- Author: Maggie Mah
Growing your own plants from seed has a lot of advantages: more variety, less cost and getting a head start on the growing season are just a few. Practicality aside, it's just plain miraculous to grow plants from seeds. The process of putting hard, dry, seemingly lifeless bits into soil and seeing the transformation to a living plant is fun, fascinating, and forms an amazing connection to the natural world. Some seeds can be sown directly into the ground, but others benefit from a gentler, more controlled beginning and February is the perfect time to get started. If the rows of colorful seed packets are enticing but the idea of growing anything from seed seems daunting, fear not. If previous attempts have been disappointing, fear not. Here's what you need to know to get growing:
How Seeds Work
It can be as big as a coconut or as small as a speck of dust, but every seed is a plant waiting to happen. On the outside is a protective covering known as a “coat.” On the inside is the “germ,” a tiny embryonic plant with a root, stem and one or more leaves. Surrounding the germ is nutritive tissue or “endosperm,” which sustains the incipient plant.
When soil temperature is right and sufficient moisture is available, the seed coat allows water and air to infiltrate, and the germination process can begin.
A tiny stem stretches upward, the Cotyledons unfold, turn green and disappear once the plant develops true leaves.
What Seeds Need
Three things are needed for germination: the right temperature, abundant moisture and sufficient oxygen. Too much or too little of any one of these factors will not lead to success.
Choices, choices
Unlike commercially grown seedlings, which are usually available in only one or two varieties, growing from seed gives you a much wider selection of varieties and allows you to select plants for conditions in your location. When selecting tomatoes and other seasonal crops, pay close attention to “Days to Maturity,” the term for the number of days it will take to produce fully ripened or mature produce. Varieties with fewer days to maturity are best for cooler, foggier areas. Be sure to use seeds from a reputable supplier and check the expiration date before purchase.
Plan Ahead
Decide the number of plants you want to end up with when your seedlings are ready to transplant. Factor in that some seeds will fail to germinate and that some seedlings will not be sufficiently robust to “graduate” to the garden.
In general, seeds should be started 6-8 weeks before the date you want to transfer to the garden. Starting too early can easily lead to your seedlings becoming root-bound so if in doubt, wait a week or two. Please refer to UC Master Gardener Planting Calendar: https://smsf-mastergardeners.ucanr.edu/Edible_Gardening/
For ornamentals, pollinators and other non-edibles that can be started from seed indoors, refer to the seed packet for timing.
Seed Starting Basics
Soil
Use a blend specifically formulated for starting seeds. It should be light and uniform in texture, sterile and nutrient rich. Never use “native” garden soil and avoid regular potting soil. Make sure soil is evenly moist prior to seeding.
Containers
Just about any kind of container will work if it is clean and has drainage holes. “Clam shell” food containers, yogurt cups and other plastic packaging can be re-purposed along with nursery “six packs” and 4-inch pots. Wash, rinse and sterilize by spraying with a solution of 1 part chlorine bleach to 9 parts water and air dry before using. You can avoid containers altogether by using soil blocks. (See below for more information.)
Seeding
Fill your containers about 2/3 full of soil and follow seed packet directions for planting depth and spacing. Seeds that are started closer together will require “up-potting” and/or thinning at a later stage. Note: some plants, such as squash, don't like that kind of disruption and should stay in individual containers until transplanting time.
Watering
Moisture is essential for germination and watering is best done from the bottom to avoid dislodging newly planted seeds. Place seeded containers in a solid tray that will hold water. (Concrete and mortar mixing trays are ideal.) Add water to the bottom of the tray to a depth of approximately ½ inch. Seed containers should be checked frequently to make sure the soil is evenly moist but not wet or soggy. Adjust the amount of water added to the tray to maintain adequate moisture while avoiding standing water for more than a few hours. Clear plastic covers help to retain moisture as does a light topping of vermiculite.
