Got a gardening question? We have answers!

Garden Resource Days are a great time for gardeners, from the very beginner to the seasoned expert, to ask questions of our University of California Cooperative Extension Master Gardener volunteers and the Urban Agriculture/Community Gardens Program staff. For the next few editions of The ComPost, we will address the most frequently asked questions If you have a question you would like us to answer, please write to us at [email protected] or come out to one of our Garden Resource Days to ask in person.

Spring 2023 Garden Resource Days will be held on February 25, April 1, and May 6. All events are 10 a.m. to 1 p.m., at the overflow parking lot for Gleneagles Golf Course, 2100 Sunnydale Avenue.

Q. For beginning gardeners, or even experienced gardeners who have recently relocated to San Francisco, a common question is "What can I plant at this time of year? And should I start with seed or seedlings? What is easiest? Will seeds germinate in winter temperatures?"

A. Our temperate Bay Area climate allows for many successful year-round crops. But how do you know what to grow and when? First, decide what you want to eat. Then, take a look at the growing calendars developed by the San Mateo/San Francisco County Master Gardener Volunteers from the University of California Cooperative Extension. Determine if your garden is in a hot, sunny, or foggy climate area, select the appropriate calendar, and review what can be grown in the current month. To identify the best variety of the plants you want for your garden, look at Pam Peirce's Golden Gate Gardening: The Complete Guide to Year-Round Food Gardening in the San Francisco Bay Area and Coastal California, one of our favorite gardening books. Peirce lists many different varieties of each plant that can be grown successfully in this area and includes sources for seed purchases.

The growing calendars indicate when seeds and/or transplants can be used. Which is better? There are advantages and disadvantages to both and some plants prefer one method over another. Artichokes, asparagus, beans, celery and brussels sprouts all do best with transplants. Corn, kale, peas, potatoes and most root crops are better off with direct sowing in the ground. (A more extensive list can be found here, see column four, but note the planting times will be different for SF.) Starting with seeds can be less expensive and provide a greater assortment, including new, rare or unusual varieties. Local seed libraries allow gardeners to share seeds from their favorite plants too, ensuring a variety that has been successful in your area. For tips on what plants to grow for seed saving, how to collect and store: seed saving basics 

However, seeds that are sown in advance of their ideal outdoor growing time, may need to be started indoors or in a greenhouse. Seed starting medium must be purchased or mixed yourself, and containers/pots are needed, although recycled egg cartons, yogurt containers or even paper pots can be used as less expensive alternatives to seeding trays and plastic 6-packs. A link below provides info on soil blocking—a method that compacts soil into blocks so containers aren't needed. Direct sowing into the soil requires frequent watering and monitoring to ensure the top of the soil where the seeds are resting stays damp enough to soften the seed coat and germination to begin. 

Transplants make an instant garden—plant, water, and grow! You can select as many plants as you need, don’t need to over seed and hope that you will get the number of plants desired, and you won't have more plants than you can use. Usually, the starts you find in the nursery are appropriate for the current season, although they might not always be suited for your particular microclimate. Transplants are usually healthy and strong, have substantial root systems, have already hardened off, and are ready to go in the soil immediately.  A little plant food to give them a boost won’t hurt. However, you are limited to the varieties you can find in your local nursery or hardware store, may not be able to find organic options, and plant starts can cost upwards of $6.00 for a six-pack; more for four inch pots.    

Whichever method you choose, plan ahead. Decide what you want to eat from your garden, select the varieties that will do well in your area, and then determine if seeds or transplants will work best for you.

To learn more about starting seeds:  

• Planting vegetable seeds
• Seeding demystified     

To learn more about soil blocking:

• Soil blocking

To learn more about transplanting seedlings:

• Transplanting vegetables

To pick up seeds for free, visit RPD's Seed Lending Library at our Garden Resource Day events:

• Sign up to hear about those events through joining our listserv by emailing [email protected] and check the calendar in this newsletter.

