In this episode of Plants to Dye for – season 2, we're dyeing with cochineal. Cochineal dye comes from parasitic insects (Dactylopius coccus) that live on the prickly pear (or nopol) cactus and are native to Mexico, Central and South America and the Canary Islands. They live in colonies and obtain moisture and nutrients from the cactus. The females produce carminic acid, which they use to deter insect predators. A natural red dye is derived from the carminic acid, which can be pushed to the shades of red with cream of tartar, or fuschia with soda ash.
The dye has been used to color food and to dye fiber for centuries. Farmers brush the cochineal off the cactus leaves to harvest, and then dry the insects.
I purchased cochineal from Dharma Trading right here in the Bay Area.
They import dried insects that are sustainably farmed in Peru, a major exporter of the product. Dharma recommends using 20% Weight of Fabric (WOF) for cochineal. This value may differ per vendor, depending on the intensity of carminic acid in the insects (for example, Maiwa recommends 3-8% WOF for a medium shade using their product). Cochineal dye is very sensitive to the pH, so distilled water is recommended. The dye also performs best when the dye bath is kept between 180 and 200° F.
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Dried cochineal insects
The weight of fabric for this project is 385 grams (or about 13 ounces).This includes four white cotton dish towels, and one dish towel that has already been dyed with madder, which I plan to use for an over-dye experiment. Twenty percent WOF for 385 grams of fabric is 77 grams of cochineal, or 2.7 ounces. I have 2 ounces of cochineal – close enough. Fabric should be scoured and mordanted. We used a gallnut mordant, followed by a bath of 15% WOF alum and 2% WOF soda ash as a brightener. See Scouring your Fabric (Soaking Method), Mordanting Fabric (Oak Gallnut), and Mordanting Fabric (Alum Brightener).
Outdoor studio with basic equipment
For this project you need basic dye equipment, and a well-ventilated workspace. You need a soaking pot, a dye pot, a heat source, and a candy thermometer to keep the dye bath at a consistent temperature. You need a grinder, a small pan or can, strainers, and jars in which to store the decanted liquor and the dye bath. For safety, wear a face mask when working with fine powders, and rubber gloves when working with soda ash.
Add to a pan, and cover with 3 inches of distilled water.
Bring to a boil, and then turn off heat. Let soak overnight. (Note that some instructions say to simmer for 30 minutes, but I didn’t do that.)
The next day, pour the extracted liquor into a jar, filtering out the pulp.
Add the pulp back to the pan.
Repeat steps 2-5, two more times.
First, grind the dried cochineal insects to release the carminic acid. I’m using my marble cutting board and rolling pin, metate style (but am protecting the marble with layers of freezer paper). You could also use a dedicated coffee mill, or small food processor, one that is not used to process food.
Makeshift metate and supplies for grinding the cochineal
Ground cochineal powder
Add the ground powder to a small pan (I’m using a can that once held enchilada sauce). Cover the powder with three inches of distilled water. Cochineal is sensitive to pH, so distilled water is recommended because its pH is neutral. Tap water may be more acidic.
Use distilled water when working with cochineal
Stir together the cochineal powder and distilled water
Bring the mixture to a boil, and then turn off heat. Let soak overnight. The resulting liquor is deep red and glossy. The next day, pour the extracted liquor into a jar, filtering out the pulp. Add the pulp back to the pan, and repeat two more times to continue extracting dye pigment.
The extracted liquor is glossy red
Strain the extracted liquor through a sieve into a jar, and reuse the pulp
Note that you can continue extracting color several more times, although the color becomes weaker. The number of times depends on the concentration of carminic acid. I extracted dye a total of six times over the course of a week. You can see that the resulting dyestuff becomes lighter and lighter. Compare the jar on the left (extractions 1 and 2) with the jar on the right (extraction 6). I could have continued, but have limited storage space, so chose to stop with six extractions.
Extractions 1-6, from left to right
I'm using extractions 1-3 for this dye project, and am storing extractions 4-6 in separate jars, so it doesn’t dilute the dye from the first three extractions.