Provide light and warmth
Find a spot with bright, indirect light such as a sunny window and where temperature is between 65 and 70 degrees during the daytime and 55-60 at night. If the perfect spot is not to be found, consider using grow lights and specially designed heating mats for plant propagation. Both are inexpensive and energy efficient.
Growing
Maintain proper moisture, light and warmth and in 6 to 21 days, seedlings will start to emerge. First to appear are the tiny green cotyledons that have burst forth from the seed. As soon as the true leaves appear, seedlings can be “up-potted” to larger containers.
“Hardening Off”
Young plants that have been grown indoors require gradual exposure to outdoor conditions. About two weeks before transplanting and when night time temperature has reached 50°, start the process by moving plants outside to a shaded location during the day and bringing them inside at night. After that, gradually increase the amount of sun exposure during the day and allow plants to remain outside at night.
Transplanting
When plants have been hardened off, it's time to plant! Prepare beds well ahead of time, then dig holes the size and depth of the seedling pot (deeper for tomatoes). Allow adequate spacing for the size of the mature plant. Invert the pot, allowing the seedling to pass through your fingers and gently grasp the root ball. Invert and set the plant into the hole. Gently tamp down, adding more soil if necessary. Water carefully and finish by adding a layer of mulch.
It's no wonder that seeds and the act of planting are the basis of so many sayings and inspirational words. Whatever seeds you decide to sow, you will be part of an amazing, eternal process of renewal.
Any questions? Contact the Master Gardener Helpline: http://smsf-mastergardeners.ucanr.edu/
For more on soil blocking: https://smsf-mastergardeners.ucanr.edu/?blogpost=55580&blogasset=125102
For more on soil preparation: https://mg.ucanr.edu/Gardening/Vegetable/Preparing/SoilImprovement/
Maggie Mah is a UC Master Gardener who is fascinated by seeds.
UC Master Gardeners of San Mateo-San Francisco County are volunteers who are trained under the auspices of the University of California to provide science-based information on plants, horticulture, soil and pest management at no charge to the public. For more information and to find out about classes and events in your area, visit our website where you can also sign up for our newsletter: http://smsf-mastergardeners.ucanr.edu/
- Author: Maggie Mah
Last winter's epic rainstorms have caused many of us to think about what we can do to mitigate the impact of heavy downpours on our communities. As it happens, the impervious surfaces that keep us dry and mud-free (our homes, patios, driveways, etc.) also keep water from seeping naturally into the ground. Instead, rainfall is typically managed by gutters and downspouts which collect surface water and funnel it into drains and culverts. Unfortunately, what comes along for the ride are a lot of pollutants: pesticide residue, heavy metals, bacteria, etc., all of which end up contaminating our waterways and potable water supplies. According to the US Environmental Protection Agency, rainwater runoff accounts for an estimated 70% of all water pollution. Now for the good news: there's a simple solution to keeping that water from going down the drain that will not only beautify your landscape but do great things for the environment, too. It's called a “rain garden.”
What is a Rain Garden?
Known more technically as “bio-retention cells,” rain gardens are landscaped areas designed to capture and retain runoff water where it can be slowly absorbed into the surrounding soil. In the process, the interaction of plants and soil microbes makes significant improvements in the quality of the water, reduces flooding and helps to recharge groundwater. A well-constructed and maintained rain garden can remove up to 90% of the pollutants present in rainwater runoff and can absorb significantly more water than conventional landscape areas such as lawns. Unlike natural areas that are slow to drain, the water in a properly designed and constructed rain garden will allow water to infiltrate in 48 hours or less, which means mosquitoes will not have enough to time to breed.
