Terra Viva Organics
& Terra Viva Update
Ahead of Powdery Mildew
in the Organic Garden
with Wilted Greens, Goat Cheese and Raisins
- We had an incredible
response to the Organic Grub Control article in last
month’s issue. Many other websites like ICanGarden.com,
and Dollar Stretcher reprinted the article for their
audience so we had a hard time keeping nematodes in
- We hope to see many
of you at the upcoming Van Dusen Flower & Garden
Show in Vancouver, June 2-4. Our booth has already
attracted much attention for our ladybug give-away.
We’ve been featured in the Vancouver Courier, The
Province and The Vancouver Sun newspapers.
- Hopefully, your own
pest problems are under control. If not, these yellow
sticky traps are a great way of catching pests,
especially flea beetles. The wire
holder also helps you mount the cards in containers
- Ursula Dole, one of
the authors of the Greenbug
Guide to a Totally Organic Garden has formulated
a number of pest control products that you can make
at home. If you don’t have time (or the energy) to
collect ingredients, they’re pre-mixed for you.
We’ve also added our own line of fertilizer
mix made from worm casts. The potting mix is wonderful
to work with – it holds moisture well and releases
nutrients over time without burning plants. Plus,
casts don’t smell like many other fertilizers
so the mix can be used on indoor plants too!
- Finally, to help
you with your fall/winter garden, we’ve put together
of 5 different organic seed packets that can all be
used to grow your own Stir Fry. If planted by late
July-early August, you’ll be harvesting well into
the fall & winter.
Powdery mildew is a common disease on many types of plants.
In fact, it is one of the oldest plant diseases on record
– Theophrastis wrote of powdery mildew on roses in 300
B.C. Although different species of fungi cause the disease
on different plants (Erysiphe
infects vegetable crops and flowers; Podosphaera
species infects apples and stone fruits; Sphaerotheca
species infects berries, roses, some vegetable crops,
and stone fruits; and Uncinula
necator infects grapes), the infections are
all characterized by a powdery white to gray fungal growth
on leaves, stems and heads.
Contary to popular belief,
powdery mildew generally does not require free water
to establish and grow. Infection can actually occur
on dry leaves. Warm temperatures and shady conditions
encourage the fungus to grow and spread. However, the
spores and mycelium are sensitive to extreme heat and
Powdery mildew usually
shows up on leaf and stem surfaces and does not directly
affect most vegetable fruits. However, it can affect
the flavor of melons and squash and reduce their yield.
Woody species such as grapes, fruit trees, roses, crape
myrtle, and sycamore are more seriously affected; new
growth is often distorted. The young fruit of apples
and grapes can also develop rough skin due to powdery
All species of powdery
mildew fungi require living plant tissue to grow. On
perennials, they survive on buds and stem tissue. Certain
weeds will also act as hosts through the winter. The
optimum temperature for infection is between 68 to 77
degrees F and relative humidity between 40 to 100% is
sufficient for the spores to germinate. Low, diffuse
light also seems to favor powdery mildew development.
The mildew can spread
rapidly since the disease cycle can be completed in
as little as 72 hours. However, it commonly takes 7-10
days from the time of infection to the development of
symptoms and secondary spore production.
In most cases, good cultural
practices will adequately control powdery mildew:
- Select powdery mildew
resistant varieties. This is particularly true of
roses. For lawns, shade tolerant grasses such as creeping
red fescue can be planted.
- Plant in full sunlight
in a well-drained area.
- Do not crowd plants.
Air flow and ventilation will discourage mildew growth.
- Powdery mildew thrives
where high rates of nitrogen have been used. High
nitrogen promotes tender leaf formation, causing dense
stands that are more susceptible to infections. Adequately
fertilize but avoid stimulating succulent growth.
Organic fertilizers or slow-release formulations of
lawn fertilizers are good choices
- Prune infected plants
to get rid of infected parts and increase airflow.
If the infestations are severe, remove and destroy
the plants that are infected.
- Disinfect your pruning
tool in a bleach solution of one part household bleach
to four parts water after each cut.
- Watering plants in
the morning gives the plants the rest of the day to
dry off, discouraging establishment of diseases, including
Sulfur is highly effective
against powdery mildew if used in a protectant program
with a minimum of 7 to 14 days between applications.
Garlic naturally contains high levels of sulphur and
a few cloves crushed in water can be used to make a
homemade spray. Apply a sulfur-based fungicide at
first evidence of mildew and repeat applications
as necessary. Proper timing of fungicide applications
is critical to successful control so make sure to begin
at the first sign of the disease.
However, sulfur can be
damaging to some squash and melon varieties. Another
option is to spray once a week with a solution of baking
soda. Baking soda increases the surface pH of the leaf
making it unsuitable for the growth of powdery mildew
spores. Be sure to spray the undersides of leaves as
well as the upper surfaces when using any of these sprays.
Here’s a recipe to make
your own spray:
- 1 teaspoon baking soda
- 1 quart water
- a few drops of liquid
Before treating your plants,
test the spray on a few leaves to make sure they are not
For more information on
powdery mildew, you can refer to the following websites:
Control of powdery mildew
in apples & grapes: http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn007.html
Powdery Mildew on roses:
Powdery mildew on tomatoes:
Hamir is an agronomist and President of Terra Viva
Organics. When she’s not planting peas or picking zucchini,
she answers questions about organic gardening at: firstname.lastname@example.org
A mini organic garden can
give you wonderful vegetables, which are pesticide-free
and delicious. It is not really necessary to have a large
garden area to grow plants or vegetables. All you will
ever need in vegies will grow in a reasonably small plot.