Extractions 1-3
According to Maiwa, some dyers keep the remaining pulp in a jar of water for several weeks and use it for future dyebaths. I’m storing my pulp in the freezer for future experiments.
Allow to cool in dye bath for maximum color absorption.
Rinse and hang to dry.
Presoak prepared fabric before dyeing
Add water to the soaking pot and presoak the prepared fabric for at least an hour (or overnight). This helps ensure that the fiber soaks up the dye evenly. Stir occasionally.
Combine extracted dye and distilled water
Pour the cochineal liquor into a pan of distilled water. I started with a gallon, which is plenty for the fabric to move around the pan when stirred. Add more water as needed. Simmer your dyestuff for an hour keeping the temperature between 180 and 200° F.
Simmer the dye bath, keeping the temperature within range
Add the wet dish towels. Stir to loosen the fabric. Add additional water if needed. Simmer the fabric for an hour, keeping the temperature between 180 and 200° F. Continue to stir periodically for even dyeing, turning fabric frequently while simmering. Surprisingly, I did not have much trouble controlling the temperature of the cochineal dye bath, compared with the madder project (see Dye Project: Madder Root).
Let the dye bath cool
Turn off the heat and let the pan cool. Leave the dish towels in the dye bath for as long as you want. I covered the pot with foil, and soaked overnight for saturated color.
Rinse fabric until the water runs clear
Squeeze out water
Squeeze out excess dye from the dish towels into the dye bath. Rinse the dish towels in cool water until the water runs clear. The color was so saturated, that I used more water than usual to rinse. Run the dish towels through the washing machine’s rinse and spin cycles without soap.
Use the rinse/spin cycle a couple of times
Air dry the fabric
Let the towels air dry. In a couple of weeks, run the towels through the washing machine using Synthrapol and rinse. Include a piece of white cloth to test colorfastness. Air dry again.
Cotton dish towel dyed with cochineal (fuschia)
You can save and re-use the dye bath for lighter shades. Preserve the dye in glass jars to reuse in future projects. The color may be less intense but is still usable. Cochineal can be used in combination with other dyes, such as madder or logwood.
Last fall, I noticed the squirrels were leaving many acorns from our Quercus agrifolia on the ground, rather than stashing them.
Typically they grab nuts as soon as they fall, scamper to a hiding place, glance around,
and then quickly bury the nut. Sometimes they double-back, dig up the nut, and
rebury it somewhere else. Instead, they were ignoring many nuts, and
burying only a few.
Acorns from Quercus agrifolia in the Bay Area.
Naturally, this behavior change caught my attention. My
folks were visiting from Alaska, so we launched an investigation. The first
thing we noticed is that almost all of the ignored nuts had a bore hole in
them. My dad split open a healthy nut, and several nuts with bore holes. The
unhealthy nuts were filled with frass, but no inhabitants.
Acorn with a bore hole.
Two insects that target acorns in the San Francisco Bay Area,
are filbert worms (Cydialatiferreana)
and several species of filbert weevils (Curculio
spp.). After mating in spring, the female filbert weevil drills a small hole
in an immature acorn, and inserts her eggs; the female filbert worm lays her eggs
on the outside of an acorn, and the larvae bore into the nut. In both cases, the
larvae develops and feeds in the acorn, leaving its frass; and then bores out in
the fall, moving to the soil until spring. The number of infected acorns varies by year,
environmental conditions, and the individual tree. The infestation does not harm
the tree, but the acorns are infertile.
Left: healthy acorn. Middle and right: infested acorns.
Interestingly, birds and squirrels can discriminate between
the healthy and infected acorns. Much like humans, they separate the infested nuts,
and preserve the healthy!
Learn More:
Filbert Pests in Live Oaks (prepared and edited by John M.
Harper, Richard B. Standiford, and John W. LeBlanc)
Pests of Acorns (prepared and edited by Richard B.
