse plastic is ideal). In a summer hoophouse, solarization can be as quick as 24 hours, Andrew says. When we’ve done this, one of our goals was to kill nematodes and fungal diseases, not just weeds, so we waited a few weeks. Outdoors it takes several weeks. You can see when the weeds are dead. Bryan O’Hara poked a thermometer probe through solarization plastic and found a 50F degree (28C) difference between the outside air and the soil immediately under the plastic; a 10F (6C) difference at 1″ (2.5 cm) deep and little temperature gain lower than that. Solarization does not kill all the soil life!”

Extension offers Solarization and Tarping for Weed Management on Organic Vegetable Farms in the Northeast USA which can, of course, be modified for those of us in other regions.

Solarizing to combat nematodes: Step on a spade to push the plastic down into a slot in the soil.
Photo Pam Dawling

Nematodes

I’ve written here before about our struggles with root knot nematodes in our hoophouse, and you can read everything I know about nematodes in the Year-Round Hoophouse.

My article on nematodes in Growing for Market  in November 2014 describes our discovery of the beasties and our first attempts to deal with them.

My most thorough blogpost about nematodes was for Mother Earth News  Managing Nematodes in the Hoophouse.

Cucumber roots with nematodes (see circles).
Photo Pam Dawling

My post Good news – great hoeing weather! Bad news – more nematodes in the hoophouse August 2014 includes a photo of our first attempt at solarizing – a  bit of a How Not To!

There is info on dealing with nematodes from Garry Ross in Hawaii, where nematodes are a fact of daily life, in my post Cold weather, snow, thinking about nematodes from February 2015.

Cover Crop Choices

French marigolds and sesame to deter Root Knot nematodes in our hoophouse.
Photo Pam Dawling

In June this year I wrote about using marigolds, sesame, Iron and Clay cowpeas as nematode resistant cover crops. We’ve also used winter wheat, and white lupins. See Our Organic Integrated Pest Management . Other cover crops that suppress nematodes include some other OP French marigold varieties (but avoid Tangerine Gem or hybrid marigolds); chrysanthemum; black-eyed Susan; gaillardia (blanket flower, Indian blanket); oats; sesame/millet mix. We decided against sorghum-sudangrass (too big), winter rye (harder than wheat to incorporate by hand), bahiagrass, Bermuda grass (both invasive), castor bean and Crotolaria (sunnhemp) (both poisonous, although newer varieties of Crotolaria have lower toxin levels, and I’ve been rethinking my opposition to using that), partridge pea, California poppy (both require at least one full year of growth) and some obscure vetches that weren’t available locally. We might have included Pacific Gold mustard (B. juncea), if we’d found it in time. Don’t confuse this with Ida Gold Mustard, which kills weeds, and is susceptible to nematodes.

Food Crop Choices

 This list starts with the crops most resistant to Root Know Nematodes and ends with the most susceptible. I’ve included some “bookmarks” between categories, but it can also be read as a continuous list:

Scallions in our hoophouse in late November.
Photo Pam Dawling

Most resistant

Strawberries

Rhubarb

Onion (? not certain)

Corn

West Indian Gherkins

Horseradish

Asparagus

Jerusalem Artichokes

Globe Artichokes

Radishes in our hoophouse in February.
Photo Pam Dawling

Fairly Resistant

Ground Cherry

Some Sweet Potato varieties

Radishes (? not certain)

Rutabagas

Garlic, Leeks, Chives

Cress

Brassica juncea mustards

Brassica rapa var. japonica greens (? Uncertain)

Broccoli, Kale, Collards, Brussels Sprouts

Red Russian kale from Southern Exposure Seed Exchange in our hoophouse in March.
Photo Pam Dawling

Somewhat Susceptible:

Fall Turnips

Peas

Fall Spinach

Swiss Chard

Parsnips

New Zealand Spinach

Very Susceptible:

Lettuce

Cabbage

Cucumbers, Muskmelons, Watermelons, Squash, Pumpkins

Beans, Fava Beans, Soybeans

Okra

Beets

Carrots, Celery

Tomatoes, Eggplant, Peppers, Potatoes, Peanuts

Ruby Streaks, Golden Frills, Scarlet Frills juncea mustards, very resistant to root-knit nematodes.
Photo Pam Dawling

Nematode-resistant winter greens

 We came up with a collection of nematode-resistant winter greens, including radishes, Russian kales, Brassica juncea mustards (mostly salad greens like Ruby Streaks, Golden Frills, Scarlet Frills), and Brassica rapa var. japonica greens, mizuna and Yukina Savoy. We have since learned that Yukina Savoy is a Brassica rapa, not B. juncea as we thought, and that mizuna is Brassica rapa var. japonica with a less certain resistance, or perhaps Brassica rapa var. niposinica, or perhaps B.juncea after all (integrifolia type). We also grow scallions in the nematode-infested areas. Now I am looking for more nematode-resistant cold-weather greens.

Green mizuna in our hoophouse in November.
Photo Pam Dawling

This Year

After the winter greens this spring, we transplanted two beds of tomatoes, one each of peppers, squash and cucumbers, and put two beds into Iron and Clay cowpeas. The eastern ends where we had found evidence of nematodes, we transplanted French marigolds and sesame as stronger fighting forces.