Garden Spotlight: Koshland Park

Not even fading daylight can stop the BEETs from planting into the new year. The participants in this program for high school aged youth, run by CommunityGrows, installed a new native pollinator garden at Koshland Park Community Garden in early December, 2022.

Thank you to the Recreation and Parks Department's Nursery team for providing these beautiful plants!

Koshland Park Community Garden has about 60 plots, half of which are dedicated to youth educational programming facilitated by CommunityGrows, an environmental education organization dedicated to cultivating healthy youth through growing gardens in low-income, diverse communities. Community driven activism beginning in the early 70’s led to the creation of the Koshland Learning Garden and Community Park, the Western Addition Peace Wall, the Buchanan Street Mall, and the renovation of several other parks and community spaces in the neighborhood. CommunityGrows volunteers began teaching weekly gardening classes at Koshland, and as people’s interest (and plants!) grew, the classes began to happen more frequently. The BEETs Program (the Band of Environmentally Educated and Employable Teens) is one of three current programs that emerged from that early work. BEETs provides paid internships and hands-on learning experiences for high school aged teens to gain job skills through learning about environmental justice and gardening with a small group of their peers. In December, Rec and Park Community Gardens Program staff worked with the BEETs teens to create a native pollinator garden in an effort to improve safety in the garden and provide additional educational opportunities for teaching youth about the relationship between plants and their pollinator friends. Learn more about CommunityGrows and how they are creating future environmental stewards.

Around here, winter is the perfect time to add fruit trees to your garden or yard. Bare root trees are less expensive than potted trees and getting them started in the winter ensures their root systems will be established before the growing season.  Here are a few tips for successful planting that will create a healthy and productive tree.

1. Choose well. As always, your first consideration should be what kind of fruit you want to eat. Then, determine if that will grow well in your area. Some fruits need a specific number of chill hours - hours where the temperature is between 32 and 45 degrees Fahrenheit. Too little winter chill and not enough summer heat prevents proper fruit development in many varieties. Low chill (less than 400 hours) and early ripening varieties are best suited for San Francisco. This includes apples, plums, figs, pears, loquats, and citrus. This UCCE publication provides information about chill hours, pollination needs, and harvest times for many varieties well suited for Bay Area gardens: Selecting Fruit Trees for the Bay Area
2. Got sun? Your fruit tree will need six - eight hours of full sun to be productive. Find the sweet spot in your garden/yard that will provide the most sunlight. Avoid planting in a lawn as the watering needs are very different. Full size trees are happiest when they're planted 10 to 15 feet apart. Dwarf and semi-dwarf fruit trees are best of urban gardens with limited space. Smaller trees are also easier to harvest. To minimize access to your tree by rats and squirrels, and to make it easier to prune and harvest, don't plant too close to a fence or other structure - make sure you can walk all the way around your tree when it reaches its mature size.
3. Check your roots. Bare-root trees should be stored "heeled in" or covered with mulch, soil, sand, or damp leaves to keep the roots from drying out. Ask the nursery to pull them out for you to examine. Take a good look at the roots of your tree before you buy. A healthy tree has lots of root branches and hairs. Once you get the tree home, plant as soon as possible or cover the roots again, but get them in the ground within a couple days.
4. Plant up - don't dig. Prepare the planting area by loosening the soil but don't dig a hole. Trim any broken root branches with clean, sterile shears. Position your tree with the graft facing north. Spread out the roots at ground level and mound the soil to cover the roots; add compost to build the mound one to two feet tall. Top with mulch. Leave the graph point exposed. See the diagram above.
5. To keep the tree small, so you can reach the fruit when the tree is fully grown, you may need to adjust the size or growth pattern now. Make a first cut to the center most or tallest branch about 18 to 24 inches from the ground to force the tree to develop low branches. This is the only heading cut you will need to make.
6. Cover crop. Plant a cover crop (fava, clover) around your tree to improve soil fertility and texture. Plant so that there is 24" of space between the tree roots and the cover crop to ensure the tree roots receive adequate water. These annual plants can attract pollinators and, if correctly used, can even divert pests. As the cover crop matures, but before fruiting appears (such as fava beans appear) cut at the soil line, leaving the roots in the soil. Add mulch to the area, leaving 24" of space between the base of the tree and the mulch, to prevent root rot.
7. In areas with high levels of direct sunlight and heat, you may need to apply sunscreen to your tree trunk, which prevents bark damage that can cause tree failure. Though this is historically not generally required in San Francisco, climate change is increasing the number of hot and sunny days we experience, making this issue something we need to start monitoring. If you see deep cracks and peeling in your bark, you may need to protect through applying special. If you see damage in the bark, check with the San Francisco Master Gardeners to see if you need this.
8. While you wait for your tree to grow, dream about all the pie and preserves you'll enjoy!