Standiford and Pamela Tinnin)
Nematodes can be a threat to turfgrass, and have been found
in golf courses, parks, and lawns in the San Francisco Bay Area. Spiral nematodes
(Helicotylenchus spp.) are one of
many nematode species that are found in the soil. Spiral nematodes have a wide
host range, and do not cause excessive damage, but they can reduce the vigor of
plants in a monoculture host like turf grass. Mature spiral nematodes are up to
1.2 mm long, and are so named because they curl up into a spiral when dead or
relaxed. They are ectoparasites, meaning they feed outside the cell, although some
may act as partial endoparasites—inducing growth of a food cell in which they bury
their head to feed for long periods of time, before moving on to create a new food
cell. These food cells do not grow like a gall, but the cell composition does
change.
Spiral nematodes are all females, reproduce without mating,
and lay individual eggs in the soil (unlike the root rot nematode that lays an
egg mass). The first molt occurs within the egg (J1). If moisture is present in
the soil when the egg hatches (J2), the nematode is motile and works its way to
a plant root where it can feed. The nematode undergoes three more molts (J3 and
J4), before becoming a mature adult. Populations are highest in late summer and
early fall and lowest in spring when cold temperatures inhibit reproduction.
Spiral nematode turf damage is associated with bluegrass and
Bermuda grass. Above ground symptoms include stunting, reduced plant vigor,
yellowing or brown patches in the turf, and areas that succumb to weeds. There
is typically a “hot spot” or dead zone, which is heavily infested. These symptoms
can have other causes, so soil analysis is required to diagnose the problem: http://youtu.be/taW-VM-4IRw
For management tips, see the Integrated Pest Management(IPM) site. Prevention is the best approach, but strategies like crop rotation
are difficult for turf. Chemical treatments exist, but some of them cause
damage to turf, or must be repeated, since they also kill beneficial organisms that
keep other diseases at bay. See UC IPM Pest Management Guidelines: Turfgrass
(page 72) for additional information.
Root-rot nematodes are from the genus Meloidogyne, and thrive in hot climates with short winters. They
are not host-specific, and infect the roots of a wide host range, including
flowers and vegetable crops (tomato, green pepper, corn, grains, and so forth).
They are sedentary endoparasites—living and feeding from within their hosts.
Females lay their eggs in a gelatinous mass on a root gall
surface; ensuring a protective, moist environment in which the eggs develop. The
first molt occurs within the egg (J1 stage). After the eggs hatch, the second-stage
juveniles (J2) are motile. They leave the egg; penetrate the root with their
stylets, just behind the root cap; and secrete a liquid that stimulates growth
hormones in the cells, causing them to divide and swell. This forms root galls
that become permanent feeding sites. After molting through two more juvenile stages,
(J3 and J4), reproductively mature females lay a new batch of eggs. This lifecycle
occurs over the course of several weeks, so, in the right environmental
conditions, plants can become infected very quickly. If the galls become separated
from the roots, the eggs can exist in the soil for years, until the right
conditions and a suitable host are available.
Galls on carrot from root-rot nematode. Photo by Claudia Nischwitz.
Copyright, ASPnet.
Above ground, plants exhibit symptoms that are similar to
any disease that harms the root system, including stunted growth, wilting, and
yellowed leaves. Reduced crop yield also results. To help with diagnosis, it is
necessary to have the soil analyzed and to check the roots for galls, if at all
possible.
For management tips, see the Integrated Pest Management
(IPM) site. Since the eggs can remain in the soil for years, management is
difficult. The solution is prevention – using resistant plant varieties; rotating
crops so the nematodes cannot continue their lifecycles from season to season; leaving soil fallow periodically; amending
the soil to keep it healthy; planting when nematodes are less active; and keeping
infected plants or material from contaminating uninfected areas. Soil solarization,
the process of heating the top 8 - 12 inches of the soil, can temporarily
reduce the nematode population. Currently no chemical or soil fumigants are
available to the home gardener.
This time I’m researching nematodes, which are non-segmented
round worms found in soil, water, and extreme environments such as deserts
and ice fields. A few can be seen with the naked eye, but most are tiny and require
magnification. For resources I’m using Essential Plant Pathology, information from my plant diseases course at Merritt
College in Fall 2012, and Five Kingdoms.
Keep in mind that most nematodes are beneficial – they aerate the soil, consume
detritus, feed on bacteria and other small life forms, and circulate organic and
mineral soil components. Others cause considerable damage to crops, turf, and plants
in the landscape. Nematodes can be found in the San Francisco Bay Area.