How Rain Gardens Work
The name may conjure up watery images of ponds and lily pads but “rain gardens” are dry most of the time and blend seamlessly into the existing landscape. During a rain event, runoff is directed to a location in the ground that has been excavated to be slightly shallower than the surrounding area, forming a basin to temporarily contain a quantity of water. In the “basin” are plant varieties that are strategically selected and placed to survive the extremes of periodic flooding and drought conditions. When water flows into the rain garden, it irrigates the plants while soil microbes go about the job of breaking down pollutants and providing nutrients for the plant roots to absorb. As the plants grow, they provide an attractive habitat for birds, butterflies, and other animals.
Size Matters
How big should a rain garden be? Ideally, it should be large enough to capture and contain the water that comes off the roof of your home, patio or other paved area. During a storm that dumps an inch of rain, about 200 gallons of water will be shed from a 400 square foot roof. This would require a rain garden approximately 20% of the size of the roof or about 50 square feet. Size calculations will vary according to soil types and other factors but even a small rain garden can make a big difference.
Site Selection
The location of your rain garden should be at least 10 feet away from structures and in an area where water from downspouts or drains can be directed. This can be in a natural depression, flat area or gentle slope no greater than 12%. Ideally, the location should receive full sun to partial shade for plants to do their best and soil must be able to percolate water at the rate of approximately ½ inch per hour. Depending on the terrain, the long side of a shape should be arranged perpendicular to a slope to catch as much water as possible. Areas with heavy clay soils, trees and tree roots, utilities, septic tanks, drain fields and well heads are to be avoided.
Design & Construction
Rain gardens can be any shape, size or style. They are simple to construct and usually require little in the way of supplies and equipment. If you have a shovel and the willingness to do some digging, you can probably do it yourself. You will need plenty of organic compost to amend the soil, which is essential for increasing infiltration and promoting plant growth. Depending on the type of soil, other amendments might be needed to facilitate drainage. After plants are in place, you will need to top everything off with a layer of organic mulch to help retain moisture and suppress weeds. Maintenance is also simple: a bit of weeding, pruning and adding more mulch is usually what's required.
Plants and Planting
Think of a rain garden as having 3 different zones: “bottom,” mid slope and perimeter or berm. Plants in the bottom zone need to tolerate periods of flooding and will receive the most water for the longest time. Plants on the next level need to be a bit smaller and must also withstand moisture but for shorter duration. At the top or outermost zone are plants that are more typical of California and Mediterranean style gardens. Since our climate is dry for much of the year, all of the plants you select will need to do well with minimal water.
To slow the velocity of water entering the “basin,” rain gardens should be more densely planted than other types of landscaped areas. Grasses, sedges and other plants that form “clumps” are key to holding soil, supporting other plants and preventing erosion. Many California natives are well suited to these conditions but non-native plants with similar characteristics are also good options.
Plant Recommendations
- “Bottom” plant varieties include: douglas Iris (Iris douglasiana), creeping wildrye (Elymus triticoides), yerba mansa (Anemopsis californica) and torrent sedge (Carex nudata).
- Mid slope varieties: salt grass (Distichlis spicata), common or spreading rush (Juncus patens), wood rose (Rosa gymnocarpa).
- Top level or berm varieties: common yarrow (Achillea millefolium), ceanothus (Ceanothus spp.) California fuchsia (Epilobium canum), pitcher sage (Salvia spathecea).
More Solutions
If a rain garden isn't possible, there are other ways to retain direct and utilize excess rainwater. Rain barrels attached to gutter downspouts collect and store large amounts of water very quickly. Swales, rock-lined areas that mimic streambeds, can divert water, promote infiltration and add interesting landscape features. Swales can also be used in conjunction with rain gardens.
Rebates for rain gardens and rain barrels are available to San Mateo County residents. For more information, see San Mateo Countywide Water Pollution Prevention Program under “Resources” below.
