- Author: Matt McMindes, Master Gardener
When we lived in St. Louis Missouri, pin oaks graced the yards of our neighborhoods. When they dropped their leaves in the fall, the raking began with families filling up paper sacks purchased in bulk from the box stores. The annual fall event was as important as Halloween. The more rows of sacks on the curb, the more efficient and conscientious you were about raking leaves. I was so thankful burning was not allowed.
However, I never filled any paper sacks ever. I thought it a waste of time and energy. Instead, I first waited for the leaves in my yard to be windblown around the neighborhood. “Who can control the wind?” I thought. What a great idea this was. Some of my neighbors must have had the same idea and their leaves would end up equally in my yard. After seeing all of the leaves had fallen and been blown or raked, I would run my lawnmower with a mulching blade, cutting the grass and disintegrating the leaves. With the first fall rains, the leaves disappeared and my lawn and oak trees looked great in the spring.
We encountered a much different situation when we moved back to California in 2016. We now have a fenced, partially xeriscape backyard, with islands of mature valley oaks surrounded by a sea of river rocks. There was
an adjacent lawn area separated by a sidewalk where the late fall and winter oak leaves could be blown or raked for mowing or collection. However, there were too many leaves and not enough lawn to absorb the mutinous gathering. Where was my “aha” moment now?
Collaborating with Master Gardeners and reviewing university studies on leaf mulching / compositing, my first “aha” moment arrived. The answers to whether you should mulch oak leaves into turf, compost the leaves, use leaves for landscape mulch, till leaves into your vegetable garden, simply let the leaf litter lie, or combinations thereof, were summed up in two words: “it depends.” For my situation, it made sense to mulch some leaves into the turf, collect some for landscape mulch, till some into the vegetable garden, and compost the remainder. I was happy to have choices.
Mother Nature has been recycling oak leaves back into soil nutrients for plant growth since the first oak tree. There are numerous University studies that help us to better understand this process. Soil organisms (bacteria, fungi, worms, and insects) utilize oak leaves as a food source and in particular, release nitrogen, phosphorous, and sulfur back into the soil. By design, the rate of leaf litter decomposition and release of nutrients back into the soil is relatively slow. This is partially due to the low nitrogen content of leaves which controls the rate of decomposition. If you are using shredded leaves for landscape mulch, this is a good thing, as you want mulch to remain in place to prevent weeds from germinating / growing, hold in moisture, and slowly release nutrients back into the soil. However, if you are mulching leaves into turf, tilling into the vegetable garden soil or composting, an accelerated rate of decomposition may be more desirable.
To increase decomposition rates, decomposers require more nitrogen, around 30:1, which translates into one pound of nitrogen to thirty pounds of lightly moist organic material. The 30:1 ratio is achieved by blending oak leaves with high nitrogen sources such as inorganic fertilizer, grass clippings, and manures. Additional environmental factors that will speed up decomposition rates include adequate aeration, moisture, particle size, and heat. The Soil and Fertilizer Management Chapter of the California Master Gardener Handbook, Second Edition, as well as The University of Missouri Extension “Making and Using Compost” provides information on how to optimize decomposition rates, C:N ratios of compostable organic and inorganic materials, how to set up a compost pile and trouble shooting.
When tilling oak leaf litter (low in nitrogen) into soil as an amendment, the decomposer population and activities increase. However, Instead of adding nitrogen to the soil, they incorporate the nitrogen into their own cellular tissues. In this process called “Immobilization”, microbes are competing with plants for nitrogen. Therefore, if incorporating leaf litter into the soil at time of planting, it is recommended to add inorganic nitrogen fertilizer to balance the C:N ratio to around 30:1. Immobilization only temporarily locks up nitrogen and when the microorganisms die after consuming their food source, the nitrogen contained in their cells is converted back to plant available nitrogen.
For More Information
ANRCatalog - California Master Gardener Handbook--2nd Ed - ANR Catalog (ucanr.edu)
Making and Using Compost, G6956 | MU Extension (missouri.edu)
Don't Bag It - Leaf Management Plan - Earth-Kind® Landscaping Earth-Kind® Landscaping (tamu.edu)
Mulch leaves into turf for a smart lawn - Gardening in Michigan (msu.edu)
Don't sweep your leaves to the curb! Mulch them back into your lawn or garden - MSU Extension
https://www.youtube.com/watch?v=os-EFAPLcP0
Recycling Autumn Leaves // Missouri Environment and Garden News Article // Integrated Pest Management, University of Missouri
Autumn Leaves: From Trash to Treasure // Missouri Environment and Garden News Article // Integrated Pest Management, University of Missouri
Autumn Leaves - Myth and Reality | Missouri Department of Conservation (mo.gov)
- Author: Morris Lacy
During the summer, the MG Herb Study group met monthly to discover and discuss the herb of the month. June's herb was Basil, July's was mint, and August's was lemon balm. All three are great additions for gardens and add unique flavors and aromas to chosen dishes.