Nematodes are categorized as Eukarya in the Animalia kingdom. About 10% of all
nematodes are plant parasites, and require a living host (obligate parasites). They
are aquatic and typically live, feed, and move in the soil. They use a specialized
feeding structure—called a stylet—to penetrate plant tissue, probe, secrete proteins
and polysaccharides, and ingest cellular contents. Most nematodes are migratory
and move from cell to cell to feed (ectoparasites). Others are sedentary and
remain embedded in a plant throughout their lifecycles (endoparasites); some
endoparasites induce formation of specialized feeding sites, such as galls,
where they live and feed. A few do not fit either of these categories.
The female nematode lays hundreds of hardy eggs (some
species do not require male fertilization of the eggs). The eggs can exist in soil for years or decades, until the right environmental conditions exist for them to infect a plant. Their life cycle
includes four juvenile stages. Nematodes molt, shedding the outside cuticle and part of
the lining of the stylet, from stage to stage as they grow. Juveniles look like miniature
adults through all stages (they do not undergo a metamorphosis from stage
to stage).
Take a look at several nematodes; of special interest (1) views
of the stylet at 57, 107, and 145 seconds, (2) a root rot nematode at 159
seconds, and (3) a needle nematode at 202 seconds: http://youtu.be/Qf8oGjqyXFc
I’m afraid my Plant Diseases class from Merritt College in
Oakland has despoiled me – I am always on the lookout for plant diseases! End-of-summer
is a great time to spot them, as many plants have spent their reserves on reproduction, and are more vulnerable to attack.
Here are some of the diseases I spotted in Clear Lake; oaks seem especially hard hit.
Sudden Oak Death– I wasn't close enough for direct inspection, but this looks like SOD from afar; caused by the water mold, Phytophthora ramorum.
Oak Gall – these little "nipples" are galls caused by asexual reproduction by the oak gall wasp.
When the wasp lays its eggs, hormones kick off a type of genetic engineering to create the perfect nursery (the gall).
Oak Apple Gall – this "strange fruit" indicates sexual reproduction by the oak gall wasp.
Tent Caterpillar – we found these gauzy structures all over foliage. The residents had already moved on.
In many cases, these diseases do not cause permanent damage.
An organism is simply taking advantage of a situation, and working through its
own life cycle. After the class, seeing plant disease is not necessarily alarming.
Plants in nature are rarely perfect; instead, they are teaming with all sorts
of life forms. Learning to enjoy the whole ecosystem of a plant, both good and
bad, can add to the enjoyment of nature as well as the garden. And raising your tolerance for imperfection can lower the need to combat the imperfect with pesticides.
The Grape Leafroll Associated Virus (GLRaV) colonizes the
phloem in the plant’s vascular system, cutting off distribution of nutrients to
leaves, shoots and fruit. This delays maturity of the grapes, reduces fruit
yield, and lowers accumulation of sugars (the Brix), affecting wine quality.
Symptoms include reduced vigor, yellowing of the leaf margin and veins, and the
characteristic under curl of the leaves. The symptoms are more noticeable in
red varieties than white varieties. Symptoms are typically most evident in
mid-August, but, in some cases, there are no visible symptoms. The virus is a
group of ten strains, identified as GLRaV- followed by a number. Take a look at the symptoms on a variety of grape types:
According to the brochure, "Grapevine Leafroll – an Increasing Problem in the Finger Lakes, the US and the World", published
by the Cornell University Cooperative Extension, this is a worldwide problem threatening
many grape-growing regions. The virus has been found in both eastern and
western United States grape growing regions, including California. Even the San
Francisco Bay Area backyard gardener may encounter the virus.
The virus spreads through infected bud wood cuttings and
graft unions. If the grafts are not clean, infected starter plants can be distributed
unwittingly around the globe. European researchers discovered the virus is also
spread through insect vector - Pseudococcus
mealy bugs (grape, obscure, and longtailed) and soft scales (Parthenolecanium corni and Pulvinaria innumerabilis). The vectors hitch
hike on farm workers, equipment, and plant debris, and can quickly spread from an infected
field to a neighboring clean field.
