by Rainer Hoenicke

Back yard before reducing meadow 2018

Pathogen Mitigation Measures during the Pandemic

In anticipation of tomato season and my recently acquired knowledge of Fusarium and Verticillium wilt, I used the 2020 Coronavirus lock-down to think seriously about avoiding or at least mitigating my previous decade of tomato failure on my suburban lot. How ironic – while avoiding exposure to a new virus that is believed to have jumped the species barrier from bat to human, I am now also engaged in figuring out how to reduce exposure of my newly sprouted heirloom tomato seedlings and this spring's Master Gardener Tomato Sale specimens to a plant pathogen of a different sort – two soil-borne fungal species that are even more ubiquitous than the COVID-19 virus.

Cultural practices and selection of resistant tomato varieties seem to be the only means of mitigating these fungal diseases. Although my suburban lot is larger than most within the Napa city boundaries, it doesn't lend itself very well to rotational practices, since spots that receive more than six hours of sunlight each day are scarce, with all the big trees not only in my own yard but throughout the neighborhood. We are truly living in an urban forest with only a few clearings here and there.

 So, I had to think creatively and take the time to strategically plan how to install the equivalent of a “Victory Garden” without a partial or complete tomato and pepper harvest failure. Here are the questions I asked myself:

1)    Where do I get more than six hours of sun exposure in my yard?

2)    Of those areas in my front and back yards, which have not contained vegetables in the nightshade family for at least the last five years?

3)    What is growing there now, and is it worth re-purposing that area for growing tomatoes, peppers, potatoes, or eggplant?

After expanding veggie area 2020

Using cardboard for sheet mulching, topped generously with mulch acquired in February, while the yard waste composting facility was still open, has made removal of the Bermuda grass and other weeds in the backyard meadow relatively easy. The strips between rows of lavender, Ranunculus, Echinacea, and culinary sages are now looking forward to receiving a diverse mix of summer vegetables, and I am hoping for a tomato harvest beyond just a salad or two.

Informational links:

UC IPM-Fusarium https://vric.ucdavis.edu/pdf/diseases_fusariumwilt.pdf

Morton Arboretum-Verticillium 

https://www.mortonarb.org/trees-plants/tree-and-plant-advice/help-diseases/verticillium-wilt

Univ of Wisconsin-both https://cdn.shopify.com/s/files/1/0145/8808/4272/files/A2617.pdf

UC ANR-Tomatoes https://ucanr.edu/sites/ucmgnevada/files/183442.pdf https://anrcatalog.ucanr.edu/pdf/8159.pdf

Sheet mulching

UCMG Marin County http://marinmg.ucanr.edu/Manage_A_Garden/Composting/Sheet_Mulching/

UCMG Contra Costa Co http://ccmg.ucanr.edu/files/221117.pdf

During Napa County's shelter in place directive that protects everyone's health and safety, Napa Master Gardeners are available to answer garden questions by email: mastergardeners@countyofnapa.org. or phone at 707-253-4143.  Volunteers will get back to you after they research answers to your questions.

Visit our website: napamg.ucanr.edu to find answers to all of your horticultural questions.

Photo credits: Rainer Hoenicke

After expanding veggie area 2020

Editor's note: Master Gardeners are keeping busy in their own gardens during Napa County's “Shelter in Place” directive. It's spring, it's getting warmer, it's a great time to work in the garden! Here's how Master Gardeners are spending their time:

California Poppy-Eschscholzia California (Papaveraceae family)

By Linda McClimans

The Poppy, California's State Flower, is native from western Oregon to Baja California, but its range extends to southern Washington, Nevada, Arizona, New Mexico, and Sonora Mexico.  It was named for the surgeon/entomologist J.F. Eschscholtz who was on a Russian expedition that dropped anchor in San Francisco Bay in 1816.  It was designated state flower by the California State Floral Society in 1890 and made official in 1903.

According to the UC Davis Arboretum and Public Garden, the poppy is technically an annual but will “perennial-ize” by sprouting the following year from their roots and lower stems or by reseeding.

In Napa's Mediterranean climate, sow the seeds shallowly and directly in the ground in fall. Seeds will germinate after fall rains or when the soil warms up and will bloom in spring and early summer. Then the tops will die back, seeds will drop and the plants become dormant. When mature, seedpods snap audibly and scatter the seeds.  To save the seeds, pick off pods before they are completely mature and keep in a dry container.  Seeds readily germinate the next year. Unless there is very little rain, watering is not usually needed.  Even with very little rain this year in Napa County, poppies are profuse on untended hillsides. Growth is best in full sun. These poppies are obviously drought tolerant. 

