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April 2006

Spring Market in San Jose, Automatic Composter

This Saturday, April 1, 2006, will be the day of the 12th Annual Garden Market in San Jose. It will be held from 9 to 2 at a new location: The Mercury News, 750 Ridder Park (exit 880 Brokaw East or 101 Old Oakland North). There will be huge plant sale, with over 70 varieties of heirloom tomatoes and as many of sweet or hot peppers, plus much more. Common Ground of Palo Alto will have a booth. The event is sponsored by the UCCE Master Gardeners of Santa Clara County.

At the San Francisco Flower and Garden Show, I was offered information about many businesses and products. One novel product was a automatic compost maker that can be used indoors to compost kitchen scraps. It can handle scraps and paper waste for up to 5 people, making a high nitrogen compost every 2 weeks. It includes a heating element to help the bacteria along that need high temperature to decay the scraps. I asked about energy use, and was told it takes about as much power as a typical night light, or about 50 cents worth of power a month, or less than it costs to haul the same waste in a diesel garbage truck to a landfill or municipal composting program. The machine is 22" x 22" x 14" and plugs into a standard electrical outlet. It automatically mixes and aerates the compost as it is decomposing.

It seems to  me that this might be a good alternative for disabled gardeners. I asked if they had found a market among older gardeners, and they said they had indeed. They had expected more sales among younger gardeners, but were surprised to find the average age of  their customers was much higher than expected.

I was thinking of my Dad, who was still composting actively at 89, but gradually lost the ability to even carry his scraps out and bury them around his fruit trees. Now, when he is 99, his scraps go into the recycling bin or even, often, the garbage. Had he learned to use this composter several years ago, he might have been able to teach his caregivers how to do it, and might now still be able to compost and use the compost to help his fruit trees.

If you want to take a look at this innovative equipment, check it out at

Record Rain in SF

We passed the record today for number of rainy days in March. We've had rain for 23 of the 29 days of the month so far, and chances are we'll have a little more rain on at least one of the 2 remaining days of the month.

I have a cousin who, with her husband, started a landscaping company in Wisconsin. They soon learned that in Wisconsin, landscaping is a seasonal occupation, so they bought a heating and cooling company, which allowed for work both summer and winter.

Here in California, we count on being able to garden all year long, with only a few days at a time of truly inclement weather. But this past month, a lot of gardeners and garden professionals are having a feeling they don't often get in central California--a feeling the the weather has refused to cooperate with gardening plans for quite long enough now. A touch of what those with actual cold winters go through every year. Landscaping jobs are behind schedules; gardeners are behind in maintenance tasks, and all of us are feeling a strong need for some sunshine!

Wet soil, nasty weather. I finally found a break in the rain today to deadhead plants in the front garden and put in pea sticks for the peas in the City College garden. The peas are about 6 inches tall now, and about to develop tendrils. Pea sticks are branchy sticks that are about a foot longer than the expected height of bush peas. (So-called "pole peas" need a 5 or 6 foot tall mesh trellis to climb on.) For pea sticks to support bush peas, the branchier the better. One fork in the branch isn't enough, since the plants will have many tendrils looking for something to cling to. Look for prunings, or pieces from fallen limbs, that have several twiggy branches at the ends. When the peas are well up, push the cut ends of the sticks into the soil every foot or so among the pea plants.

New Nursery Names, Locations

Two San Francisco nurseries are changing their names.

Floorcraft is becoming Flowercraft, with a nice flower for an O. Their new website is at They are having a Garden Fair next weekend, April 1st and 2nd, 11 to 2, with free seminars and demonstrations. Flowercraft is at 550 Bayshore Blvd, between Cortland and Industrial. You can call them at (415) 824-1900.