Since vines cannot be cured once they are infected, the best
strategy is preventing infection. Plant only certified clean root stock. Inspect
the plants routinely, looking for symptoms and signs. Manage mealy bugs and
soft scales using organic methods. Once infection is detected, replace the infected
vines with certified clean stock at once. Testing is available for several
strains of the Grape Leafroll associated viruses; see the U.C. Davis Integrated Pest Management (IPM) site for information.
The Tomato Leaf Curl Virus (TYLCV) infects tomato plants,
and sometimes other hosts in the Solanaceace
family (nightshade and jimsonweed). Symptoms include small leaves that curl
upward, crumpling, and yellowing on the margins and veins. Flowers fall off the
plant, reducing the crop. The plants themselves look stunted—due to shortened internodes—giving
the plant a bushy appearance. Other hosts may exhibit minimal symptoms, or no symptoms.
According to the Tomato Yellow Leaf Curl brochure, published by the University of California Agriculture
and Natural Resources Statewide IPM Program, the disease was first observed in
Israel in the 1940s; spread to the Caribbean islands and southeastern United
States in the 1990s; moved to northern Mexico, Texas, and Arizona in the 2005-2006;
and was found in a greenhouse in Imperial County in 2007. The disease thrives
in tropical and subtropical environments, and in Mediterranean climates.
Upward leaf curling and reduction in internode length in tomato infected with TYLCV.
Copyright, ASPnet
Bemisia whiteflies
and some leafhoppers are the main vectors for the disease. After feeding on an
infected plant, the insect is infected for its lifetime and spreads the virus
by feeding on uninfected plants. When tomato plant hosts are not available, it is
thought that the virus can exist in weed hosts. The virus is not transmitted in
seeds or mechanically (by touch), but can be transmitted if infected plants are
transported to uninfected areas. If the virus spreads to California, it could have
a significant negative impact for commercial tomato growers, and for backyard tomato
enthusiast
For management tips, see the Integrated Pest Management
(IPM) site. In general, recommendations include planting TYLCV-resistant
varieties, maintaining “tomato-free” periods when there is no host, eliminating
weeds that could be hosts during tomato-free periods, removing diseased plants,
avoiding transport of infected plants to uninfected areas, and managing
whiteflies. TYLCV symptoms resemble symptoms for other diseases, but accurate
tests are available to identify the virus.
Viruses are an interesting classification of plant diseases,
though they differ from the kingdoms we have looked into so far (bacteria,
plant parasites, and water molds).Viruses are comprised of bits of nucleic acid (genetic code) encased in
protein. They cannot live or reproduce outside of a host cell, but they can
orchestrate their reproduction in host cells and can cause disease. Viruses can
infect bacteria, algae, fungi, plants, and animals. Viruses are typically host-
specific, and are very small (20 – 2,000 nanometers). Virus shapes can be rod-like, spherical, or icosahedral
(20 facets). Nearly 1,000 virus species infect plants.
According the Essentials of Plant Pathology (by Dr. Gail L
Schumann and Dr. Cleora J. D’Arcy), virus origin theories includes:
Descendants of genes that escaped from host cells.
(Interestingly, Lynn Margulis and
Karlene V. Schwartz observe in Five Kingdoms An Illustrated Guide to the Phyla of Life on Earth that viruses
seem more closely related to their hosts than to other members of their
species).
Evolved as independent life forms, likely predating other
forms of life.
Viruses are typically named after the first economically
important host in which they were found, and the symptom they induce. The
initials of the name are used to identify it. For example, the first
well-studied plant virus was the Tobacco Mosaic Virus, or TMV.Mosaic refers to the yellow and green mosaic
pattern the virus exhibits in the tobacco plant leaves (the symptom). In the
San Francisco Bay Area, several viruses are a threat, including the Tomato Yellow Leaf Curl Virus (TYLCV), and the Grape Leafroll Virus
(GLRaV).
