- Author: Cynthia Nations
- Editor: Maggie Mah
Our northern California coastal climate allows us to grow vegetables all year round. In contrast to many parts of the country, where gardens and gardeners are in hibernation, fall is also one of the best times to start winter planting and get a head start on spring planting. Many local nurseries offer seedlings and, as many people discovered during the pandemic, germinating your own plants from seeds is rewarding, inexpensive and fun. What's more, there is a dizzying variety of seeds to choose from. Now, many modern day seed aficionados are using a technique known as “soil blocking,” a simple and effective method of starting seeds that was used by the Aztecs more than 2000 years ago.
Although the Aztecs used cubes of nutrient-rich mud to grow their seedlings, modern day soil blocks are composed of potting soil and other ingredients that are compressed into cubes of various sizes. The cube functions as both the container and the soil for starting and growing seedlings, eliminating the need for plastic cell packs or peat pots. Seedlings develop a stronger root system because more oxygen is available to the roots when the growing medium is not surrounded by a barrier, as it would be in a pot. Once the roots reach the edge of the block, they are “air-pruned,” a natural process that temporarily slows down root growth. This not only prevents a plant from becoming root bound but, once it is transplanted, allows it to become established more quickly because there is less disruption to the roots and therefore, less potential for transplant shock. A final advantage to soil blocks (and something to which every gardener who has mangled a plant getting it out of a pot can relate) is that when seedlings are ready, all you need to do is dig a hole and plant--far less stressful for all concerned!
Soil Blocking: What you'll need:
Different combinations of ingredients can be used as long as the mixture holds together when mixed with water. Here are two options:
Option 1: 1 part peat moss or coco coir + 1 part pearlite or vermiculite + 1 part compost.
Option 2: 1 ½ *bucket peat moss or coco coir, ¼ C. garden lime, 1 bucket perlite, 1 C. all-purpose organic granular fertilizer, ½ bucket garden soil+ 1 bucket finished compost
*2.5 gallon bucket
--A large container to hold your potting mix
--Warm water (tap is OK)
-- Soil Blocker tool: spring-loaded device that compresses the soil mixture into blocks and forms an indentation on top to plant the seed. The best size tool for most seeds makes 4-2” X 2” X 2” cubes at a time. --Garden seeding tray lined with cardboard or paper
--Labeling tape, spoon, tweezers
The following steps are for a 2-inch soil blocker that produces four soil blocks at once.
How to make soil blocks:
- Combine the pre-made mix or your own mix with water, and store until you are ready to use.
- Line your container with cardboard or paper; you will be watering from the bottom, and this will help absorb the water.
- When you are ready to make your soil blocks, scoop out the soil mix into a container. Add water and mix; the soil should have the consistency of peanut butter. You can also add water and let it sit for a while to increase absorption.
- To make the blocks, pile the soil mix into a mound that is about double the height of the soil blocker. Then plunge the soil block maker into the mixture. Twisting as you plunge helps compress the soil.
Ensure the cubes are compressed and filled tightly.
- Scrape off the bottom of the soil block maker with a straight edge and set the blocker in your seedling tray. Release the soil blocks by pushing down on the handle and lifting the blocker. The blocks should be firm. If the blocks crumble, add more water to the mix. If they slide out easily and fail to hold their shape, add more dry mix.
- Plant your seeds directly in the depressions created by the soil blocker. Label the soil blocks using tape on the outside of the tray. We a soup spoon and tweezers to facilitate this step. Ensure you follow the directions on the seed packet. Some seeds do well if you soak them before planting.
- Water the blocks from the bottom up or mist. Do not water from the top; it will erode the block.
- After seeding, the seeds are covered with a bit of peat moss. This step helps germination. Ensure you follow the directions for seed depth.
- Soil blocks are easy to move around and organize. If a block fails to germinate, you can remove it from the tray. It is easy to know when it's time to transplant the seedling or pot up into larger containers because you will see the roots when they reach the edge of the block.
Seed germination is a great way to experiment and learn more about gardening. As you learn and refine your materials and techniques, you'll find that soil blocking leads to healthy transplants and a thriving garden. For more information, check out the following resources: Seed blocking: The New Organic Grower (1995), Eliot Coleman.
YouTube Seed Blocking: https://www.youtube.com/watch?v=xLbAkqau_MI
Cynthia Nations is a San Mateo/San Francisco UC Master Gardener who recently purchased a soil blocker and is currently germinating broccoli, spinach, and lettuce seedlings. This article was edited by Maggie Mah, a SM/SF UC Master Gardener.