Guerrero Street Gardens, which shares a space with The Palm Broker, is about to become Flora Grubb Nursery, at the same location. It is at 1074 Guerrero, between 22nd and 23rd Streets, and can be reached at (415) 648-2670. They are still at their old websites of and, but will soon be online at

Sloat Garden Centers have an new location at 675 El Camino Real in San Bruno. You can call them at (650) 869-6000. Maybe I will be able to give a lecture there next season?

Any other nursery news from the region? I would love to hear the scoop and will report it here.

Meanwhile, in my windowsill, my cucumbers and tomatoes are up and the leek seedlings are getting taller. Still raining about every second day and we're sick of it. Predictions were for a warmer, drier spring than last year, but so far no sign of it.

Spring Weed/Oxalis

If you are about to plant your spring garden, you may be looking at the weeds that have come up during winter and feeling a bit overwhelmed. One weed in particular, drives local gardeners crazy. We call it Bermuda buttercup, or Cape oxalis, yellow oxalis, or sour clover. It's scientific name is Oxalis pes-caprae, showing that it is a relative of our native redwood sorrel, which is Oxalis oregana. The weedy oxalis is, however, not native to California, but to the Cape region of South Africa.

This weed is dormant in summer, then emerges from the ground in the fall, when it looks kind of nice covering the ground with its trefoil leaves that remind us of clover. But by the time that the plant has bloomed, with its rather pretty, yellow, funnelform flowers, we realize that it has taken over whole swaths of the garden, and that spring bulbs and other perennial flowers, not to mention tender seedlings, are going to have a tough time competing. (And, by the way, no this plant is not a legume, like clover, that adds nitrogen to the soil. The leaf resemblence is superficial only.)

This weed reproduces from many small teardrop shaped bulbs. If it is pulled when it is young, say, before it flowers, you may be able to deplete the bulbs so they have less energy to regrow, but hand eradication usually requires a combination of pulling and digging to remove bulblets. As you pull out large oxalis plants this spring, resolve to act sooner next year, in the fall, so that the plants can't store up food for next year.

The only good news, at least so far, is that no one has been able to proove that those yellow flowers ripen seed. In fact, a member of the California Native Plant Society has put out a $100 reward for anyone who can proove the plant reproduces by seeds. Let me know if you have proof, and I will tell you who to contact. In the meantime, hope your weeding goes well!

Best Garden Show Comment

I was talking to a garden designer in the garden he had designed for the San Francisco Flower and Garden show when a small boy walked over and asked loudly, pointing at a plant behind him: "Is that blue-eyed grass?"

The designer replied that it was indeed blue-eyed grass.

The young man, who was probably about 6 years old, replied firmly, "That plant is NOT Sisyrinchium!"

The designers and I smiled and he said, "Yes, that is Sisyrinchium, it's blue-eyed grass."

The boy said, "No it isn't. It is NOT Sisyrinchium!" By this time, his mother caught up with him, and as the adults around all chuckled, she escorted him gently out of the garden, saying, "Please forgive my son's enthusiasm."

I have to say that I loved this kid's enthusiasm and his ability to pronounce Sisyrinchium.

Next Lectures/Recovery from Hail

Today was the last day of the Spring session of Vegetables and Herbs at City College. We were able to go into the garden and plant out some hail damaged lettuce seedlings. They had been in the lath house, where I thought the strips of wooden lath would protect them from the hail, but they still had about half of their leaves broken or torn. We removed the leaves with the worst damage, and hope for the best (and for no more hail).

HailhenchicksStill noticing more damage, a shredded tulip here, ruined hen and chicks there. Here are pots showing both along with a shredded cineraria. (Click on the image to enlarge it.)

We celebrate the end of each of the vegetable classes with a potluck, and this one was one of the best. Students brought some mighty fine dishes that use some of the crops we studied, from baked pasta dishes, to salads, fritattas, and appetizers.

The next vegetable and herbs class (111G) starts on Saturday, April 8th, and meets 6 times, through May 20th. You can learn more about it and register on The site may say there is a prerequisite class, but there isn't a formal requirement, though some experience with plants and gardens is a help. (The most basic gardening class I teach is 101, which will be offered again in fall or spring of the next school year.)

