The late comedian George Carlin once posed the question: "Why is there no blue food?” He speculated that the absence of “blue food” was due to the fact it was actually the secret to immortality and therefore not available to the rest of us. Fast-forward 50 years and, although George argued that blueberries were actually purple, it turns out he might have been onto something. The “blue” in blueberries comes from a group of phytochemicals called anthocyanins, powerful antioxidants which may help your body defend itself against a long list of diseases. Eating blueberries is not likely to make you immortal but there is no doubt that they are highly nutritious and, as such, are commonly touted as a “Superfood.”

In addition to being delicious, blueberries are easy to grow and make attractive additions to the home garden with profuse clusters of white or pink blossoms in early spring and colorful foliage in the fall. Since nothing is healthier or more delicious than fresh picked blueberries, here's how you can grow your very own “Superfood.”

Blueberry plants that do well in the mild winter conditions of our coastal areas include Southern Highbush, a hybrid of native Highbush and Southern Lowbush Blueberry varieties. These cultivars are also known for producing lots of sweet, flavorful berries. Other variations on Southern Highbush blueberries include Reka, O'Neal, Gulf Coast, Jubilee, Misty, Georgia Gem, and Marimba.

Unless you want to share your blueberry harvest with the local bird population, you may want to protect your harvest with bird netting. (Note: netting is a bit pesky, and it won't deter squirrels!) Install the netting just as the first green berries show a blush of violet. Once berry production slows down and your main harvest is done, you can remove the netting and allow your feathered friends to enjoy what's left of the berries. They will return the favor by removing any lurking caterpillars. After several years, you may see that your original plants have sent out rhizome shoots and multiplied the number of fruit producing stems in the garden bed.

For more information, check out these resources:

Bruce Goren is a Master Gardener who has developed his own tomato variety, San Francisco Sunrise. Bruce is also doing experimental grafting to see if fruit trees can produce sub-tropical fruits in chilly San Francisco. You can find more about Bruce's work, read his comments, and see his photography on Instagram at IG-@SFfruitGardener. This article was edited by UC SM/SF Master Gardeners Maggie Mah and Cynthia Nations.

Is it permeable? Landscape or “weed blocking” fabric is made of tightly woven fiber, usually
polyester or plastic, both of which are derived from petroleum. There are different grades and
thicknesses, which will have correspondingly different degrees of permeability. Initially, they
are somewhat porous, allowing a certain amount of water and air to move through the fabric.
Unfortunately, permeability decreases in short order as the small holes that create porosity
gradually become clogged with dirt and debris. This is where the trouble starts.

What goes on below the surface? While not visible to the naked eye, healthy soil teems with
billions of beneficial organisms that depend on the movement of water and vital gases (oxygen,
carbon dioxide) between the atmosphere and the soil. As permeability decreases, these
components become more and more restricted. Deprived of oxygen, carbon dioxide and water,
soil microorganisms die off, leading to a downward cycle. Natural processes start to shut down
and plants start to appear less and less healthy. Once uncovered, the degraded soil may appear
cracked, compacted, and will very likely smell rotten. This is because the natural process of
decomposition has been interrupted and the healthy microbial community has died off.

Rooting for roots. Plants that are surrounded by increasingly clogged landscape material have a
hard time, too. Vegetation that is planted in good, properly irrigated soil grows deep roots in
the process of seeking out nutrients and moisture. This leads to healthy plants that are more
resilient to stress. Conversely, plants that are surrounded by a cover of landscape fabric (which
can be bone dry even after a deep, soaking rain) soon spread their roots out closer to the
surface. Eventually, roots may appear at the edge of the landscape fabric but despite a
gardener's best efforts, plants in this scenario will not do well.

Mulch: always good? Landscape fabric is often topped with a layer of organic mulch such as
wood chips. Although mulch is normally a very good thing and a top dressing of it certainly
looks more attractive than naked landscape fabric, it can't do what it does when it is in direct
contact with the native soil and becomes counterproductive. Why? Instead of the usual process
of decomposing and adding valuable organic matter to the soil, the mulch particles just break
down on top of the fabric and add more particulates to clog things up even more.
Still in the weeds? If you are determined to get the upper hand in the battle against weeds,
consider sheet mulching and other beneficial practices that will minimize time and effort and,
at the same time, help your garden to thrive.

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

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.