To see a great video on residential rain gardens, go to:
https://www.youtube.com/watch?v=x40wEIQglqw&list=PLLgjyMTf6lO0oYUxC8gLzh_NjVzk98MwE&index=5
Resources
-UCANR Coastal California Rain Gardens: https://anrcatalog.ucanr.edu/pdf/8531.pdf
-San Mateo Countywide Water Pollution Prevention Program: https://www.flowstobay.org/rain-gardens-your-next-landscaping-project/
-US Environmental Protection Agency: https://www.epa.gov/soakuptherain/soak-rain-rain-gardens
-The Xerxes Society: https://xerces.org/blog/rain-gardens-are-winwin
-Groundwater.orghttps://groundwater.org/wp-content/uploads/2022/11/neb1.pdf
Maggie Mah is a UC Master Gardener who is in awe of nature's power and wisdom hopes lots of people will be encouraged to build rain gardens.
UC Master Gardeners of San Mateo-San Francisco County are volunteers who are trained under the auspices of the University of California to provide science-based information on plants, horticulture, soil and pest management at no charge to the public. For more information and to find out about classes and events in your area, visit our website where you can also sign up for our newsletter and contact our Helpline: http://smsf-mastergardeners.ucanr.edu/
- Author: Cynthia Nations
- Editor: Maggie Mah
What is a lawn? For many of us, those traditional squares of lush, green turf grass have not only been a part of the landscape, but also an icon of our American culture for generations. A manicured lawn symbolized prosperity and respectability. Learning how to mow was a rite of passage as well as a source of income for many enterprising kids. Now, with the increasing need for sustainability in all aspects of daily life, the thirsty, fertilizer-intensive lawn has become a focal point for change. Some homeowners are doing away with lawns entirely, opting for native plantings or succulents. But for those who love a beautiful expanse of green, there are sustainable alternatives that can thrive in a coastal environment and as well as contribute to fire safety.
“Greener” Grasses
Low-growing plants that replicate the look and feel of typical turf grasses are referred to as “grass alternatives.” Many are drought tolerant and require significantly less water than traditional lawns. This helps lower water bills and conserve an important natural resource. Grass alternatives generally require less maintenance compared to traditional grass lawns which means less time, effort, and money is needed to keep them healthy. An added benefit for allergy sufferers: grass alternatives don't produce pollen the way grass does. Some varieties have extensive root systems that help to stabilize soil and prevent erosion. Importantly, grass alternatives promote biodiversity by providing food sources and habitats for pollinators and other local wildlife. Lawn alternatives offer many types of unique and attractive landscaping options with a variety of colors, textures, and heights that can be included in rooftops and other locations where traditional grasses might struggle to grow.
Meandering Meadows
Meadow gardens are groups of plants, often natives, that are arranged and allowed to naturalize, thereby simulating a wild meadow. Flowering plants are often included but grasses are a key element. Creating a meadow garden allows you to include some of the coast side region's natural beauty at your doorstep and transform your outdoor space into a serene and bio-diverse haven. As you create your garden design and decide on the plants you will use, consider the height and width of each plant, and arrange them like a meadow with taller plants placed toward the back and shorter ones near the front. This will create depth and visual interest in your garden.
Fire Safety
In our current milieu, protecting your home from wildfires is crucial, and selecting grass alternatives can play an important role in reducing the spread of fire. Current recommendations call for non-flammable hardscaping materials like gravel, pavers or stone pathways within the first 5 feet away from your home to reduce the risk of ignition. Moving farther out, using green, low-growing vegetation, fire-resistant building materials and ensuring plants around the home are properly spaced, pruned and healthy can significantly reduce fire risks.
Here are some grass alternatives that are well-suited to the Northern California coast and are environmentally friendly:
Kurapia (Lippia nodiflora) is a low-growing, herbaceous, perennial groundcover belonging to the Verbenaceae family. Its dense and sturdy structure gives it excellent soil stabilization, aiding soil erosion, providing strong wee suppression, and tolerates a wide range of soil types, pH levels, and salinity.
Fescue (Festuca californica) is a native grass that thrives coast side and adds a graceful and natural appearance to a garden. It is an excellent choice for homeowners looking to create a meadow-like landscape, and it is drought-tolerant, low-maintenance, and (after established) requires minimal watering.