When we pulled up the squash and cucumbers  we found no sign of nematodes on the roots. One of the tomato beds produced no sign either, but the other one did. Our first response was to sow Iron and Clay cowpeas instead of the planned soybeans, but before the plants were even 2” (5 cm) high, we decided to solarize that whole bed. We now have small patches of nematode infestation in almost every bed, calling for a more nimble approach to crop planning.

Brassica juncea mustards to try

According to Wikipedia, Brassica juncea cultivars can be divided into four major subgroups: integrifolia, juncea, napiformis, and tsatsai.  I did some searching for more B. juncea, especially large leafed ones. Some promising looking crops include these:

“Green-in-Snow” mustard, Serifon gai choi type Chinese Mustard, Suehlihung.

Serifon (Suehlihung, Green-in-Snow) mustard. Kitazawa Seeds

“Red-in-Snow” mustard (sorry, no details)

Osaka Purple Mustard. Fedco Seeds

Giant Red, Osaka Purple, Southern Giant Curled Mustards, all quite pungent

 

 

 

 

 

 

Horned Mustard. Wild Garden Seeds

Horned Mustard

 

 

 

Miike Giant mustard. Kitazawa Seeds

Miike Giant

 

 

 

 

Hatakena Mustard. Kitazawa Seeds

 

Hatakena

Yanagawa Takana.
Kitazawa Seeds

 

 

 

 

 

Yanagawa Takana broad leaved mustard

 

 

 

Wasabina baby leaf mustard (wasabi flavor). Kitazawa Seeds

 

Wasabina

Rainy day garden reading (listening and viewing)

New Format Website

After all this time, my website was due for some spring cleaning. In particular, the old format didn’t work well on smart phones, and this new one does. So I hope that makes life easier for lots of you! I’ve also moved the Categories and Recent Comments so they are easier to find. Let me know  if you have ideas for improvements.

Our Weather

It’s cold and rainy here as I write this (almost sleeting). I will need to plug in the heat mats under the pepper, eggplant, cucumber and squash seedlings, cover the tender potted tomatoes and peppers in the greenhouse with rowcover, and pull rowcover over the newly transplanted beds of tomatoes and squash in the hoophouse. I’m expecting a third night with temperatures around 25F (-4C). Hence I’m in the mode of staying indoors and doing some reading. Here’s a big round up of good stuff.

Root Crops and Storage Crops

In A Way to Garden Margaret Roach interviews Daniel Yoder of Johnny’s Seeds on Mastering Root Vegetables. Read, or listen to her podcast how to grow root crops: Carrots, beets, radishes, parsnips. Lots of tips, and links to more articles/interviews

An earlier article discusses how to store garden vegetables for winter. Margaret covers the basics of temperature and humidity, along with details of some crops and ideas for preserving crops that don’t store well.

Ticks and Tasks in Virginia

The Garden Shed is a monthly online newsletter published by the Piedmont Master Gardeners.  It provides all gardeners in Charlottesville-Albemarle County area of Virginia with a science-based, reliable source of gardening information, monthly tasks and tips, and other gardening related features. Here are a couple of the most recent ones:

Managing the Tick Problem by Ralph Morini

Identifying the culprits, understanding the medical risks and tickproofing your environment

March Tasks in the Vegetable Garden by Ralph Morini

Of Wet Soil, Pests and Hope…

Note that the link in this article to VCE Publication 246-480 “Vegetables Recommended for Virginia,” does not work. It looks like the Extension has taken the publication down. Ralph Morini suggests that the next best reference is 426-331 Vegetable Planting Guide and Recommended Planting Dates

Diversify and Profit

10 Most Profitable Specialty Crops to Grow

This post by Craig Wallin for the Profitable Plants Digest gives info on lavender, gourmet mushrooms, woody ornamentals, landscaping trees and shrubs, bonsai plants, Japanese maples, willows, garlic, bamboo and herbs. I’ll add a big caution about bamboo, as we have found many bamboo varieties very invasive and hard to control. Links on the site provide info on ginseng, microgreens and more.

Siberian garlic.
Photo by Southern Exposure Seed Exchange

Pick High Yield Crops

Practical Farmers of Iowa offers an interactive list of Farmer to Farmer Vegetable Yield and Production Data

Get an idea of what a reasonable yield is (at least in Iowa!) of the crops you grow and compare various crops to help with your decision-making.

Control Weeds the Easy Way

Extension offers Solarization and Tarping for Weed Management on Organic Vegetable Farms in the Northeast USA which can, of course, be modified for those of us in other regions.

Reusable Black Tarps Suppress Weeds and Make Organic Reduced Tillage More Viable

A black plastic tarp laid over full-length crop beds. Photo credit: Haley Rylander.