My next public lecture will be on Saturday, March 25th, at Common Ground store in Palo Alto. It is at 10:30 A.M. and will be on the subject of Mediterranean Climate Food Gardening. You can find out more about it on the website

I will be talking on the same subject, though a somewhat shorter lecture, at Sloat Garden Centers in April. I will be at the San Francisco Sloat (the one across from the Zoo) on April 12th, at 6:30 P.M., and at the 401 Miller Avenue store in Mill Valley, at 10 A.M. on April 23rd. You can learn more about those talks at their website, at

I'm having fun with this lecture subject, which encompasses geography, climate, the history of foods and agriculture, and delicious recipes, and gives us a fresh perspective on how to think of our gardening year here in our California mediterranean paradise. (Well, paradise except when it hails on our gardens.)

(When I get too upset about what the weather is doing to my garden, I remember the words of one of my favorite garden writers, Henry Mitchell, who wrote:

"It is not nice to garden anywhere. Everywhere there are violent winds, startling once-per-five centuries floods, unprecedented droughts, record-setting freezes, abusive and blasting heats never known before. There is no place, no garden, where these terrible things do not drive gardeners mad."

Then he said:

"Now the gardener is one who has seen everything ruined so many times that (even as his pain increases with each loss) he comprehends--truly knows--that where there was a garden once, it can be again, or where there never was, there can yet be a garden so that all who see it say, 'Well, you have favorable conditions here. Everything grows for you.' Everything grows for everybody. Everything dies for everybody too."

The above quotes are from The Essential Earthman, Henry Mitchell, Indiana University Press, 1981.

I have been seeing only snippets of the Garden Show for the past few days, but finally, tomorrow, I will be able to spend a whole day there and see what is new.

Flower & Garden Show Preview

Last night I attended the Gala that opens the San Francisco Flower and Garden Show. I think there are a number of gardens that are particularly interesting this year--more than in recent years.

The SF GRO garden, made to represent the essence of urban food gardening and community gardening, is very charming, including, as it does, vegetables, herbs, and flowers in raised beds, a (nonworking, I imagine) beehive, a compost bin (to which some of the other exhibitors have already contributed), a graffiti sign by a local graffiti artist, and a bottle tree. Yes, a bottle tree. It is a custom of African American gardeners in the South to put bottles on the bare limbs of a tree "to catch evil spriits." This one, done by a local artist, has flowers etched on the bottles.

In many gardens, recycled materials are used well, including the garden by Urban Resources, in which everything is recycled but the plants and others that include recycled paving, retainng wall, and sculpture materials. Some of the sculptures, recycled and otherwise are whimisical and wonderful. There are garden lights in one garden made from pairs of kitchen drains. The University of Arizona garden has spectacular sculptures and dramatic plants.

In other gardens, there are tunnels with waterfall walls, innovatiove paving, and, of course, a wide variety of ornamental plants, most with labels.

Be sure to check out the Sunset display, in the South Pavillion (outside of the main garden area), which has succulents in containers on a patio back to back with a meadow based on a new lawn substitute which is a Carex (a sedge).

More details and plant names in future posts. I will be back at the show three more times before it is over.

Learn more about the show at

Writing about Weeds

Today I have been writing a lecture about weeds to present to a Master Gardener audience on Thursday. So I have been reading about Yellow Star Thistle, a weed that is believed to have entered California in the mid 1800s in a contaminated batch of alfalfa seed from Chile. But the plant originally came from the Mediterranean, so I guess it got to Chile first, then here. It thrives in a mediterranean hot dry summer region, and so has galloped across California. We hate it because it has sharp spines behind the flowerheads, because it dominates a landscape, using up water that native wild flowers could have used, and because it is poisonous to horses. Horses that eat quite a bit of it (1 to 2 times their body weight) have brains permanently damaged in a way that prevents them from being able to eat or drink.