Idaho Fescue (Festuca idahoensis) shares many of the same qualities as California fescue including drought tolerance and adaptability to coastal conditions. Its clumping growth habit reduces the need for frequent mowing and maintenance.
Buffalograss (Buchloe dactyloides) is drought tolerant and enjoys sunny areas. Buffalo grass can be mowed to create a manicured look or left unmowed for a more natural appearance.
Pacific Beach Strawberry (Fragaria chiloensis) is a perennial native California species that grows 4-8 inches high with dark green leaves and produces small strawberries in the fall.
Blue Grama Grass (Bouteloua gracilis) is a drought tolerant native grass that forms dense clumps that resist fire spread. It requires little maintenance once established.
Muhly Grasses (Muhlenbergia) are ornamental and add aesthetic value to your garden. They are generally fire-resistant.
Ground covers: There are several hardy, drought tolerant groundcovers that reduce fire danger and conserve water. Creeping thyme, ice plant (Delosperma), or native sedges (Carex species) are good choices. Succulent plants, including many varieties of Sedum, have fire-resistant properties due to their water-filled leaves and can be used as ground covers and in rock gardens.
Landscaping with grass alternatives on the Northern California coast aligns with the region's commitment to environmental conservation and sustainability. Whether you decide on native grasses, ground covers, or meadow plantings, you can create a beautiful and eco-friendly garden.
Resources:
California Center for Urban Horticulture: https://ccuh.ucdavis.edu/kurapia
UC Marin Master Gardeners: https://marinmg.ucanr.edu/PLANTS/LAWN_AND_ALTERNATIVES/#alternatives
Cynthia Nations is a UC Master Gardener who planted Kurapia in her El Granada garden in 2017 and has appreciated its beauty ever since. This article was edited by UC Master Gardener Maggie Mah.
UC Master Gardeners of San Mateo-San Francisco County are volunteers who are trained under the auspices of the University of California to provide science-based information on plants, horticulture, soil, and pest management at no charge to the public. For more information and to find out about classes and events in your area, visit our website where you can also sign up for our newsletter and contact our Helpline: http://smsf-mastergardeners.ucanr.edu/
- Author: Anne Marie Tsolinas
- Editor: Maggie Mah
- Editor: Cynthia Nations
It's the New Year and a gardener's thoughts naturally turn to planning new and interesting plants. For those of
us living on California's Central Coast, the mild climate and long growing season supports a wide variety of
vegetation. But beware: there are some plants that should be avoided because introducing them to your
landscape can have consequences that go far beyond filling an empty spot in your flower bed. Apart from
poison ivy and other classic plant “no-no's,” the plants that should be on your radar are known as “invasive
plant species.” So, whether you're planning a large landscaping project or a simple garden refresh, here's what
you need to know.
What is an “invasive” plant?
Invasive plants are usually not native to a particular region but once introduced, they become established very
quickly. If allowed to proliferate, they will out-compete the existing vegetation and ultimately, disrupt the
natural ecosystem. A dramatic example of “invasives” taking over can be seen in California's iconic “golden”
summer landscape. Prior to European settlement, the hills would have been green year-round with deep-
rooted perennial native grasses dotting the open ranges. The aggressive annual grasses and weeds that
accompanied the introduction of livestock quickly took over and today, only 1% of California's native grasses
remain.
What's the difference between “invasive plants” and “weeds”?
Although they are vexing and you might think of them as invasive, there's an important difference between
common garden weeds and plants that are truly and destructively invasive. Your typical weed actually requires
what is known as “human disturbance” to establish and persist. “Disturbance” means conventional gardening
activities like soil tillage, fertilizing, irrigation, etc. Invasive plants (whether they are introduced intentionally or
not) do not need any help from humans and readily escape from cultivated areas, infesting all kinds of habitats
including wildlands, rangelands, and even waterways.