Plants grow 2-24 inches tall with branching, divided, blue-green foliage.  Flowers are solitary on long stems with four distinctly large petals.   Flowers close at night and on overcast days.

Seed catalogs now offer many different colors (white, cream, yellow, apricot, orange, pink, rose, scarlet, and purple) and styles (frilly, ruffled, semi double and double).  They do not make good cut flowers as petals readily drop.

References:

California Poppies by Sue Rideout, UC Master Gardener 4/12/2012

https://ucanr.edu/datastoreFiles268-523

USDA/US Forest Service

https://www.fs.fed.us/wildflowers/plant-of-the-week/eschscholzia_california.shtml

The California Poppy by Michelle Le Strange, UC Master Gardener Advisor 5/10/2007

http://ucce.ucdavis.edu/files/datastore/268-304

UC Davis Arboretum-plants for bees

https://arboretum.ucdavis.edu/blog/support-california-native-bees-these-10-plants

During Napa County's shelter in place directive that protects everyone's health and safety, Napa Master Gardeners are available to answer garden questions by email: mastergardeners@countyofnapa.org. or phone at 707-253-4143.  Volunteers will get back to you after they research answers to your questions.

Visit our website: napamg.ucanr.edu to find answers to all of your horticultural questions.

Photo credits: This photograph was taken by Master Gardener Penny Proteau on 4/2/2020 at Moore Creek Park.

Editor's note: Master Gardeners are keeping busy in their own gardens during Napa County's “Shelter in Place” directive. It's spring, it's getting warmer, it's a great time to work in the garden! Here's how Master Gardeners are spending their time:

By Linda McClimans

Sweet Peas- Lathyrus odoratus

Sweet peas

Vine types can grow from 5-9 feet long and be grown over rocks, on the ground or can be trellised or grown on a fence.  Bush types grow 12-30 inches, do not need support and can be grown as a border, in beds or in pots. Plants do best in full sun (minimum of 6-8 hours), but best with up to 16 hours of daylight.  More light generally means more flowers.  Plant in well cultivated soil rich with composed manure and keep evenly moist during the growing season. Mulching is suggested.

Use clean fresh seeds which should be soaked overnight.  Any seed not swollen after soaking may be chipped (use a knife to chip or break through the skin on the seed.)  Start in an unheated greenhouse, cold frame or right in the ground.  Seeds usually emerge in about 10 days but it can take 2 weeks or more. Pinch out the growing tips when they are about 6-8 inches tall to stimulate lateral growth and bushiness.  This is an especially good time to mulch if you have not done so yet.  Fertilize with ½ strength liquid fertilizer twice during the growing season.  Too much fertilizer encourages an abundance of foliage at the expense of flowers.  Pick off spent flowers and seedpods to encourage new blossoms.

If you plan to grow sweet peas in the same spot next year, just allow the seedpods to dry and they will pop open and seeds will fall to the ground.  Next year's flowers will grow from these seeds. If you wish to plant seeds in another area or to share with other gardeners, stop deadheading plants and the pods will begin to form after the flower dies.  Begin saving seeds from pods after the shells turn brown and brittle. If harvested too early, seeds will not germinate. If you wait too long, the seedpods will break open and the seeds will fall to the ground.  The process can take a couple of weeks so check them often.  If the pods begin to split, pick them right away.  Remove the seeds from the pods and lay on a flat surface lined with newspaper.  Let the seeds dry for about three days.  Once dry, put seeds in a freezer bag or Mason jar with a tight fitting lid to keep them dry.  Store in a cool place until planting time. Pests include birds, slugs, snails, aphids and thrips.

I have found sweet peas easy to grow.  I planted the seeds directly into the ground without soaking them.  While they took a long time to germinate, they did.  I have not been especially careful with the watering and yet my plants have grown nicely.  I grew them in three separate beds and had a huge bird problem in only one of them.  Every time the plants grew to about 2 inches tall, the birds took them back to 1 inch.  Finally, I added mylar tape to the trellis (I used my tomato cages for trellising) and although the plants are way behind the others, they have finally started to bloom.