So, its a nasty weed that now infests 22% of the state of California, or about 20 million acres. We combat it with goats (they can eat it safely), with several insects imported from Greece that live only on this plant, with carefully timed mowing, and with controlled burns. No happy ending in sight, but a lot of thought and energy is now going to trying to reclaim land lost to yellow star thistle. You can read more about it at Their website includes the entire text and the photos from the book Invasive Plants of California's Wildlands. Search for it by its common name or by Centaurea solstitialis.

I have continued to peer at plants damaged by the hail. Many are now showing pale lesions on the leaves that are caused by the impact of hailstones. I am also frequently seeing pale streaks rather than spots, and I have never seen this before. Clearly the hail was falling so hard that it streaked across the leaves, rather than just hitting and bouncing. Often a streak ends in a tear. Alstroemeria (Peruvian lily) is another species that lost many leaves to the hail.

What a mess the hail made!

Hailccsf_2 Shredded cineraria daisy, nasturtium, potato, even chunks cut out of the fat leaves of a hen and chicks succulent. There is a skirt of leaves around the base of a number of trees in the neighborhood, all knocked off by the hailstones--most of which were as big as garbanzo beans.

A mat of lumpy ice covered the demonstration garden at City College of San Francisco well into Saturday, the day after the hailstorm. The next day, the hail and snow froze together to make a lumpy ice sheet on the bare ground around the bases of plants. Lifted them off and hope for the best. It hailed again a bit today, but nothing like Friday night. As with a frost, I am leaving the plants alone for a few days to see what will recover.

Watching how long the ice took to melt in my back garden taught me where the coldest places are. They are next to the fence on the garden's east side and, coldest of all, by that east fence and next to the house, a shady corner where ice is still unmelted on Sunday!

It isn't that cold out. Even during Friday night's thunder and hail storm, it was only about 40 degrees F. Today it is about 50. But the soill temperature on Saturday was barely above freezing, from having ice melting into it, I presume. The sun is shining, after repeated rainy spells all day today.

Getting ready for the garden show. I will be at the Gala on Tuesday and viewing the gardens again at a Press Reception on Wednesday, then speaking at the show on Friday at 6:30.

And Now Hail!

Announcing itself with bright flashes of lightening and loud claps of thunder, a hailstorm fell tonight. What a racket it made. Our poor cat was cringing in a chair, his eyes wide, tail tucked under. I was thinking about the plants. There was over an inch of snowy hail in pots on the porch. It was dark and cold, but I dumped the stuff out of the pots of plants I know aren't hardy to frost.

Hailporch I wasn't sure of a couple of plants, so went upstairs to check their hardiness. Sunset's Western Garden Book was the first reference I picked up. Sunset zones are great for understanding the climate you live in. But when I tried to find out whether a particular plant can take the cold temperature it was just exposed to, I had to see which Sunset zone it is hardy to, then look up that zone and read through the text about it until I found out its coldest temperatures. (Click on the pictures to see them larger.)

Doing this a couple of times made me realize the value of the USDA Plant Hardiness Map. Simple. Easy to remember. USDA Plant Hardiness Zones consist only of the coldest temperature a plant can survive. Zone 10's average coldest temperature is 30 to 40 degrees F, Zone 9's is 20 to 30, and so forth, each one 10 degrees colder. Once you learn the zones, you know the coldest temperatures without further reading. (USDA Hardiness Zones appear in many books and plant catalogs.)

You can see the USDA Plant Hardiness Map at  This is in the site of the US National Arboretum. Click on "Go to the Map."

In any case, I will report on the condition of the plants in my garden tomorrow. One thing I know is that the chard, wild onion, and garlic chive leaves will be marked with little white dots--injury caused by the hailstones. How did your plants fare in this weather?

HailcinerariaHere you can see the damage to a cineraria daisy that was blooming before the hail hit it.