Rooftop Garden Classes

Homegrown Neighbor here:

Los Angeles has sprouted a very cool rooftop garden. Here where January temperatures are often in the 70′s, buildings aren’t designed to hold snow, meaning that our roofs usually can’t hold much weight. So rooftop gardens are rare.

But on the border of Little Tokyo, skid row, and a warehouse district, an old seafood warehouse rooftop has been turned into a gourmet garden atop the home of artisan food purveyor Cube Marketplace.

Full disclosure: I’m the lucky gardener. And this weekend I’ll be teaching a Fall Gardening Class and a class on new ways to use common garden herbs. For more information or to sign up for the classes click here.

The classes are part of a quarterly pop-up marketplace. Even if you don’t want to take the classes, this is an opportunity to come and check out the garden. I love watching the bees pollinate the flowers and then looking out at the view of Downtown Los Angeles and the industrial sprawl down below. It is delightfully incongruous.

Low Sugar Prickly Pear Jelly Recipe

Few plants have as many uses as the prickly pear cactus (Opuntia ficus-indica). In our climate it grows like a weed, with no supplemental irrigation, and produces a voluminous amount of edible pads and fruit. In addition to food, Opuntia provides medicinal compounds, a hair conditioner, building materials and habitat for the red dye producing cochineal scale insect. As for the fruit, you can consume it raw, dry it or make jelly. Several years ago I posted a recipe for prickly pear jelly. But the large amount of sugar in that recipe, in my opinion, covered up the subtle taste of the fruit. I’ve concocted a new prickly pear jelly using low-sugar pectin that substantially reduces the amount of sugar.

Low Sugar Prickly Pear Jelly
4 cups prickly pear juice (requires around four pounds of fruit)
1/2 cup lemon juice
3 cups sugar
1 package low sugar pectin (1.75 ounces)

1. Burn off the spines by holding the fruit over a burner on the stove for a few seconds.
2. Quarter the fruit and place in a pot. Cover with water (around 2 1/2 cups). Boil for ten minutes. Crush the fruit with a potato masher.  Update 12/5/2012: I now recommend using a food mill, though the boiling technique also works. See our post on using a food mill to juice prickly pear fruit.
3. Strain through two sheets of cheesecloth placed in a colander. Gather up the corners of the cheesecloth and give the pulp a squeeze to extract as much juice as you can.
4. Pour four cups of the prickly pear juice into a pot and add a half cup of lemon juice.
5. Mix a quarter cup of the sugar and a package of low/no sugar pectin and add to the juice.
6. Bring the mixture to a full boil.
7. Add the remaining sugar and bring back to a full boil. Boil for one minute, stirring constantly.
8. Pour into six 8 oz jars.
9. Process in a boiling water bath for ten minutes.

Prickly pear fruit (called “tuna” in Mexico) come in a variety of colors. My plants make an orange fruit that matures in August. I love the taste of the fresh fruit, but it’s a bit of an acquired taste due to the abundant seeds and the nasty spines (technically called glochids).

Unlike a lot of jelly recipes floating around the interwebs, I guarantee that this one works. It basically follows the ratios and instructions for red raspberry jelly as detailed in the Sure Jell pectin box. In my experience with jam and jelly recipes, sticking with the directions in the pectin box yields consistent results. And stay tuned for a video I shot on how to make this jelly.

Update: Green Roof Grower Bruce wrote to suggest using Pomonas Universal Pectin to reduce the sugar level of this recipe even further. I’m going to give it a try. In the meantime the folks behind Pomona’s have a very similar recipe for prickly pear jelly that uses less sugarhere (pdf).
Update 8/28/2010:  I tried the Pomonas Universal Pectin prickly pear jelly recipe linked to above. It works, and uses one cup less sugar than my recipe above. The color is also more vibrant due to the larger percentage of fruit. However, both Mrs. Homegrown and Homegrown Neighbor found the more gelatinous consistency of the Pomonas prickly pear jelly objectionable. Verdict: for now I’m going to stick with SureJell or equivalent.

Self Irrigating Pot Patent from 1917

I’ve often blogged about the convenience of self irrigating pots (SIPs), containers that have a built-in reservoir of water at the bottom. They work well for growing vegetables on patios and rooftops. You can make your own or purchase one from several manufacturers. I had thought that Blake Whisenant, a Florida tomato grower and Earthbox company founder, had invented the SIP in the 1990s, but it turns out that the idea came much earlier. Reader Avi Solomon, sent me a surprising link to a patent for a SIP, dated 1917, by a Lewis E. Burleigh of Chicago. From the patent description:

“My invention is concerned with flower and plant boxes, and is designed to produce a device of the class described in which the proper moistening and aeration of the soil in it can be easily and cheaply effected by simply pouring water into the funnel with which it is provided until the proper amount is supplied, which amount will be indicated by the overflow from a suitably located aperture in the side thereof.”

Other than the use of gravel in the water reservoir, Burleigh’s SIP closely resembles the Earthbox and SIPs I have built out of five gallon buckets and plastic storage bins.

The interwebs reveal only one detail about Burleigh, that he owned a house designed by Frank Lloyd Wright. From this one factoid I infer that he had money and a progressive inclination. The SIP idea took another eighty years to finally catch on.