- Author: Jamie Chan
- Editor: Cynthia Nations
- Editor: Maggie Mah
With Halloween just around the corner, it's a good time to think about doing something a little different with your garden. How about adding drama and seasonal color with dark and mysterious plants? Here are five fascinating varieties that look exotic and also do well in our cooler coastal climate. They are sure to spark curiosity and conversation!
A Note about USDA Hardiness Zones:
All of the plants listed below have alphanumeric designations which correspond to the USDA Hardiness Zones. Each zone represents the average minimum temperature and the suitability of plants for a particular area. The lower the number, the colder the area is likely to be. Coastal areas of Northern and Central California fall into 2 zones: 9b (slightly inland) is hardy to 25-30°F and 10a (closest to the coast) is hardy to 30-35°F.
The Black Bat Flower (Tacca chantrieri)
This bizarre yet beautiful member of the yam family has wing-shaped bracts (specialized leaves) and seed pods that resemble bat faces. As an understory plant native to the forests of Asia and Australia, this unusual plant prefers mostly shade and moist, well-drained soil. It grows best in semi-tropical environments (USDA Zones 9b-11.) Black Bat flowers do not last long after they are cut so forgo the vase and enjoy them as a dramatic feature in the garden. The plant will provide large, ample blossoms beginning in late spring and continuing through early fall.
Hellebore (Helleborus, several species)
Hellebores are evergreen members of the ranunculus family with thick, dramatic, pest resistant leaves. One of the earliest bloomers, their flowers range in color from soft pink to almost black. This herbaceous perennial is happy in a wide range of climates (USDA zones 3-9) and appreciates shade in summer and sun in winter so a spot near deciduous plants might be ideal. After blooming, the foliage remains attractive into the summer and make eye-catching mass plantings in summer shaded areas. Like many other common landscape plants, be aware that Helleborus niger and Helleborus orientalis are toxic. But this just adds to that spooky reputation - beautiful and deadly!
Witch Hazel (Hamamelis, spp. - several species)
Witch hazel is a small perennial tree or large shrub which produces yellow threadlike flowers in early spring or late fall. The leaves, bark and twigs contain polyphenols and essential oils which are extracted and used in various preparations to soothe irritated skin. The plant does well in cooler areas (USDA zones 3-9) and is hardy down to 0° F but prefers full to part sun. While this plant does not seem to attract witches of any kind, the branches were often used in the past as divining rods. One thing you can be sure of: it will be a fragrant showstopper in your fall and winter landscape.
Corpse flower or Voodoo flower (Amorphophallus, several species)
This member of the philodendron family gets its name from the large “spathe” or shroud-like flower that emits a putrid odor when it blooms to attract pollinating insects, including flies. Also called Devil's Tongue, Dragon's Plant and Snake Palm, these perennial tubers are native to subtropical areas of Asia and generally do best in partial shade in USDA zones 7-10. Although most are grown for their spectacular looks, the starchy tuber of one variety (A. konjac) is processed into a kind of flour and used to make noodles and fruit jellies. Many species can grow indoors as a houseplant and then brought outside during the summer months as a potted feature in the garden. Beware – you may clear a room when these spooky plants bloom!
Pitcher Plant (Sarracenia spp. - several species)
A native to North America that grows ideally in USDA zones 6–8, the carnivorous pitcher plant loves boggy, waterlogged locations and can easily be identified by their rosette of modified leaves which form “pitchers.” While dramatic to the human eye, the pitcher shape acts as a container which holds water, attracting insects which drown and are eventually digested by the plant. These spooky herbaceous perennials prefer full sun, slightly acid soil and consistently moist conditions. In spring, each mature purple pitcher plant produces a single 3-inch flower, which starts as a downward "nodding" head and eventually reveals yellowish, pollen-bearing stamens.
These are just a few examples of some of the “spooky” plants to explore. While you are deciding, leave space in the garden for garlic—its powers to ward off vampires are legendary.
More about USDA zones: https://planthardiness.ars.usda.gov
Images from Pixabay.com
Jamie Chan is a SM/SF UC Master Gardener and the current Director of Programs and Partnerships at The Gardens of Golden Gate Park. She is a native San Franciscan who loves to garden while tending chickens and honeybees in her foggy urban backyard. The article was edited by UC Master Gardeners Cynthia Nations and Maggie Mah.
