Pokeweed--A huge and Toxic Weed

In my SF Chronicle Column for November, I reported on a weed that has been sighted in San Francisco. It's a native in the  Eastern part of the U.S., so I was surprised to find it here, but there it is. I also saw one down the Peninsula this summer, though I forget just where. 

The plant is large, 4-10 feet tall, and most parts and stages of it are toxic to most mammals. I described it in my column, but was unable to get a photo of it into the print version. However, I can show a photo here. This is an image of a stem of berries. Botanists call this kind of flower or fruit-bearing stem a raceme. The berries are dark purple. When they are ripe, their stems and the longer central stem of the raceme are usually bright pink. The stems of ripe berries are the most recognizable parts of the plant. 

Pokeweed berries

Photo by Andra Sadoun

You may find it surprising, given the toxicity of this plant, to know that it has long been a part of the diet of rural people in the South and eastern-central parts of the U.S.one of the young greens gathered and eaten in spring.  Only the leaves of very young plants are eaten, and they must be boiled two or three times, with the boiling water drained off of them between boilings and after the last one. This dish is called "poke sallet." (It important to know that the word "sallet" derives from an old English word that meant cooked greens, not salad, as the raw leaves would be toxic.)

The berries are toxic, and eating only a few has killed small children. Though some say the seeds are the most toxic part, it hardly seems worth the risk to try them. Birds seem immune to the berry toxin, so the fruit is eaten by many kinds of birds, including Northern mockingbird, mourning doves, and cedar waxwings. Raccoons and possums may also be able to eat the berries, though most mammals cannot.

The most toxic part of all is the root. The plant is perennial, likely to regrow from last year's roots, so the best way to get rid of it is to dig it out. Wear gloves, as the toxin can enter through skin. Then pick up any fallen berries you see, and watch for seedlings. (The young plants are sort of nondescript, with large oval, pointed leaves.)

How did the weed get here? Presumably from bird-planted seed, but it's possible the seed was assisted by some other form of transportation. It could have stowed away in tire treads or shoe treads. While there are domestic varieties, are grown as ornamentals, their leaves look different from the wild plant. (The ornamental varieties are  ‘Silberstein’, which has pale, cream-colored leaves with green spots, and ‘Sunny Side Up’, with yellow-green leaves.) The ones being found in the Bay Area seem to have normally green leaves, meaning are not escaped ornamentals.


Fish with Seafood Sauce and Shredded Raw Beet Salad

The wild onion in the following recipes is shown below. The first image shows the plant, which grows from late fall to spring, usually as a weed in gardens and wild urban places in the San Francisco Bay Area. It could be made with ordinary green onions. If you live in the Eastern US, you might have access to a plant that is native there called ramps, which is similar and could be used instead. (Ramps don't grow in the West.)

Wild onion IMG_3026 copy 2e

The second image shows a close up of leaves and flowers, so you can see the ridge, or keel, on the underside of the leaves and also that the flower stem is triangular in cross section. Note that there is a green line down each of the petals.

Winter crop scans 001 copy2

Fish in Seafood Sauce (Adapted from the book From Sea and Stream, by Lou Seibert Pappas, 101 Productions, 1986) (The wild onion referred to in this recipe is Allium triquetrum, a Mediterranean escaped species that is a weed in California gardens. Please only eat weeds if you are sure of your identification skills.)

8 medium mushrooms, sliced                                               3 tablespoons cornstarch

2-3 green onion or wild onions, cut up                                 1/4 teaspoon salt

1 Tablespoon butter or margarine                                         a dash of nutmeg (that's like half a pinch)

1 cup milk (nonfat is fine)                                                       1/4 cup dry white wine

3-4 ounces of small peeled shrimp or other seafood

1 to 1 1/3 pounds rock fish like snapper (or swai, which is also called white roughy and basa)

Set oven for 400° F. Spray-oil or grease an approximately 9x12 oven proof casserole or pan. Arrange pieces of fish in the casserole in a single layer. In a small skillet, saute mushrooms and onion in butter or margarine until soft. In a small saucepan, put the milk, then add to it the cornstarch, salt, and nutmeg. Cook the milk mixture, stirring often, until the sauce thickens. Stir in the wine, mushroom/onion mixture, and shrimp or other seafood. Pour the sauce over the fish. Bake, uncovered, for 15-25 minutes, until fish separates easily with a fork. Good served over rotelli pasta. Makes 3-4 servings. 