What do invasive plants do to a natural habitat?
Invasive plants disrupt an ecosystem by out-competing other plants, thereby reducing the ability of natives and
other non-invasive plants to survive. This change creates a “domino effect,” impacting every organism that has
evolved in the pre-invasive habitat including birds, insects, and other wildlife who rely on native plants for
shelter and food.
Where do “invasive“ plants come from?
According to the California Invasive Plant Council, about 37% of the species listed on the CIPC Inventory were
introduced accidentally through contaminated seed or carried along on equipment, vehicles, animals, human
shoes, etc. The remaining 63% were intentionally introduced and of those, nearly 80% came via the nursery
industry for use in ornamental landscaping. We now know the harm that invasives can cause, but ironically, it
is also easy to understand why so many of them have become popular: they tend to be attractive, and they
grow very well!
Although many invasive plant species that were introduced in California are no longer sold, others are still
available, and their impacts can be seen on a grand scale. Of these, Pampas Grass (Cortaderia selloana or Cortaderia jubata) is the poster child. This spectacular South American native was brought to Santa Barbara and introduced commercially as an ornamental in the late 1800's. Extremely hardy and fast growing, with massive clumps up to 13 feet tall, stands of Pampas Grass can be seen along the entire length of California's coastal areas. The plant's sharp leaf blades can be harmful to animals and humans, rendering it undesirable as wildlife shelter or food source. It's also quite flammable.
The list of invasive plants that are still sold in California goes on. Among the varieties of highest concern and
that are known to be invasive in our coastal region are these: Green Fountain Grass (Pennistem setaceum);
Mexican Feathergrass (Stipa/Nassella tenuissimo) Water Hyacinth (Eichornia crassipe); Yellow Water Iris (Iris
pseudoacorus); Highway Iceplant (Carpobrotus edulis) and Periwinkle (Vinca major).
Why it matters
Invasive plants cause harm to the environment, the economy and even human health. Fast growing woody
invasives create higher fuel loads, causing fires to burn with greater intensity. Invasive aquatic plants clog
waterways and block livestock from gaining access to water. According to the California Invasive Plant Council,
the state's annual expenditures on control, monitoring and outreach to address the issue of invasive plants
total more than $82 million dollars. The actual environmental cost is much more difficult to determine but
researchers at Cornell University estimate that the damage done by invasive plants in the U.S. costs over $120
billion each year.
Although it is one of the most bio-diverse places in the world, California has limited and diminishing
untouched natural habitats and over 30% of its native species are threatened. In many areas of San Mateo
County, housing developments are adjacent to large areas of open space, which makes them especially
vulnerable to “invasion” by problematic plants. By choosing non-invasive plants for your garden, you will help
to protect these sensitive areas.
Resources
--Plant Right: an organization partnering with retail nurseries to prevent the spread of invasive plants sold in
California. Plant Right identifies alternative garden plants that are comparably beautiful and provide the same
utility as invasive plants. http://www.plantright.org
--California Native Plant Society: https://calscape.org
--Cal-IPC website: www.cal-ipc.org
- Author: Cynthia Nations
- Editor: Maggie Mah
It's December and ‘tis the season to…think about blackberries! Our cool northern California coastal areas provide the perfect climate for growing sweet, flavorful blackberries. So take a break from the holiday rush and get going on summer's delicious crop. Here's how to have a bountiful harvest.