For more SIP information:

Read our many posts on SIPs

And visit our SIP gardening friends, the Green Roof Growers.

If SIP litigation history fascinates you, read a preliminary injunction and memoradum (pdf) between the manufacturer of the Earthbox (Laminations Inc.) and a company they accused of infringing on their patent, Roma Direct Marketing LLC, makers of the “Garden Patch.” SIP. I’ll also note that the Earthbox folks sent Josh Mandel a cease and desist letter related to Mandel’s DIY SIP website. My editorial: lets make the SIP open source as the 1917 patent suggests it ain’t a new idea.

Asian Citrus Psyllid Eradication Program Causes Outbreak of Citrus Leafminer

Florida citrus farmers have been blanketing their orchards with pesticides in an attempt to eliminate the Asian Citrus Psyllid, an insect that caries a fatal citrus disease. But the campaign has had unintended consequences, namely the eradication of the natural predators of another citrus pest, the leafminer. According to the USDA Agricultural Research Service,

“The leafminer moth, Phyllocnistis citrella, forms channels as it feeds inside citrus leaves and, as a result, often makes the plant more susceptible to canker disease. Further exacerbating the leafminer problem is the spraying of more insecticide to combat another pest—the Asian citrus psyllid. The insecticide is killing off the leafminers’ natural enemies, allowing the pest to increase in numbers.”

The moral, in my opinion, is the same for both nature and the economy: don’t tinker with complex systems and avoid putting all your eggs in one basket, i.e. crop monocultures. Doing so is asking for “black swans” and catastrophic failure. As Nassim Taleb says, “counter-balance complexity with simplicity.” The race to layer insecticides on top of insecticides and then search for pheromonal solutions is too complex for my taste.

Appropriate Tech is the New High Tech

On his blog, the Archdruid Report, John Michael Greer has a provocative essay, “Seeking the Gaianomicon” that includes a link to a collection of 1970s/80s era appropriate technology handouts. The 190 page pdf Greer mentions (accessible at http://www.culturalconservers.org/apptech.php) includes information and how-to advice on insulation, storm windows, solar water heaters, super-insulated homes, simple photovoltaic systems and more.Greer is asking that readers spread the word about this resource. He also suggests starting your own library of appropriate technology classics. Both are great ideas.

Our blog, in fact, was largely inspired by just this type of literature in the form of a book by Sim Van der Ryn The Integral Urban House: Self Reliant Living in the City as well as other books such as Lloyd Kahn’s Shelter. Keeping with Greer’s idea of building an appropriate tech library we’ll dig up some more books and links. In the meantime, I can think of one other free downloadable book, David Bainbridge’s The Integral Passive Solar Water Heater Book, that you can access for free via the Build It Solar website at: http://www.builditsolar.com/Projects/WaterHeating/ISPWH/ispwh.htm

If any of you know of more appropriate tech books, blogs or resources worth looking at, please leave a comment.

And thanks to the Homegrown Evolution reader who noticed our oddball interest in both appropriate tech and western esotericism and turned us on to the Archdruid.

Urban Permaculture Survey/Interview

Attention urban/suburban permaculturists. I’m writing an article for Urban Farm Magazine on “urban permaculture” and I need your help. I’ve created a survey/interview for the article: click here to take the Urban Farm permaculture article survey. Please forward this link/survey to all your permaculture friends–send it out far and wide–work that Facebook! If you’re critical of permaculture you are also welcome to take the survey. Thanks for your help!

Staking Tomatoes with Concrete Reinforcing Mesh

For years we’ve been using concrete reinforcing mesh to stake our tomatoes. It’s a 6-inch square grid of wire and is used to reinforce concrete slabs. I buy it in 3 1/2-feet by 7-feet sections at my local home improvement center. To make a tomato cage with it you find a flat stretch of patio or driveway and bend the wire into a tube. I overlap it a bit and tie it together with wire.

This year, thanks to a tip from Craig Ruggless, I decided to double the height of the cages using two per plant to make them 7-feet high. As the plant grows, you simply tuck the vines into the cage, with no pruning necessary. But you do have to stay on top of the tucking, otherwise you risk breaking off stems. Since a 7-foot cage can be very top heavy I staked them deep into the ground with some rebar I had laying around. Long wooden stakes would work just as well. You could also choose to grow shorter tomato varieties. The San Marzano tomatoes in the middle of the picture above are half the height of the other two and way more productive.

Another staking option is to buy Texas Tomato Cages for $99 for six 24-inch by 6-foot cages. The advantage with the Texas cages is that they fold flat when not in use. The disadvantage is the price. If you buy your concrete reinforcing mesh in bulk, on long rolls, the price would be significantly less than the Texas Cages and I think reinforcing wire is just as attractive if rolled carefully.

I would avoid the tiny, flimsy conical cages I’ve seen for sale at most nurseries as almost every tomato plant will easily outgrow them and stems will break as they spill over the top.

For a roundup tomato staking techniques see the Santa Clara County Master Gardeners website.

And leave some comments about your favorite staking and/or pruning methods.