References:

UCIPM Sweet Peas- http://ipm.ucanr.edu/PMG/r280113211.html

Sunset Garden Book- 9^th edition, page 400

Under the Solano Sun: Sweet Pea-Flower of the Month 4/11/2012

https://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=7236

During Napa County's shelter in place directive that protects everyone's health and safety, Napa Master Gardeners are available to answer garden questions by email: mastergardeners@countyofnapa.org. or phone at 707-253-4143.  Volunteers will get back to you after they research answers to your questions.

Visit our website: napamg.ucanr.edu to find answers to all of your horticultural questions.

Photo credit: Linda McClimans

Editor's note: Master Gardeners are keeping busy in their own gardens during Napa County's “Shelter in Place” directive. It's spring, it's getting warmer, it's a great time to work in the garden! Here's how Master Gardeners are spending their time:

by Melody Kendall

One of the positive things in my life since the ‘shelter in place' order is my garden.  It is my refuge and escape. Who knew that the family that I love more than words can express could drive me so bananas! So, I am out in my garden much of the time just puttering around. 

Recently, I have been taking my frustration out on the weeds. February had many warm days and no rain, but the weeds are, of course, flourishing. Doesn't it always feel that way?  You can purchase a plant and baby it along knowing full well there are no guarantees it will survive. But a weed will persevere under what seems to be the worst conditions, and despite fervent wishes and efforts aimed at its demise, will look healthier every day. 

To discourage those pesky weeds I have two methods I have found to be the most successful. First is decapitation to the ground level using of a stirrup-style hoe. I use it in garden beds and loose mulch and gravel areas. I used to laboriously pull the weeds out and then till the soil, but I have since learned that leaving the roots of the weeds in the soil and using minimal tillage can actually benefit the soil health.

The second method I use on compacted areas like my decomposed granite paths and seating areas is a spray herbicide. This way I don't disturb the compacted surface when I kill the weed. With the recent research into the use of glyphosate and possible unwanted secondary effects of its use, I decided to look for an effective safe alternative for weed control.  I found some interesting data on the use of white vinegar that has acetic acid as the active ingredient.

It isn't a ‘magic bullet' but there have been some positive results with the use of white vinegar.  The white vinegar in my kitchen is only a 5%-8% concentration and considered safe as a weed killer with a minimum risk factor.  Any product with a concentration of acetic acid of 8% or more must be EPA-registered as an ‘active ingredient' as a pesticide product, and I can understand why a higher concentration is dangerous. So, I decided to give the household white vinegar a try.  No matter what concentration vinegar you use, it can be harmful to your eyes and skin, so protect yourself by wearing eye goggles and gloves.

I purchased a gallon of white vinegar in the salad dressing aisle at the grocery store. After gloving and goggling up, I filled my pump sprayer with the undiluted 5% vinegar solution and headed out to the garden on a mission.  It is very satisfying to spray all the little weed seedlings and to return the next day to brown, desiccated and very unhappy weeds. Sometimes it took more than one application, but responsible use of something better for me and the environment has great satisfaction that helps justify the extra work. 

It is important to note that you need to clean all your equipment thoroughly immediately after use. I thought I'd keep a spray bottle full of vinegar ready to spritz random weeds at will - not a good idea. Within a week the spay mechanism was corroded because the acetic acid had eaten through the gaskets. Protect your equipment and always clean it thoroughly after use.

There are multiple ‘wins' to my adventure. I know the weeds will never be entirely eradicated in my yard (there are always weeds seeds waiting for that perfect spot to light), but I now have another method in my arsenal to relieve some stress with an added benefit of feeling good about the methods I have chosen. 

Happy weeding.

References:

Northwest Center for Alternatives to Pesticides http://www.pesticide.org/vinegar_herbicides

Soil info: UC Integrated Pest Management http://ccmg.ucanr.edu/files/141617.pdf

UC Davis-Vegetable Research and Information Center https://anrcatalog.ucanr.edu/pdf/7248.pdf

During Napa County's shelter in place directive that protects everyone's health and safety, Napa Master Gardeners are available to answer garden questions by email: mastergardeners@countyofnapa.org. or phone at 707-253-4143.  Volunteers will get back to you after they research answers to your questions.

Visit our website: napamg.ucanr.edu to find answers to all of your horticultural questions.

Photo credits: "Summa"- Pixabay free picture