- Author: Maggie Mah
- Editor: Cynthia Nations
“Hugelculture?” The name (pronounced “hoo-gull kul-toor”) sounds like it might be a
new type of yogurt or maybe an exotic fermented beverage but it's neither of those
things. “Hügel” is the German word for hill or mound and Hügelkultur (hugelculture in
English) is a term for a unique way of growing plants in rounded, above-ground beds.
The beds, which are created from layers of decomposing wood and other plant debris,
approximate the conditions found in healthy, self-sustaining ecosystems. First defined in
Germany in the 1960's, the practice has become increasingly popular in many parts of
the world driven by a growing interest in permaculture* and the need for finding
sustainable methods of agriculture. Hugel beds are easy and inexpensive to make and
have a lot of advantages for home gardeners. They are also fascinating and fun!
How Hugelcultures work
Each hugelculture mound essentially forms its own ecosystem with woody debris
forming the foundation of the biological process. Although building a hugelculture is like
making a compost pile, it's a lot less work. The wood, which can be anything from fallen
trees and large branches to old firewood, is covered with layers of additional organic
material. As the woody material on the bottom of the pile decays, it becomes
increasingly porous and soaks up water like a sponge. The decomposing wood forms a
cozy habitat for beneficial organisms, which go about their business converting all the
organic matter into a rich medium for growing plants.
The advantages of Hugelculture
It's not surprising that a method of above ground planting that utilizes odd pieces of
wood originated in cold, heavily forested Northern Europe. Planting could be
accomplished while the ground below was still frozen, and warmth generated by the
microbial action in the mounds enabled both earlier planting and a longer growing
season. So why would we, in temperate Northern California, be interested in these
funny looking mounds? First, unlike conventional raised beds, no carpentry skills or
special equipment are needed--anybody can do this. Second, hugels are very
inexpensive to build and utilize materials that would otherwise get carted away.
Hugels are space efficient, can be made in virtually any size or shape and, unlike the flat,
rectangular surface of the usual boxy raised beds, the hugel's mounded profile creates
more surface area for planting. Just like other raised beds, hugels are constructed so
that the center of the bed is accessible from the sides, making it easier to plant and
maintain. Due to the sponge-like nature of the decomposing wood, ample amounts of
nutrients and the naturally aerated growing medium, a well-made hugel bed requires
less water, especially on the lower portion. Once the mound is completed, a good
hugelculture will also require little in the way of additional soil amendments.
A few caveats and rules
Many of the same rules apply to building a hugelculture as to building a compost pile.
For example, manure from herbivores (horses, cattle, etc.) is a great addition but waste
from carnivorous animals (dogs, cats) should be avoided.
Almost any type of natural wood can be used except black walnut and black cherry,
which are allelopathic (meaning they contain naturally occurring substances that inhibit
the growth of other plants) and pressure treated wood, which contains chemicals that
resist rot and insects. Woods such as cedar and redwood break down more slowly so
they should be used sparingly.
Hugels will sink over time but depending on a variety of factors such as location,
materials, shape, size, etc., a well-made hugelculture will last anywhere from 5 to 10
years. When the old hugel needs replacing, the material can still be used as mulch or
further utilized in a compost pile. Hugelcultures are not suited for planting trees and
other long-lived woody perennials, which can be easily toppled in the wind and severely
disrupted when the mound needs to be redone. Instead, plant them adjacent to a
hugel where they can benefit from the moisture and nutrients.
Building Your Hugelculture
First, it's a good idea to let your neighbors know what you are up to because Hugels can
look a lot like burial mounds! Pick the spot: it should get plenty of sun and be protected
from the wind. Next, decide what size and shape you want your hugelculture to be. It
can be roughly rectangular, oval, round or even serpentine. The length doesn't matter
but the finished mound should be narrow enough so that you can easily reach the
center. Then mark out the perimeter and lay bricks, stones, or logs to contain the
mound.
branches, twigs, and wood chips. Then add alternating layers of green (nitrogen rich) and
brown (carbon rich)** materials similar to making compost. Top it off with at least
several inches each of compost and soil. Then water the mound thoroughly.
Fall is the best time to get started so that your hugelculture will be ready for spring
planting. Allowing the mound to sit for a few months will ensure that the materials are
decomposed sufficiently and will not pull nitrogen from your plants. If you've used mostly
When ready, use the top areas for upright crops and the sloping sides for plants that like
to sprawl like strawberries and squash. Finish it all off by covering the surface with
plenty of mulch. Once this natural process is set in motion, you can sit back and enjoy
watching Mother Nature work her magic.
