By Penny Pawl, UC Master Gardener of Napa County
Three years ago, I wrote an article about creating African keyhole worm-compost bins in my garden beds. This summer it was time to harvest compost from two of the bins.
I used garbage cans with ¼-inch holes drilled in the sides and bottom so the worms can go back and forth. As they move about, they take some of the compost with them and spread it in the garden bed.
Mine are all raised beds. The bins were installed after hardware cloth was added to the bottom of each bed to foil gophers. With time, the hardware cloth will rust and need replacement.
Keyhole gardens originated in Africa when people created kitchen gardens using materials they had lying around. The design is circular with a keyhole-like entrance. A worm compost bin made out of chicken wire or other materials is placed in the center, and the gardener puts kitchen waste in the bin. When the compost is ready, it is spread over the garden.
The first garbage can I checked was half full of compost. I transferred all the uncomposted material on top to another bin. Then I prepared a mesh bag (the kind potatoes come in) full of my red wiggler worms' favorite foods, like bananas, lettuce and melon rinds. I placed this bag on top of the finished compost as a lure. Slowly the worms and sow bugs started moving from the compost into the mesh bag. These worms are expensive and I didn't want to lose any. Luring most of them into the mesh bag took about two weeks.
Why do I want the sow bugs? They also eat decomposing material and leave their droppings, which are as beneficial to plants as worm droppings are. On one online forum I follow, a worm composter was looking for sow bugs to add to his bin. I have found that they move in naturally.
I put the composted material on a screen over a tray. In the tray I put new damp bedding: newspaper, cardboard, old leaves, straw. Neither red wigglers or sow bugs like light, so they will leave the compost and move into the new bedding. Then I can sift the compost to get out any large pieces that haven't fully broken down. These big things go into the bottom of the new bin.
I move the sifted compost to a large, long tray in my hothouse to dry. If stored damp it will mold.
The biggest problem I have encountered is that tree roots also like keyhole gardens. I wasn't aware of this problem when I built the beds, and I had to cut the tree roots out. Also, my arms aren't long enough to reach the bottom of the garbage can so I eventually need help getting all the finished compost out.
Once a bin is empty, I use the layer method to build a new bin, alternating torn damp newsprint, dried leaves, rice hulls, coffee grounds and a dash of chicken manure. The worms and other critters in the bin will mix these materials, which should be as damp as a wrung-out sponge. Usually, I top off the layers with banana peels or old lettuce. On top of all that, I place a piece of black plastic and put the lid on the can.
Once I see that the worms are settled and eating the items in the can, I start feeding them my kitchen garbage. Three garbage bins have yielded 15 gallons of worm gold, as we gardeners call it. I will spread it around my yard to feed all my plants this fall.
If you would like to learn more about composting, take a look at “Backyard Composting,” a video that several Master Gardeners and I produced in partnership with Napa County Library. You can find it on YouTube.
Food Growing Forum: Napa CountyMaster Gardeners will present a discussion of “Cane Berries” on Sunday, November 14, from 3 p.m. to 4 p.m., via Zoom. Register here to receive the Zoom link.
Got Garden Questions? Contact our Help Desk. The team is working remotely so please submit your questions through our diagnosis form, sending any photos to email@example.com or leave a detailed message at 707- 253-4143. A Master Gardener will get back to you by phone or email. For more information visit http://napamg.ucanr.edu or find us on Facebook or Instagram, UC Master Gardeners of Napa County.
- Author: Penny Pawl
by Penny Pawl, U.C. Master Gardener of Napa County
Over the years, many people have attended compost workshops conducted by the City and County of Napa and the Napa County Master Gardeners. I have been teaching the worm compost classes and always wonder if the people who made worm bins got all the information they needed to clean the bed when the time comes.
Worms are important composters as they eat 90 percent of what is given them. Their castings(aka worm poop) provide a balanced fertilizer for plants. Over time, they will eat newsprint, dried leaves, straw, coffee grounds, eggshells and various fruits and vegetables.
Sometime after you create your worm bin and worms have been chomping on your kitchen scraps, you will need to separate the castings from the other things you have been feeding them. When you do this, you will see that the worms have transformed most of the newsprint and other bedding into a fine soil-like product.
If you are still using the 18-gallon tub you received at the workshop, you can move the finished compost to one side of the container and build new bedding on the other side. Feed the worms only on the new side and, over time, the worms will move into the new bedding. Then you can remove the old bedding to dry and remove any unfinished compost.
Another approach is to remove all the old bedding and build a new bin. However, you want your working worms to move into the new bedding. The easiest way to achieve this is to put the old bedding on a screen on top of the new and expose it to light. Worms are light sensitive. To escape the light, they will move down into the new bedding. I tried this in one large worm bin years ago and the worms had relocated in a half hour.