Fig Mosaic Virus (FMV) - in residential garden in Berkeley, California
Since viruses are not mobile, they are typically spread via
insect vector or nematodes, especially those with piercing-sucking mouth pieces
(stylettes). When an insect or nematode pierces a plant for the sap, viruses may be sucked
up and stored in the vector's body, and then deposited in
the sap of other plants as it feeds. When deposited into a plant cell, the
virus is replicated. Variability may arise from mutation. Viruses rarely kill
the plant, but may cause symptoms such as stunting and dwarfing, chlorosis (yellowing),
mosaic patterns, ringspot, flower break, leaf roll, and fruit deformation.
Viruses do not produce survival structures, but many can exist as inanimate
molecules for years in the soil or leaf debris without a living host (others
can exist only for a few hours or minutes). Since we have no cure for viruses,
prevention is the best course of action, including managing insect vectors that
transport the virus.
For a great resource for learning about plant diseases, I recommend
the text book we used for the Plant Diseases class at Merritt College last
fall. Essential Plant Pathology was
written by Dr. Gail L Schumann and Dr. Cleora J. D’Arcy, and published by
American Phytopathological Society Press in 2010 (Second Edition).
It is not your standard text book, in that the text is very
accessible (except for a few deep-dives into genetics), and it is filled with
graphics, photos, case histories, high-level summaries, references, web
resources, and a CD, all of which are great for visual learners. Case
histories, called Disease Classics, appear throughout the text, and describe
Host, Pathogen, Symptoms and Signs, Disease Cycle, Management, and Significance.
A glossary and index help the reader grapple with new concepts and terminology.
The presentation is organized around plant diseases from the
five kingdoms – fungi, bacteria, animals, plants, and protoctista, as well as
viruses and environmental factors. The idea is that by understanding the phylogeny
of organisms, you can use the information to identify the pest or disease,
understand its life cycle, and use the knowledge to mitigate the problem. The
book’s emphasis is on learning a system for diagnosing plant diseases, rather
than memorizing many plant diseases.
I spent a fabulous morning touring Oak Hill Farm in Sonoma County. About 15 of us gathered at the Red Barn off Sonoma Highway at 10:00 a.m., then David Cooper, the farm manager, lead us on a tour of the historic farm’s barn, greenhouse, orchard, and fields. Cooper has degrees in chemical engineering, but decided being stuck in an office was not for him. He's been a farm manager for about four years now.
The farm is beautifully situated – surrounded with oak and mixed evergreen forest. We learned about the farm’s organic and sustainable farming methods, which have been in place since the 1950s when the owners purchased the farm. They grow a whole array of fruits and vegetables, rather than planting a single crop. They practice crop rotation, plant cover crops to enrich and protect the soil between plantings, and allow a beekeeper to keep beehives on the property (honey for him, pollinators for Oak Hill Farm). The property is alive with bees and birds (and gets its share of pests in the form of deer, crows, squirrels, and gophers).
The produce is sold directly to several restaurants in San Francisco, at Farmers’ Markets (Ferry Terminal and Jack London Village), through CSA subscriptions, and at the Red Barn on the property. The tour is offered the first Saturday of the month. It is a great opportunity to see a farm in operation, and spend some time surrounded by beauty, growing things, and the natural world. To learn more: http://www.oakhillfarm.net/.
“Harvest” might be a little grandiose for our tiny 8 feet by 4 feet raised bed, but we are enjoying a continual trickle of peas, lettuce, radishes, and, soon, cherry tomatoes. I’m not sure if the pole beans will ever materialize – lots of vines and blossoms, but no sign of an actual bean. We typically get our heat in September and October, here in the San Francisco Bay Area, so there may still be hope. One carrot is left to harvest; the others were eaten by garden pests as sprouts.
We’ve had a number of garden pests in the form of marauding deer who love tomato blossoms, and skunks who love lettuce (or slug salads). I try to live harmoniously with these woodland creatures, and count on a certain amount of pilfering; but I may rethink this pacifist philosophy next year, and cloak the garden bed in deer netting!
Raised bed vegetable garden after three months
I’m grateful that our family’s survival does not depend on this little garden plot, because we would surely starve. Still, it is a pleasure to plan, plant, and tend a vegetable garden, and very satisfying to eat the produce.