Another herb worth mentioning here is the weed Common Purslane. This is an edible plant which can substitute for spinach or lettuce; raw in salads or sandwiches or cooked in soups or quiche. Purslane grows in parts of the world with a wide range of environments including gardens, sidewalk cracks, rocky gravel beds, and even harsh desert-like caliche soil. It tolerates extremes including drought and very salty or nutrient-deficient soil.
Purslane has a long history of use in traditional/alternative medicine and is very nutritional. A 100-gram (3.5 oz) portion contains):
- Vitamin A (from beta-carotene): 26% of the DV.
- Vitamin C: 35% of the DV.
- Magnesium: 17% of the DV.
- Manganese: 15% of the DV.
- Potassium: 14% of the DV.
- Iron: 11% of the DV.
- Calcium: 7% of the RDI.
- It also contains lesser amounts of vitamins B1, B2, B3, folate, copper, and phosphorus.
You get all these nutrients in only sixteen calories! This makes it one of the most nutrient-dense foods on the planet, calorie for calorie!
Allium is a genus of monocotyledonous flowering plants that includes hundreds of species, including the cultivated onion, garlic, scallion, shallot, leek, and chives. Allium is Latin for garlic. Allium is an herb.
Alum is not an herb! An alum is a type of chemical compound, usually a hydrated double sulfate salt of aluminium with the general formula XAl(SO?)?·12 H?O, with “X” being a cation such as potassium or ammonium. Aluminium and Aluminum are the same element!
For more information on the herb of the month, check out the Herb Society of America.
- Author: Robin Fuller
When the Robert J. Cabral Agricultural Center opened in August 2008, the southwestern corner of the landscape had been set aside for the Learning Landscape through the efforts of then-San Joaquin UCCE County Director, Mick Canevari (emeritus).
Professional landscape designers prepared plans for the Learning Landscape without consulting the SJMG's program coordinator Marcy Sousa, or the UC Horticultural Advisor Ashley Bassinger. Sousa and Bassinger were able to review and rework some of the plans via change orders before the garden's installation. They swapped out redwood trees for more climate-appropriate selections, changed paths to permeable concrete, and add crushed granite areas, in accordance with best water runoff mitigation principles and garden practices for our Mediterranean climate. It was too late in the process to swap out many of the plantings and it has taken years to replace large swaths of plantings and form it into its current state (for example, a large rosemary patch is now the Mediterranean fruit tree area).
Based on the survey results and research trips, Sousa and Bassinger began adding appropriate plantings. They incorporated native, pollinator, and Mediterranean plants and trees into the landscape, and carved out an area for the Arboretum All Stars.
In 2010, Karrie Reid (just retired), took over as UCCE Environmental Horticultural Advisor and brought vast local expertise and structure to the gardens. Reid held meetings to brainstorm how to make the gardens more in line with MG goals. The group formalized seven themed sections; an 8th section was designated in 2021. Throughout the redesign of the gardens, Reid insisted on plantings that were truly appropriate for each themed area, suitable for the region, and with the exception of edible plants, either low or moderate water-use according to the Water Use Classification of Landscape Species.
- Entry Garden
- Foliage Garden
- Arboretum All Stars
- Edibles Garden
- Pollinator Garden
- Mediterranean Garden
- California Natives
- Cutting Flowers Garden (designated in 2021)
Several MGs were instrumental in the creation of the newly formed theme gardens. The Foliage Garden was the brainchild of MGs Susan Price and Sharon McDonnell, and has remained under McDonnell's supervision since its inception. MGs Kathy Grant and Rosalee Osman proposed and created the Pollinator Garden.
Volunteers then began the heavy lifting of turning the generic landscape into the themed gardens. Excepting one Xylosma tree, all plants and trees were removed from the Foliage and Pollinator gardens and replanted with appropriate species. Decomposed granite pathways were added into those gardens to allow visitors access to the plantings, and to avoid soil compaction and trampling of plants.
Edible landscaping was an emerging theme at the time. MG Rich Mullenbach was instrumental in removing excessive plantings, including a thorny Hawthorne tree that was a maintenance issue. He regraded the area in the Edible Landscape that became a pathway, and built the retaining walls, and volunteered many hours in the gardens.
MG Steve Sanguinetti has and continues to provide his expertise in reworking, repairing, and maintaining the irrigation system. Reid converted the irrigation in the Mediterranean Garden and Reid and Sanguinetti used the conversion of irrigation in the California Native section as an educational demonstration for MGs and the public at an Open Garden Day. Over time, Sanguinetti and Reid converted irrigation in much of the garden from point-source to modern internal drip line.
Reid also brought management structure to the gardens. She created Team Leader positions for each garden section. Team Leaders are responsible for the planning, communication, recruiting volunteers, organizing workdays, monitoring irrigation, and overall maintenance of the plants and trees within their gardens. The Team Leaders are entrusted with researching species appropriate for their garden and working with their group of volunteers to maintain each area. Several areas—the pollinator, cutting flowers, and edibles gardens change often and are reflective of the team's styles and preferences.