Some photos follow, showing preparation and serving of the dish:

Cutting up the wild onions and the mushrooms. The fish is in the casserole.

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The casserole ready to bake.  Wild onion IMG_2926 copy

Fish with seafood sauce served over rotelli pasta. Wild onion IMG_2927 copy

The recipe calls for shrimp, but in this case the dish has been made with cut-up cooked mussels, purchased frozen.


Shredded Beet Salad (Adapted from Farmer John's Cookbook, John Peterson, Gibbs Smith, 2006)

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2-3 cups coarsely grated raw beet                              1/2 teaspoon Dijon mustard

1/4 cup olive oil                                                           2 Tablespoons white or rice vinegar

1 Tablespoon finely chopped  shallot (or white part of wild onion , scallion, or chopped bulb onion)

1 small clove garlic, finely minced (1/4-1/2 teaspoon)

1 Tablespoon chopped fresh dill leaves or one teaspoon of dried dill weed)

salt and black pepper if desired

leaves and flowers of wild Mediterranean onion for garnish

             Put the grated beets in a large salad bowl. In a small jar with a lid, combine the rest of the ingredients. Put the lid on and shake vigorously to mix ingredients. Pour the dressing over the beets and toss with two spoons until well coated. Adjust flavor if needed. The salad is now ready to eat, but it's even better if marinated in the refrigerator for at least an hour. Keeps in the refrigerator for several days.

  Beet salad IMG_4522 copy

More on Early Blight of Potatoes & Tomatoes

(See photos in the previous post)

In my last post, I reported having seen some potato plants in San Francisco with what looked like early blight, a disease caused by the fungus Alternaria solani. I remembered from my research for the book Controlling Vegetable Pests, which I wrote in the early '90s, that this disease is not common here in California, but much more so elsewhere in the US. I wrote then that it is "less common in arid regions of the West, although overhead irrigation and frequent heavy dew promote disease in these areas." It showed up the week after we had an unusual June rain, and in a garden that has frequent fog. But the question is: Where did the spores come from?

My first thought was that someone had planted potatoes from the grocery store. These could carry the spores, even without symptoms, or could have had dark lesions with underlying brown or blacky corky rot from spores that grew on their surfaces. However, the gardener assured me that these were purchased at a nursery as certified disease-free.

So the spores must have blown in from a nearby garden or were carried in the rain. Then they landed on potato leaves that had some injury, at a time when the temperature and amount of hunidity were right for them to start growing, and the rest is history. The ideal temperature for early blight spore growth is 75-80 degrees F, but the symptoms develop fastest at 70 degrees. 

This disease can also infect tomato, and, occasionally, eggplant or pepper. Wild relatives of these plants are also susceptible. On tomato, the leafe symptoms, the bull's eye spots, are the same as on potato, and there may be sunken lesions on older stems. In additon, there may be excessive blossom drop (common here anyway due to cold nights) and leathery, sunken, dark brown lesions on the stem end of the fruits.

If this disease shows up in your garden, take the plants out of the garden. (In San Francisco, they can go in the Green Bin, since the municipal composting system will heat up enough to kill the spores.) If potato plants have formed tubers, eat them up soon, as they may decay in storage. Don't store them where you will kep other, healthy, potatoes later.

The spores can germinate in plant material from infected plants as long as it has not completely decayed, so pick up every bit of the plant and dig up most of its root. Do not save seeds from tomatoes that ripened on infected plants, as the spores can hide in the seeds.

Remove any solanum weeds that are growing in your garden, as they can harbor the disease. (They have flowers similar to those of tomato, but usually with white or pale lavender petals, and have clusters of small, inedible berries that turn black when ripe.)

Plan not to grow tomatoes or potatoes in the place where infected plants grew for two to three years.

When you do plant potatoes or tomatoes, provide your plants with adequate water and fertilizer and avoid getting water on the leaves of tomato'potato family plants. Start examining them when they are about a foot tall to be sure they do not have symptoms. Prevention is more successful than cure when it comes to plant diseases, but if you have had the disease, or if you see the first lesions it is causing, you might try the fungicide Serenade, which is based on a soil bacterium. Follow directions on the label, including repeated sprayings as it directs. (If you are spraying after seeing lesions on a leaf or two, pick off those first infected leaves before you spray.)