I compost in much larger containers. My method for harvesting the castings is to remove all the finished bedding to a wheelbarrow and rebuild the bedding with new materials. I use the “lasagna” method of layering materials. Remember to dampen all the materials as you layer them. They should be as moist as a wrung-out sponge. Worms breathe through their whole bodies and need to be kept moist.
To coax my worms out of the old bedding so I can put them back to work, I use the mesh bags that potatoes and apples are sold in. I fill those bags with new bedding and favorite foods of the worms and bury the bags in the old compost. In a few days, the worms will move from the old compost into the bags, and I can then transfer the content of the bags to in the new bedding. Another method is to place a large screen with old compost on it over the new bin and let the worms sort themselves.
Once the worms have moved out of the old compost, I dry the compost in the sun and then sift it. Any large pieces go back into the bin. If the compost is clumpy, I put it on a tarp or and walk on it to break it up before sifting.
Make sure the compost is dry before storing it. Otherwise, it may mold.
You can spread the compost directly on garden beds. I usually sprinkle it around the plants and water it in. I also put a little scoop in planting holes to give the roots of new plants a boost.
Fall Faire: U.C. Master Gardeners of Napa County's second annual Fall Faire will take place on Saturday, October 5, from noon to 4 p.m., at 1710 Soscol Avenue in Napa. Tickets are $5 for adults. Children 15 and under are free with an accompanying adult. Purchase tickets online with a credit card. Cash and check only will be accepted at the door. Find more on the Fall Faire at http://napamg.ucanr.edu/fallfaire/.
Next workshop: U.C. Master Gardeners of Napa County will hold a workshop on “Stinking Roses and Edible Alliums: Grow These Essentials for Your Kitchen” on Saturday, October 12, from 9:30 to 11:30 a.m., at the University of California Cooperative Extension, 1710 Soscol Avenue, Napa. For more details & online Registration go to http://napamg.ucanr.edu or call 707-253-4221.
The UC Master Gardeners of Napa County are volunteers who provide UC research-based information on home gardening and answer your questions. To find out more about upcoming programs or to ask a garden question, visit the Master Gardener website (http://napamg.ucanr.edu) or call (707) 253-4221 between 9 a.m. and noon on Mondays, Wednesdays or Fridays.
- Author: By Penny Pawl, U. C. Master Gardener of Napa County
Spring is here and it's time to clean and refresh your worm bed. You can harvest that precious gold—the worm castings—and use it to feed your plants.
Years ago, I graduated to large compost bins for my worms. These bins need cleaning about every two years. If you are using a small container, you may need to clean it more often. I do add new bedding to the bins whenever the bedding gets about halfway down.
If you have a small worm bin, you need to harvest the vermicompost, get the worms out and then return the worms to the bedding. There are several ways to do this.
In the past, when I had a small bin, I would remove the whole pile to a temporary container. I would put the worms and their castings on a screen with a mesh large enough that the worms could move through. I would place the screen over moist new bedding. Then I would expose the whole thing to a light bulb or to sunshine. Since worms are light sensitive, they would wriggle away from the light and into the fresh bedding.
Another option is to use the plastic net sacks that onions and potatoes come in. Fill a sack with fresh, moistened bedding and put some of the worms' favorite foods inside. Then put the sack on top of the vermicompost and the worms will move into it, leaving the vermicompost behind for your use.
This method takes a little longer, but it's how I harvest my big bins. When the sack is full of worms, I dump it back onto the new bedding and the critters go back to work.
If you have big bins, you will have a bigger harvest and you need to prepare for it. Gather all the materials for the bedding: torn newsprint (no shiny coated paper), dried leaves, plain cardboard, straw, rice hulls, shredded paper. It feels good to put my old tax records in there.
When I have the bedding ready, I take the bin apart and set aside any uncomposted material. I put the composted material in a wheelbarrow so I can begin the process of separating worms and compost. I put the uncomposted matter back in the bin and then add the new materials. I don't try to mix them. Instead, I make a big “lasagna” of Iayered materials. As the worms eat their way through it, they do the mixing. Be sure to moisten all of the dry materials first, especially cardboard. When the bin is full, water it well. If the materials sink a bit, just add more.
I place a tarp over the castings in the wheelbarrow and put one or two of my sacks full of worms into the bedding. Every few days, I check the sacks and move the worms and contents to the new bin. Sometimes I add new worms at this point, purchased from a bait shop.
Once the worms have departed, I sift the compost to remove big items like sticks or peach pits. Then I put this sifted vermicompost into large pans in the sun to dry. When it's dry, I transfer it to a lidded storage container. (I use a garbage can.)