Community Gardens are for the Birds: Stanford Bird Study

by Kelley Langhans

Anna’s Hummingbird at Michelangelo Community Garden (Photo by Maya Xu)

Stellar’s Jay at White Crane Springs Community Garden (Photo by Maya Xu)

Lesser Goldfinch at a community garden (Photo by Maya Xu)

We are a team of Stanford researchers studying birds in community gardens in San Francisco and how people feel about them. We began this project because we are really interested in two things: how to conserve birds and how to increase access to nature in cities. Urban farms and gardens are thought to be win-win spaces that are both good for animals and allow people to connect with nature in a meaningful way. We want to investigate this more:

• Do lots of bird species live in urban gardens?
• Do people value interacting with nature and birds in gardens?
• What features of gardens attract birds, especially the species that people care about?

These are all questions we are trying to answer through this research!



Our project is centered on 20 community gardens and farms spread out across San Francisco. It has two parts: counting birds, and surveying gardeners. Between July and September 2022, we visited each garden six times and counted all the birds we heard and saw in and around the garden. We also took notes about the plants we saw and other physical features of the space. Between October and December, we returned to our 20 sites and invited gardeners to take a survey about how they felt about nature, birds, and specific bird species in gardens.

We just finished data collection and are about to begin on detailed data analysis, but we can share preliminary results. In total, we observed 56 different bird species in and around the gardens this summer. Each garden had at least 10 different species, and some had more than 30. Some of the most common bird species that we saw were Anna’s Hummingbirds, House Finches, Lesser Goldfinches, California Scrub Jays, and Black Phoebes. We were able to survey over 150 gardeners—thank you so much to everyone who welcomed us to their gardens and took the survey! We are looking forward to looking at the survey results in more detail, and exploring how the bird communities at each garden are affected by what is growing there. We hope to share more soon!

Upcoming Events

Workshops

January

FREE Urban Composting Workshop Learn how to make your very own compost! The backbone of every healthy garden, compost improves all soil types and can be a difference between success and failure with many plants. In this FREE workshop, we will teach you how to make compost in your backyard, and introduce you to our worms that make their own special fertilizer. We will also give you tips on using your city compost bin. Come learn what you can do to improve your garden and prevent organic waste from ending up in the landfill! FREE.

When: Saturday, January 7, 10 a.m. - noon

Where: Garden for the Environment,1590 7th Avenue

Registration: FREE Compost Class

Quarterly Plants and Seed Exchange Bring a plant, take a plant, share cuttings, starts, bulbs, full-sized plants, or seed with your fellow gardeners. All types of plants are welcome: succulents, house plants, flowers, herbs, etc. Please label your plants so we know what they are. FREE.

When: Sunday, January 8 , 2 - 4 p.m.

Where: Mission Bay Branch Library Program Room, 960 4th Street

Registration: Mission Bay Public Library

Grow Your Own Food in January In this workshop, you'll learn how to get your garden in shape for 2023 by exploring soil fertility, weed management, and cool-season crops. $25 - $50

When: Saturday, January 14, 10 a.m. - noon

Where: Garden for the Environment, 1590 7th Avenue

Registration: Grow Your Own

School Garden Leaders Workshop School Garden Leaders are invited to attend our winter Zoom workshop to learn and share ideas. Topics to be covered include: Garden Connections for Spring Holidays - how plants are used in cultural celebrations; and School Gardens Beyond Vegetables – what else you can grow and use to enhance your curriculum.