May early blight of tomato or potato not darken your door, or the leaves of any plants you are growing to produce food!

A Frolicsome Weed

I wrote about this weed in my December 31, 08 SF Chronicle column, Golden Gate Gardener. Tried to give you a link, but will need some help from the blog administrator to do it. I can tell you that you can see the article at sfgate.com, click on "Living", then "more Home and Garden," then "Golden Gate Gardener."

In any case, here is the photo2008 December 032 copy2. The plant has pretty leaves. The reader thought maybe it was cilantro.

But no, the flowers give it away. This plant is related to Dicentra, bleeding heart. It is called Fumaria capreolata, or white ramping fumitory. To ramp is to climb up, which it does by tendrils. (You can see a forked tendril on the lower right.) It climbs all through other plants and if you pull on it, it breaks, so you have to reach down through your garden plant and find the base, so you can pull it by the root. It's an annual plant only, so pulling it will kill it, but if it drops its seds, then you will have it next year, and for several more, probably. It's kind of pretty in a closeup, but when you see a whole mass of it, it is untidy and kind of nondescript.

I have been working hard on a writing project recently, but plan to get back to blogging now, at least once a week. I have photos of what has been happening in the City College garden and will be posting them and writing about them. Stay posted for more postings.

A Weed to Watch Out For

Mid_april_2008_068_copy My Golden Gate Gardening column in today's SF Chronicle (www.sfgate.com) was about Nothoscordum gracile, a weed to watch out for in your garden. I thought I would put a few photos in this post, for those who wonder if they have it and to help you understand what is going on underground if you do have it. The plant, shown at left, has white flowers that look a little like a brodiaea. It blooms most actively in summer. The leaves are strap-like, gray green, and do not have a midrib. This plant is not edible and does not have any scent of onion or garlic. The plants can be easily overlooked, but the best way to control them is to remove the first one you see, digging carefully to get all of the root and the bulblets, even discarding a handful of soil to be sure you got rid of all the bulblets.


Here is a mature bulb with its many bulblets, each the size of a grain of rice. The youngest ones are white, so they stand out well against the soil, but the older ones turn brown, and are very difficult to see. The bulbs are usually very deep in the soil--as deep as your shovel can reach. Be sure your shovel blade is straight up and down when it enters the soil, or you may cut the stem of the plant, leaving the bulb unmolested in the soil.

Mid_april_2008_069_copy The problem with leaving some of the bulblets in the soil is that they will all germinate into small plants. Incompletely digging a Nothoscordum bulb, and then turning the soil in the bed can spread the bulblets all over, so that soon you will practically have a lawn of the plants. I am combating this weed now in a vegetable garden, digging out mature bulbs and also digging the smaller plants carefully to be sure I have removed the attached bulbs, and am ruing the day I tolerated the first plant of it. Don't make the same mistake.

The other weeds: Wildland Weeds

Some weeds escape mainly in gardens. Others may be weeds in gardens, or may not, but are able to grow in undisturbed, or relatively undisturbed wild habitats. A prime example is Algerian Ivy, which can cover the ground under redwood trees and climb them, sometimes causing them to die. Most plants not native to the redwood forest woudn't be able to grow there, but this one, from North Africa and the nearby Canary Islands, just takes over.

As the information about these pest plants gets out, gardeners who want to do the right thing begin to check whether a plant could be a wildland invasive before they plant it. This is a good thing, but going online to check can be tricky. If a search for the plant's name with the word "invasive" or "wildland weed" turns up a lot of hits, you still may not be clear whether the plant is invasive where you live.

In California, the best site to check for this information is the California Invasive Plant Council. Here is a link to their site:

www.cal-ipc.org California Invasive Plant Council. This nonprofit seeks to reduce the escape of non-native invasive plants into California’s wildlands. The entire book Invasive Plants of California’s Wildlands, with both text and photos, is available on their site.

If what you want to do is find out where wildland weeds are being combatted near you, with the thought you might volunteer to help, this next link is for you:

http://www.ice.ucdavis.edu/nrpi/  This is the Natural Resource Project Inventory. If you scroll down and click on "county" and then select your county and click on "submit" you will find out where the nearby action is. These projects welcome volunteers and can be fun and a good place to make new friends.