Remediate Contaminated Soil

 


Most public universities – and many private companies – offer mail-in soil testing for a nominal cost. Photography By Humannet / shutterstock.com

Urban Gardening 101: How to Deal with Contaminated Soil It’s hard to find much information on this topic for organic gardeners, although Leah Penniman does also offer help in her book Farming While Black

 

Listen to Podcasts

Modern Farmer Ten Great Farming Podcasts to Listen to Now

 

Watch a Movie on Heirloom Seed Preservation

Al Jazeera, in their Witness series, has a 25 minute film The Seed Queen of Palestine
Can one woman’s mission to revive ancient heirloom seeds inspire a celebration of traditional Palestinian food? Vivien Sansour is distributing rare, ancient heirloom seeds to Palestinian farmers. Click here and search for The Seed Queen of Palestine

Track the Progress of Spring

The Nature’s Notebook phenology site

Join more than 6,000 other naturalists across the nation in taking the pulse of our planet. You’ll use scientifically-vetted observation guidelines, developed for over 900 species, to ensure data are useful to researchers and decision-makers. On their website, learn about the National Phenology Network Pest Patrol which is seeking observers to report their sightings of insect pest species that cause harm to forest and agricultural trees. Your observations as part of this campaign will help validate and improve the USA-NPN’s Pheno Forecasts, which help managers know when these species are active and susceptible to treatment.

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Heed the Warnings for Agriculture from the Fourth National Climate Assessment

The U.S. Global Change Research Program has released the Fourth National Climate Assessment, an examination of the effects of climate change on the United States. Chapter 10 of the Assessment is on “Agriculture and Rural Communities.” This chapter contains four key messages regarding productivity decline, resource degradation, livestock health, and rural-community capacity to respond.

Consider Water-saving Hoophouse Crops.

Texas High Tunnel Workshop

Texas high tunnel study expands

The Texas High Plains and Southern Plains continue to experience reductions in irrigation water from the Ogallala Aquifer as water levels decline, and producers need some way to improve their revenue from their farming systems. They have the potential to get a pretty good return and be able to take better advantage of the water they do have, using high tunnels to grow regular vegetable crops and also use them for seed production, cut flowers, small fruit.

Consider our own Impact

Here are 6 personal Carbon Footprint Calculators

from Mother Earth News

Be Amazed

Bug Tracks blog
Bug Tracks logo

Bug Tracks Charley Eiseman Life in a Cubic Foot of My Lawn. This inspiring article is one of many by this expert in leaf miners as well as other insects. It’s such fascinating stuff! And his photos are exquisite. There are over 40 in this post!

Learn about Vegetable Grafting

Members of a Specialty Crops Research Initiative Grafting Project Team have organized a grafting webinar series. The webinars each cover a different topic about the science and technology of vegetable grafting. While not specifically about organic production, upcoming topics that could be of interest to organic growers include Grafting to Increase Production for Small-acreage and High Tunnel Tomato Growers, by Cary Rivard of K-State University; past topics include Making Grafting Affordable and Beneficial to US Growers by Richard Hassell of Clemson University. Past presentations in the series were recorded and archived. Find the recordings on the project YouTube channel here, and learn more about upcoming webinars here.

See Enhancing the Utility of Grafting in US Vegetable Production, by Matthew Kleinhenz of the Ohio State University, below.

If you are a gardener, you may be interested in another webinar by Cary Rivard about grafting for home gardeners: Demystifying Grafted Tomatoes: The Why & How for Gardeners, which is part of the 2019 series of Advanced Training Webinars for Master Gardeners sponsored by Oregon State University Extension. Find out more information here.

Read up on New Research

eOrganic recorded presentations on current organic research from the Organic Research Forum organized by the Organic Farming Research Foundation at Organicology. The following presentations are freely available now and more will be added to their playlist on the eOrganic YouTube channel and mentioned in upcoming newsletters. Find the program here and click here to find the recordings on a YouTube playlist.

Help Beginning Farmers in Virginia

In partnership with First Baptist Church, Tricycle Gardens in Richmond, Virginia, are developing Charlotte Acres Incubator Farm with graduates of the Urban Agriculture Fellowship & Certification program launching their businesses and farming this beautiful land. They ask for donations: Please consider a generous gift today in support of beginning farmers. 

Diversified Vegetable Apprenticeship Manager Dan Dalton meets with Apprentice Jess Hermanofski at host farm Plowshare Produce, an organic CSA farm in Huntingdon County, PA

Become a Farmer Apprentice in Pennsylvania

Pennsylvania Registers Its First Formal Apprenticeship for Farmers

The Pennsylvania Department of Labor and Industry approved the Diversified Vegetable Apprenticeship on March 14th, making it the first formal apprenticeship program for farmers in the state.

Enjoy a Garden Walk in Virginia during Historic Garden Week April 27 – May 4, 2019

Springtime begins with Historic Garden Week At Monticello, Charlottesville, Va

In addition to Monticello’s regular guided Gardens and Grounds Tours, the annual observance of Historic Garden Week in Virginia will include talks, behind-the-scenes tours, and an open house at our Thomas Jefferson Center for Historic Plants.

Insider’s Tour with the Vegetable Gardener: Discover great gardening ideas from Jefferson’s kitchen garden during this Q&A walk with Monticello vegetable gardener Pat Brodowski. Tuesday, April 30, 10-11:30am