When: Saturday, January 21, 10 - 11:30 a.m.

Where: via ZOOM

Registration: School Garden Leaders

Winter Fruit Tree Pruning Learn how to maximize tree health and fruit production by identifying and properly removing dead, damaged, and dying wood. Our expert instructors will go over general pruning techniques, discuss the differences between summer and winter pruning, and lead a hands-on demonstration so that you can learn which cuts to make in the winter to keep your trees healthy and productive. $25 - $50

When: Saturday, January 28, 10 a.m. - noon.

Where: Garden for the Environment, 1590 7th Avenue

Registration: Winter Fruit Tree Pruning

Geraniums and Pelargoniums of the World Learn about pelargonium varieties suitable for container or indoor growing and expand your collection with rare varieties. Use scented geraniums to develop a sensory experience and grow your tiny scented garden in your apartment. FREE.

When: Sunday, January 29, 2 - 3 p.m.

Where: Mission Bay Branch Library Program Room, 960 4th Street

Registration: geraniums-and-pelargoniums-world

February

FREE Urban Composting Workshop Learn how to make your very own compost! The backbone of every healthy garden, compost improves all soil types and can be a difference between success and failure with many plants. In this FREE workshop, we will teach you how to make compost in your backyard, and introduce you to our worms that make their own special fertilizer. We will also give you tips on using your city compost bin. Come learn what you can do to improve your garden and prevent organic waste from ending up in the landfill! FREE.

When: Saturday, February 4, 10 a.m. - noon

Where: Garden for the Environment, 1590 7th Avenue

Registration: FREE Compost Class

House Plants The UCCE Master Gardeners of San Mateo and San Francisco Counties present this "Houseplant Basics" course to help you decide which plants to purchase and how to best take care of them. FREE.

When: Sunday, February 5, 2 - 3:30 p.m.

Where: Mission Bay Branch Library Program Room, 960 4th Street

Registration: Mission Bay Public Library

How to Create Stunning Container Gardens Whether you have a small garden, balcony, deck or a simple window box you can bring pops of color to your outdoor space by creating lush container gardens. Arete Nicholas, Master Gardener, will discuss design, color, plant placement and how to choose the right plants as keys to creating stunning containers overflowing with flowers, herbs and trailing plants. You will also learn how to care for your containers and refresh them as the seasons change.

When: Saturday, February 11, 1 - 2:30 p.m.

Where: San Francisco Public LIbrary, Richmond Branch, 351 9th Avenue

Registration: not required. For more info: Container Gardens

Growing Orchids - Tips for the SF Bay Area Climate Learn about cool, temperate and tropical zone orchids. Which type is good for you? Get to know cool growing orchids for San Francisco and the Coast such as Masdevallia and Cymbidiums as well as everyone’s favorite indoor orchid - the Phaelaenopsis. Discover how to successfully re-pot your orchid, water, feed and get them to re-bloom, along with methods for dealing with common pests and diseases.

When: Saturday, February 11, 11 a.m. - 12:30 p.m.

Where: San Francisco Public Library, Sunset Branch, 1305 18th Avenue

Registration: not required. For more info: Orchid Tips Workshop

Super-duper Microgreens Oliver Gallo, owner of Super-Duper Microgreens, will talk about Community Based Agriculture and benefits of microgreens. Learn how to grow your own microgreens at home after you sample the varieties of microgreens at the workshop. FREE.

When: Sunday, February 12, 2 - 3:00 p.m.

Where: Mission Bay Branch Library Program Room, 960 4th Street

Registration: Mission Bay Public Library

March

FREE Urban Composting Workshop Learn how to make your very own compost! The backbone of every healthy garden, compost improves all soil types and can be a difference between success and failure with many plants. In this FREE workshop, we will teach you how to make compost in your backyard, and introduce you to our worms that make their own special fertilizer. We will also give you tips on using your city compost bin. Come learn what you can do to improve your garden and prevent organic waste from ending up in the landfill! FREE.