In addition to creating a management structure for the gardens, Reid created maps and maintenance calendars for each section and worked with the County to create signage for the overall garden and individual garden sections.
Reid's contributions and direction of the gardens for the past 12 years has been enormous. When interviewed, she mentioned,“Developing the gardens has been an ever-evolving project only accomplished through the endless hours given by MGs to this endeavor. I am incredibly proud of all their hard work, because it has created an inspirational space used frequently by the building's employees, as well as visitors to the Ag Center on business, who stroll through, take a break, or have their lunch. Additionally, it has become a resource for local landscape professionals and home gardeners who use it for ideas for regionally appropriate gardens. The signage we developed means the gardens are educational, even when we aren't on site to teach. I recently had the long-time head of marketing for Green Acres Nurseries tell me he sends clients here all the time to see our garden because of the many examples of sustainable and inspirational plant selections. It is so rewarding to see the goals we set come to life and I know it will remain a vital asset to the region.”
Master Gardeners are educated by subject matter experts in a variety of fields, including pest management, composting, plant pathology and propagation, water usage, and other subjects based upon their geographic location. They are tasked with educating the public based upon research-based practices. The Learning Landscape is a tool for MGs to learn and utilize best practices for gardening, and is one vehicle used for educating the public.
The San Joaquin County Master Gardener's program is funded and supported by AB939 and through San Joaquin County Solid Waste Division.
- Author: Jody and Morris Lacy
Fall, aka Autumn, normally begins in earnest as nuts come off trees and pumpkins come off the vines. I know commercially grown pumpkins and gourds have been coming off the vines for over 6-8 weeks now and almonds seemed a little early as well. My “giant” pumpkin came off August 26th! What gives? What is the new normal for this season?
As we continue to see changes in our climate, it is comforting to know the general nature of growing hasn't really changed. You must provide an environment which is suitable for the plant and use IPM (Integrated Pest Management) to ensure your crop or landscape succeeds. Here are my favorite pests to look forward to this season.
Rain is a good thing! However, it can be both pesky and detrimental if the quantity is overwhelming to plants now accustomed to the reduced amount of water we have been providing. This is a good time to check your irrigation systems, making sure you aren't killing the plants with “kindness” in addition to the expected rains of the season. Be sure to pay attention to your plants and adjust flow as well as providing nutrients for the soil and modify the consistency
if you find it is not draining sufficiently.
My favorite weed of Fall is Common Purslane (Portulaca oleracea). It is found throughout California to about 4600 feet. These plants are edible (they have a sweet, yet acidlike flavor. An excellent crunchy salad plant, it is said to blend well with hotter-flavored salad herbs) with vitamins and nutrition but can choke out or overwhelm the best of low-growing landscape or just make the bare areas of your garden an unsightly mess. Don't bother spraying these weeds – just pull them and compost them in your bin. These weeds are like fish from the hatchery placed in a lake – put and take.
You guessed it – Rats! BTW, I finally caught the one marauding around as Robin Hood in my vegetable garden. In California, the most troublesome rats are two introduced species, the roof rat and the Norway rat. It's important to know which species of rat is present in order to choose effective control strategies. Learn more about managing rats, here.
- Author: Sue Davis
The autumn months are such an easy time to decorate the garden, a front porch, or inside the home with items found in most gardens and nurseries.
In October, start with a few mums transplanted from the garden into pots, pails, baskets, tubs, etc. (they can be planted back into the garden wen no longer needed for decorations) and massed together form a beautiful decoration. No mums in the garden? Nurseries often have a large variety in early October from which to select. A variety of colors make the best display.
Add pumpkins and/or gourds to the display raised on old garden chairs, overturned 5-gallon pots, a couple of pieces of wood, or just leave on the ground for added visual interest.
A few large leaves that have fallen and not yet been added to the compost pile will add to the decoration.
All of that works for both indoor and outdoor displays. However, the pumpkins will probably not last through December in the warmer indoor air.
Round out the display in October with a skeleton, bats, or a witch to celebrate Halloween. Trade those items for a scarecrow in November.
Once Thanksgiving has passed, changing the outside display is a simple matter of removing the scarecrow and mums and getting some spray paint, a little glitter if that sort of thing is appealing, solar twinkling lights, and evergreen leaves or a few branches from bushes that bear red berries (like pyracantha). Spray the pumpkins silver, gold, red, or green. If making the pumpkins into red or green “ornaments” for the display, also punch a bread tie through the bottom of a small paper cup to form a “hoop” and spray the cups silver to glue over the stem as the top of the ornament. Once the pumpkins dry, set them out with twinkling lights and foliage placed around them to highlight the display. Once the display is dismantled, the foliage can be added to a compost pile and the twinkling lights can be strung through citrus trees to keep them protected from freezing weather.