Scatter the castings around potted plants and in your beds, and your garden will thrive.
Workshop: U. C. Master Gardeners of Napa County will conduct a free workshop on “Worm Composting” on Saturday, March 19, from 9 a.m. to 11 a.m., at the University of California Cooperative Extension office, 1710 Soscol Avenue, Napa. Learn how to turn yard and kitchen scraps into rich compost to use as a soil amendment or garden mulch. Register here. No phone registration.
Master Gardeners are volunteers who help the University of California reach the gardening public with home gardening information. U. C. Master Gardeners of Napa County ( http://ucanr.edu/ucmgnapa/) are available to answer gardening questions in person or by phone, Monday, Wednesday and Friday, 9 a.m. to Noon, at the U. C. Cooperative Extension office, 1710 Soscol Avenue, Suite 4, Napa, 707-253-4143, or from outside City of Napa toll-free at 877-279-3065. Or e-mail your garden questions by following the guidelines on our web site. Click on Napa, then on Have Garden Questions? Find us on Facebook under UC Master Gardeners of Napa County.
The process I use is called sheet composting, and it is simply a method of building a compost pile in place. You can not only use this procedure on well-turned vegetable beds but also on a lawn, or part of a lawn, that you would like to use differently.
I gather materials for sheet composting throughout the year so that by fall I have a big pile of clean cardboard. I avoid the type of cardboard with slick sides because it takes longer to break down and contains clay. I also gather dried leaves, newsprint, decaying plants without seeds, some compost and aged chicken manure. In short, I use the same materials you would use in a compost or worm bin.
If you plan to sheet compost in an area that has never been dug, then turn the soil to a depth of two feet. This process aerates the soil so air and water will move through it more easily. If you are sheet composting in a grassy area, then loosen and turn the sod over so it will die. You will build your pile on top.
If I have old vegetable plants still in the beds, I cut them up and leave them in place. I may also put some kitchen waste on top of that. Then I build alternating layers, as if making lasagne. You can use whatever organic materials you have. I usually use cardboard, leaves and newsprint (laying them out in sheets – no need to cut up) or shredded paper. Then I repeat the layers. I top off the pile with aged compost and chicken manure. If my garden plot has diminished in height during the growing season, I may add more clean soil or compost when I construct the layers. I moisten each layer, then wet everything again. Then I cover with a plastic tarp, making sure it is secured on the sides so it does not go flying in the wind.
Watering each level is important because it encourages the microbes and other creatures to wake up and go to work. The red wigglers used in worm composting will start to move in and munch on the foods they love. They especially like cardboard and will move inside the corrugation. They enjoy the glue that keeps the cardboard together, and I often find that the cardboard layer disappears first.
Depending on the rain, you may not have to water the pile during the winter. However, it is a good idea to check the pile from time to time and water again if necessary to keep the layers moist.
In late April or early May, remove the plastic and see what has happened to your compost pile. It should be full of red wigglers and other creatures, and you may see some little white bugs hopping around. These creatures worked the pile for you, so you don’t have to do spring digging. As they worked through the compost, they turned the soil for you.
Sometimes the cardboard or other items are not completely decomposed by spring. I plant in the bed anyway by cutting holes in the cardboard where I want my plants to grow. On other occasions, I have covered the soil with cardboard and cut holes for my plants. This cardboard layer helps conserve soil moisture.
I once sheet-composted a bed in July and covered it with plastic. In late September I removed the plastic and found no trace of the materials I had layered just a few weeks before—only a bed of wonderful soil.
The droppings that the worms leave behind (known as worm castings) are beneficial to plants. They are a mild natural fertilizer containing all the trace elements. Some call these castings “worm gold.” It sells for about $600 a yard. When I plant in the spring, I do dig in some more chicken manure and worm compost from my worm bins.
Napa County Master Gardeners welcome the public to visit their demonstration garden at Connolly Ranch on Thursday mornings, from 10:30 a.m. until noon, except the last Thursday of the month. Connolly Ranch is at 3141 Browns Valley Road at Thompson Avenue in Napa. Enter on Thompson Avenue.
Master Gardeners are volunteers who help the University of California reach the gardening public with home gardening information. Napa County Master Gardeners ( http://ucanr.org/ucmgnapa/) are available to answer gardening questions in person or by phone, Monday, Wednesday and Friday, 9 a.m. to Noon, at the U. C. Cooperative Extension office, 1710 Soscol Avenue, Suite 4, Napa, 707-253-4143, or from outside City of Napa toll-free at 877-279-3065. Or e-mail your garden questions by following the guidelines on our web site. Click on Napa, then on Have Garden Questions? Find us on Facebook under UC Master Gardeners of Napa County.