When: Saturday, March 4, 10 a.m. - noon

Where: Garden for the Environment, 1590 7th Avenue

Registration: FREE Compost Class

Succulents in Pots and in the Garden It's time to create a gorgeous container garden that will carry you through summer, fall and early winter. You will learn how to use the filler, spiller, thriller method of container planting. This workshop, presented by UCCE Master Gardener, Arete Nicholas, is geared toward all levels of gardener - from the very beginner to the experienced. FREE.

When: Sunday, March 12, 2 - 3:30 p.m.

Where: Mission Bay Branch Library Program Room, 960 4th Street

Registration: Mission Bay Public Library

Dig In! 2023: Six-Park Edible Gardening Series Learn the fundamentals of successfully growing food in your backyard in this engaging series taught by local gardening experts! $170 - $300

When: Saturday, March 25, April 1, April 8, April 15, April 22 and April 29, 10 a.m. - noon

Where: Garden for the Environment, 1590 7th Avenue

Registration: Dig In! 2023

Quarterly Plants and Seed Exchange Bring a plant, take a plant, share cuttings, starts, bulbs, full-sized plants, or seed with your fellow gardeners. All types of plants are welcome: succulents, house plants, flowers, herbs, etc. Please label your plants so we know what they are. FREE.

When: Sunday, March 26, 2 - 3 p.m.

Where: Mission Bay Branch Library Program Room, 960 4th Street

Registration: Mission Bay Public Library

January

• Pull weeds brought on by recent rains now before they go to seed.
• Top dress tender plants with a mulch mix.
• Plant bare-root fruit trees, start artichokes, asparagus and rhubarb.
• Keep plants covered and well-watered to avoid frost damage. Well hydrated plants will stand up to the cold much better.
• Start planning your summer garden; make a crop plan and planting plan for your annuals. (view the Master Gardener's planting schedule for San Francisco here.)
• Prune citrus trees (once the crop has finished), overgrown perennials, roses and shrubs. To learn more about pruning techniques, email us to set up a workshop in your garden ([email protected]) and take a look at some of these resources:
• An Illustrated Guide to Basic Pruning
• Training and Pruning Fruit Trees in the Backyard Orchard
• The Big Picture: Pruning Techniques
• Best Time to Prune Shrubs

February

• Plant potatoes, garlic, and onions.
• Prune lavender now to promote better flower production this summer.
• Plant bare root fruit trees now - bare root fruit tress are less expensive than potted fruit trees and nurseries offer more bare root varieties to choose from. UC ANR has a helpful guide for planting and caring for young trees.
• If you plan on using tomato seeds (instead of buying tomato plant starts) sow them indoors now.

March

• Prepare beds for spring - turn soil and add at least 4 inches of compost. Compost will be available at our Garden Resource Day on February 25, April 1, and May 6 March 26, 2022 at the Gleneagle Golf Course Overflow parking lot (2100 Sunnydale Avenue) between 10 a.m and 1 p.m. Bring your own buckets!
• If you planted fava beans as a cover crop, cut the plants down at the soil line when half the blooms have opened - cover crops are removed before fruits, in this case the fava beans, are produced. This will give you the greatest return of nitrogen to your soil.
• If you have not been fertilizing throughout the growing season, fertilize your citrus trees this month. Fertilizers and soil amendments that meet organic production standards improve soil microbiology and overall soil health which, in turn, helps our plants be healthier and more resilient. Choose any organically labeled citrus fertilizer and apply at the label rate. Fertilizer should be top dressed (sprinkled) directly on the soil at the tree's drip line (edge of the canopy). After applying, water in and cover the soil with mulch again. Citrus tree leaves should be dark green. If your citrus trees have any yellow in their leaves, you are not fertilizing enough. (Note: This is for citrus trees planted in the ground. If your citrus trees are in pots, you will need to fertilize much more frequently.)
• Plant your vegetable starts, gladiolas, and dahlias (San Francisco's city flower!) outdoors.