**For more on composting and green and brown materials, go to:
https://anrcatalog.ucanr.edu/pdf/8367.pdf
This article was written by Maggie Mah and edited by Cynthia Nations, San Mateo/San
Francisco University of CA Master Gardeners
- Author/Editor: Cynthia Nations
- Author/Editor: Maggie Mah
Growing more fruits and vegetables than your family can eat is a great gardening “problem” to have. What did you grow last year that you shared with others? You probably won't have to think very long, because sharing is powerful, makes everyone happy, and creates lasting memories. During the contemporary plague known as COVID, many of us turned to our gardens as a way to maintain our physical and emotional well-being. Now, as we (hopefully) return to some sort of normal, our gardens can help us reconnect to others in very meaningful ways.
Vegetable gardens reach their peak in late summer. Tomatoes ripen at a rapid pace, squash and beans can't be harvested fast enough and people in your household start rolling their eyes at your latest zucchini creations. Figuring out what to do with all that fresh produce can be a dilemma. Some may channel their pioneering (or hippie) forebears by drying, freezing, or canning. All of these methods of preservation are laudable, but frankly take more time, space, and know-how than most of us have. Rather than having your produce go to waste or ending up in the compost pile, share the abundance you created with friends, neighbors, and even your whole community. Although this might provoke images of going door to door with a wheelbarrow (or providing a really good rationale for acquiring a vintage pick-up truck!) you can donate your fresh produce to local food banks. On a larger scale, two organizations are partnering to create a sustainable system of providing high quality vegetables and fruits to people with limited resources.
Each Green Corner (EGC, https://www.eachgreencorner.org) is an all-volunteer group that works to bridge the gap between home gardeners and places where members of the community can obtain fresh, healthy produce, thereby strengthening the connection between food security and public health. Inspired by the fact that interest in non-commercial agriculture was increasing throughout the area, the all-volunteer group saw the potential to leverage smaller, underutilized plots of land scattered throughout the area (residences, schools, parks, etc.) to grow fresh food for the culturally diverse population in the greater community. EGC works with home gardeners (each person “hosting” a garden is referred to as a “Garden Steward”) educating them to grow produce using sustainable practices that can supply produce to food-insecure community members in San Mateo County. EGC-supported gardens are not limited to private residences, however. Any underutilized plot of land, such as out-of-the-way areas of schools, community properties and other public spaces are considered fair game for creating gardens. In combination, each small-scale effort becomes part of something far more significant in the effort to create and maintain a healthier world.
EGC was founded as an official 501(c)(3) not-for-profit organization in 2018 and since then has worked to educate and assist people to harvest excess produce from each garden and donate the surplus to local non-profit food distribution organizations. To date, EGC has donated over 6500 pounds of produce from 15 sites throughout San Mateo County. EGC was recently named one of San Mateo County's Sustainability Heroes of 2022 (See https://sustainablesanmateo.org/). Each year, Sustainable San Mateo County (SSMC) recognizes the efforts of local organizations that make significant contributions in protecting the planet.
The University of California Master Gardeners Harvest for Neighbors project (H4N - https://smsf- mastergardeners.ucanr.edu/projects/harvest-for-neighbors/) aims to reduce food waste by ensuring all fruits and vegetables grown locally get used, to introduce more people to gardening, and to promote best practices of sustainable gardening. With the missions of H4N and Each Green Corner so closely aligned, it seemed only natural that they should work together. The two organizations have recently formed a partnership wherein UC Master Gardeners provide research, education, experience, and expertise to EGC “Garden Stewards” to assist them in developing and maintaining their gardens.
Bottom line: working together in gardens and donating fresh produce to food pantries in the Bay Area fosters a win-win scenario for all. Growers who are passionate about working in the garden can feel confident knowing that their skills have made a difference as their produce is shared.
If you like the idea of working with others to promote better nutrition and quality of life in your community but can't go all-in, there are great options to consider. One is to grow an extra row of whatever fruit or vegetable you might have in your garden. Another might be to volunteer at one of the Each Green Corner locations. More information can be found in the links provided above. The websites listed also contain information about food pantries that welcome home-grown food in the Bay Area.
The article was written and edited by UC Master Gardeners Cynthia Nations and Maggie Mah.