I've been weeding a lot lately

This is the season when our gardens often look like the weeds are winning. In our mediterranean climate, winter rains bring weeds, many of them natives of The Mediterranean (the European or African lands that border the Mediterranean sea) so they are used to this winter rain-enabled life cycle.

While it is tempting to think of weeds en masse, there are a number of reasons to identify them. The skillful gardener notices new weeds and learns how to fight them before they get a root-hold, and knows which of the usual cast of weed characters have underground structures (like bulbs or running roots) that must be removed if one is to get rid of them.

Identifying weeds can be difficult, but if you can get as far as common name, you can learn quite a bit about your weeds on the following two web sites designed for California gardeners. And, knowledge, as they say, is power.


Find weeds by common or scientific names, read about them or see photos. Look at the national weed list & at the California weed list. Check out the pdf of the Noxious Times, the California Dept. of Food and Agriculture weed management newsletter.


This site offers a weed photo gallery that is searchable by common name. From here you can also go to the same weed list searchable by scientific name or by plant family name. You can also read about weeds that cause problems in turf.

Oxalis Attacks Bay Area

I've been getting a number of letters about Cape oxalis (Oxalis pes-caprae), a weed that is now in full bloom in San Francisco. Also known as Bermuda buttercup, this South African native wildflower is has pretty yellow flowers that are cheery to see blooming on weedy road verges, but in a garden, it is a terrible pest. It grows in fall, blooms about now, and then dies back in later spring.

Cape oxalis grows from small tear-drop shaped bulbs that are dormant in summer, so many an unsuspecting gardener has planted in summer without realizing it was there. When it does appear, some think it is a clover, since it has trefoil leaves like a clover, and hope it will add nitrogen to soil. It won't. I have written my February 21st S.F. Chronicle column on this weed and how to (attempt to) get rid of it, so check out sfgate.com on that day.

Oxalis gets its sour flavor from oxalic acid, a substance that is also found in French sorrel, and, to a lesser extent in chard, beet greens, and spinach. We shouldn't eat great quantities of a plant that contains as much oxalic acid as Oxalis, but it is a nice nibble or could be added to salad in small amounts. In fact, I just read an article by a Greek writer about using Cape oxalis with French sorrel and other wild greens in soup or savory pie. I shall try to get recipes!

Less Toxic Herbicides?

I have often been asked whether vinegar was a good weed killer. I have thought it had potential, but it has been my understanding that the weak vinegar solution we use in cooking is probably not strong enough to work well. Now, recently, I have been sent a sample of a weedkiller, containing 8% clove oil, 90% vinegar, and 2% lecithin. It is called Perfectly Natural Weed and Grass Killer. I have been using it on the weeds in the sidewalk cracks in front of my house. It has worked well on annuals, and has killed some of the perennials, like dandelions, but a couple of those have recovered. I tried it on them again today, a third time, ever hopeful.

The vinegar in Perfectly Natural Weed and Grass Killer is 8% acetic acid, quite a bit stronger than ordinary vinegar, and, no doubt, harmful even to get on ones skin in that concentration. The lecithin is a food product used to emulsify, that is, mix oil and water, so it probably just keeps the clove oil in suspension. Interestingly, the clove oil is listed as the active ingredient, the vinegar as an inert, or inactive ingredient, though I'm sure it has an herbicidal effect.

My web research tells me that this is a Canadian product, and that Home Depot will be carrying it in the U.S..  A Colma Home Depot worker tells me they don't have it or know about it, but that they have had several queries about it this week.

A similar product mentioned on the web is Burnout II, which is 4% clove oil, and also contains vinegar, citric acid, lecithin, sodium laurel sulphate, and mineral oil.

A study that compared several herbicides, including the herbicide Roundup (which contains the synthetic compound glyphosate) and Burnout II, found that these two products produced similar results, however while the Roundup cost $80 an acre, the Burnout II cost $1200 an acre. This is dramatic. Though I didn't buy my Perfectly Natural Weed and Grass Killer, I supect the price of it is similar to Burnout II, however, since I am using it only on weeds in cracks where I can't pull them, I won't need much of it to do the trick.

In summary, either of these vinegar and clove oil based herbicides are reasonably effective unselective herbicides and, unlike Roundup. they don't introduce synthetic chemicals into the environment. If I can figure out where to buy more of this kind of herbicide, I will do so.