About Blackberries
There are a number of hybrids and also thorny and thornless varieties but, ultimately, there are two basic types of blackberries: trailing (with canes that are not self-supporting) or erect (with stiff, arching canes that are somewhat self-supporting.) Both types benefit from a trellis support and all varieties have similar growing requirements. To do their best, blackberries (also known as caneberries, bushberries and dewberries) need to be in a location that receives partial sun and in soil that is slightly acidic with a pH of about 6 to 6.5. Ensure that the soil is rich in organic matter and topped with a layer of organic mulch. Plants will need regular irrigation during the growing season so carefully check the soil at the base of the plant to determine if watering is sufficient. Root areas should be cool and moist but not wet and should not be allowed to dry out. Once established, apply compost or manure in late fall or early winter to allow rain to leach excess salts and as soon as the plants begin to put forth new growth in early spring, apply an organic granular fertilizer (20-20-20) around the base of the plants. This will provide the nitrogen needed for vigorous growth and fruit production.
How and What to Prune
A blackberry plant can live for many years but fruit grows only on the short lateral shoots of two-year-old canes (“floricanes”)which then die back after berry production is over. In spring, you can “tip prune” to force the canes to branch out and create more lateral shoots for fruit to grow on. Use sharp, clean pruning shears and cut to about 24 inches. If the canes are shorter than 24 inches, prune the top inch of the cane. In the fall, after fruiting is complete, prune to remove diseased, dead and spent canes by cutting to ground level. This will encourage the plant to produce more first year canes (“primocanes”), which will mean more fruit-producing canes the following year. If you already have blackberry vines, prune them now.
How and When to Plant
December and January are good months to plant dormant blackberries, but potted vines can also be planted in spring or summer. For bare root plants, trim the dead roots and dig a planting hole just large enough to accommodate the roots. Cover the roots with soil and press firmly to remove air pockets. Water thoroughly to settle the soil. After planting, cover the soil with mulch. Blackberry cultivars can be spread 3 to 4 feet apart in the row with 8 to 10 feet between rows. Cut the canes on newly set plants to 6 inches at planting time.
When to Pick
Blackberries do not continue to ripen once they are picked so it's important to pick fruit at the peak of flavor and sweetness. Since different varieties ripen at different times, you can extend your berry season by planting a few different kinds. Erect blackberry cultivars include: Black Satin, Cherokee, Cheyenne, Chester, Darro, Hull Thornless, Shawnee, and Triple Crown. Trailing blackberry cultivars include: Boysen, Kotata, Logan, Marion, Ollalie, and Silvan. (More information: https://ucanr.edu/sites/gardenweb/Berries/?uid=4&ds=466).
Troubleshooting
Purchasing certified disease-free plants from a nursery is a good practice. Although it is easy to propagate your own berry plants from canes, plants derived from another garden or grown near wild blackberry bushes could introduce unwanted diseases. If your blackberry plant looks healthy and blooms, but grows misshapen fruit or no fruit at all, chances are that your blackberry plants are affected by a blackberry disease. If you have more than one variety, one type may fruit while another, susceptible variety may not. On the coast, Anthracnose is a common fungal disease that tends to attack plants when the weather is cool and wet. The fungus can be spotted when the blackberry fruit starts to ripen but then wilts or turns brown.
If you decide to use a fungicide, it's important to determine if a fungus is indeed the culprit. Since symptoms could be due to something other than a fungus, using a fungicide might be a waste of money and do more harm than good. Contact the UC Master Gardeners Helpline (Phone: (650) 276-7430; Email: mgsmsf@ucanr.edu), to provide information and a photo of the problem. The Helpline will help determine if using a fungicide is necessary and, if so, what types of safe fungicides are best to use.
Insects (aphids, cutworms, thrips, mites, etc.) can also cause fruiting problems with blackberry plants. Check the bush carefully, particularly the undersides of leaves to see if the plant has unwanted pests. It is important to first identify the pest before determining the treatment. Sometimes the treatment could be as simple as hosing off aphids or spraying the pests with soapy water. Detailed information about blackberry diseases, pests, and treatments can be found here: http://ipm.ucanr.edu/PMG/GARDEN/FRUIT/blackberries.html
Cynthia Nations is a UC Master Gardener who continues to experiment with different blackberry cultivars coast side. This article was edited by UC Master Gardener, Maggie Mah.