- Author: Maggie Mah
- Editor: Cynthia Nations
- Editor: Terry Lyngso
- Editor: Kelly Torikai
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We're learning a lot about micro-climates and how small variations in temperature, humidity, wind, and other factors determine what grows best in a particular location. There's not much one can do about any of those factors, but there is something you can do that will have a positive impact, no matter where you live or what might be going on in Earth's biosphere: you can improve any garden anywhere by improving the soil. It's easy to do, the results are dramatic, and the benefits extend beyond your garden.
Sand, Silt and Clay: Texture is here to stay
The soil beneath your feet has a basic nature according to the geological history of your location and the type of “parent material” (rocks) from which it was formed. “Soil texture” is defined according to the percentages of sand, silt, and clay. This is good to know because different soil textures have different properties and will affect things like water filtration and nutrient availability. Soil texture does not include organic matter. Here's where things get interesting: you cannot change soil texture, but you can make major changes to how it functions by adding organic matter.
Imagine a pile of rocks, a bucket of sand or a lump of clay as various types of soil texture. Now imagine trying to grow something in any of them. Without organic matter, it's not going to happen. So, what is organic matter? Simply put, organic matter is anything that is alive, or was once alive: plants, animals, insects, microbes are all broken down by the microbial community. Organic matter improves the capacity of soil to infiltrate and hold onto water and nutrients, and this makes it possible for plants to grow and thrive.
Healthy Soil: It's like a good party
Soil with plenty of organic matter teems with life. Like a good party, there are lots of interesting guests (microbes such as bacteria and fungi. Also insects, etc.), plenty of good food and drink (available nutrients and water), enough room to move (loose, non-compacted soil), and plenty of action. Viewed through a powerful microscope, a handful of healthy soil would reveal billions of organisms doing their job. Although organic matter may only make up 5% of your soil, it is the 10% of microbial life in the organic matter that is essential for all soil functions like water infiltration, nutrient cycling, carbon sequestration and plant health.
At the other end of the spectrum is unhealthy soil. Like a ghost town, the microbial residents have vanished, and the place is dusty. It cannot infiltrate and retain water effectively and is easily eroded. This sad state can be caused by several things including no plant or mulch cover, repeated tilling, compaction, excessive use of chemical fertilizers, pesticides and herbicides.
How can I be sure my soil is healthy?
Effective use of organic materials such as compost can provide steady supplies of nutrients. This will create and maintain a desirable environment for the beneficial microorganisms that are essential for healthy soil. Did you know that leaving lawn clippings in place and allowing fallen leaves to remain is an effortless way to improve your soil? These are organic materials that break down quickly.
Keep it covered: Keeping soil covered with plants, leaves and organic mulch moderates soil temperature, conserves moisture, and prevents erosion while adding habitat and providing food for beneficial organisms. Remember all mulch eventually breaks down, so more needs to be applied either from leaves dropped by plants or from mulch applied by you.
Do not disturb: Avoid tilling or turning the soil. Instead, add a thin 3⁄8” layer of compost with a 2-3” layer of mulch on top and let nature do the work of aerating and opening things up. Be careful with leaf blowers by limiting their use to hardscape areas. This helps preserve valuable organic matter and topsoil and the beneficial microbes that live there.
Beyond the Garden Wall: Healthy soil has global implications
Carbon capture: Unlike carbon in the atmosphere, carbon stored in the soil is a good thing. Through a process known as “carbon sequestration,” soils can retain carbon in the form of organic matter, some of which is stable and some of which cycles. It is important to remember that plants and soil life are responsible for development of the organic matter that is held in soils. Recent studies show that soils alone trap about 25 percent of the world's annual fossil fuel emissions. So, if we want to sequester more carbon in the soil, we need more plants growing in a microbial diverse community.
Pesticide reduction: Just as healthy humans can more easily fight off diseases, plants grown in healthy soil are more naturally resistant to diseases. That means less reliance on pesticides.
Water efficiency: Healthy soil acts like a sponge: it holds onto water, so water is available to plants over an extended period. Good news for our climate with only winter rainfall. According to the USDA, every 1% increase in organic matter increases the soil's water holding capacity by as much as 25,000 gallons per acre. When water is stored in the ground, it also recharges groundwater. Healthy soil improves water quality by filtering out pollutants.
For more information on improving your soil, go to: https://marinmg.ucanr.edu/BASICS/SOIL_813/
For more help with your garden, ask a Master Gardener! Send your questions to mailto:mgsmsf@ucanr.edu
This article was written by Maggie Mah (who is surprised to be so excited about compost) and edited by Cynthia Nations, Terry Lyngso, Kelly Torikai, Nancy Kruberg, and Nick Landolfi, SM/SF UC Master Gardeners.