The no-dig garden method
has been proven as successful all over the world. What
you need to do is identify the area where you would
like to start. Choose an area where there is sunlight,
with access to water, mark it out and you are ready
to start planning.
What you will need to
- Pieces of wood or something
to use to box in the area chosen.
- A bale of alfalfa hay
- A bale of straw
- Some old newspapers
- A load of compost
- Manure or a complete
- A bit of energy, motivation
Be thorough with the preparation.
Don’t make it big to start, say 10 feet (300 cm) by
5 feet (150 cm) and choose which vegetables you would
like to grow. Good choices are lettuce, beans, tomatoes,
Swiss chard, and radish.
The site to choose?
Choose an open area, preferably
facing north/south. Plenty of sunshine and not much
wind are important factors to consider. If you are working
on concrete your windbreak could be shrubs in pots.
This is an ideal way to do it as you can move pots around
and place them where they will be more effective.
Mark out your site and
box it in. If it is on concrete, join the boards to
make it strong. If it is on ground, do a bit of leveling
first. Don’t worry about grass as we are going to cover
this over. Even if the ground is rock-hard, this method
works. You can build a no-dig garden on any base.
Now that you have the
base down, cover the bottom of the box with newspapers.
Use complete papers, opened up and overlapped. Tuck
the paper under the framework if you are building on
an old garden bed. After the paper, cover the bed now
with the Lucerne hay and use each layer piece as bedding.
This needs to be about 2 inches (50 cm) in thickness.
Water this area very thoroughly at this stage.
Sprinkle some of your
fertilizer, blood and bone, or even a liquid organic
fertilizer over the whole area. Next, we need to add
the compost and this needs to be only about 1 inch (25
cm) in thickness over the area. At this stage, rake
it over so that the compost is even and flat across
Now, put a layer of straw
fairly loosely over the area. Add some more fertilizer.
Put another layer of compost on top of this and add
some more fertilizer on top again. It’s time now to
put the final layer of Lucerne hay, making sure that
it is all fairly level.
Buy your seeds or seedlings
as its time to plant. This is the most rewarding part
of this job, other than the harvesting later on. Make
small holes in the hay and plant into the compost, firming
the hay around the plants. This hay will act as an insulator
and stop any drying out. Alternatively, you could place
another layer of compost on top and plant into this.
It’s just a matter of
maintenance, watering and waiting for those vegies to
come up. You will love the crops of herbicide-free foods.
You’ll wonder why you didn’t start earlier!
lives in Gippsland in Victoria, Australia and specializes
in growing South African bulbs and other species. He
is involved in horticultural training and development
of programs included organic gardening, worm farming,
and bee keeping. He is a member of the International
Bulb Society and have photos and some articles on the
International Bulb Society page. His specialty area
is growing the South African species Ixia.
Soil tests done in a lab
are one way to check the health of your soil. However,
the ultimate test is how well your plants are doing.
By carefully observing your plants, you can tell which
nutrient your plants are lacking. With this information,
you can choose which amendments should be added to the
soil to maximize the soil health.
When adding amendments
to your soil, always start with very small amounts.
Too much of a nutrient is can be worse than too little.
If there is a serious nutrient imbalance, your plants
may be unable to absorb the nutrients they need. Therefore,
your plant may exhibit signs of a nutrient deficiency,
but the problem is an excess of other nutrient. Therefore,
observe your plants closely and if they don’t improve,
go ahead and have a lab check your soil. Excess nutrients
can also pollute our water and soil and waste energy
during manufacturing and distribution. So use soil amendments
The chart below contains
symptoms of major nutrient deficiencies, how these nutrients
function in the plant, and what organic amendments contain
Leaves are uniformly yellow-green
Cucumbers are pointed at the tips
genetic material, hormones, and other chemicals
|Fish, alfalfa, or
blood meal; green manures
Yellow or streaked leaf margins
Leaf tips die off
Fruits late, poor or absent
root growth, storage and use of energy
|Brown leaf margins
on lower leaves
Plants not as healthy
||Aids in nutrient
movement, protein synthesis, and carbohydrate metabolism
dust, Kelp, compost, manure
|Leaves curled upward
Leaves are scalloped
Buds dried out or absent
Buds drop off early while the stem is still stiff
Tomato blossom end rot
||Cell wall manufacture
and regulation, activates several enzymes
clam and oyster lime shell, gypsum, wood ashes
|Leaves at branch
tips turn down
Stems are hard and brittle
||Found in amino acids,
vitamins and co-enzymes
gypsum, elemental sulfur
|Leaves are thin and
brittle; purplish red or brown to bronze; striped
or yellow to brown between veins; curl upward; or
don’t grow long
Plants mature late and don’t thrive
aids in carbohydrate
metabolism, energy use, and genetic material manufacture
|Kelp or fish extract,
mulch dolomitic limestone, compost
|Pale yellow color
between leaf veins
||Part of enzymes,
aids in chlorophyll manufacture
|Iron sulfate, chelated
In the trace element chart
below, I’ve only included what the symptoms of the deficiencies.
I haven’t included what nutrients you can use to fix
the problem. Because trace elements are needed at such
low levels, it is very easy to add too much and seriously
harm your plants. If you suspect a trace element problem,
use compost, rock powders, and kelp to improve the health
of your soil. Your compost should contain ingredients
from outside your immediate vicinity. Clearly, if your
entire property is lacking in zinc, compost made from
your grass and leaves will also be lacking in zinc.
Import manure or compost from a safe source to supplement
your regular compost.
|Leaves are smaller
and have mottled, stripped, or dead areas
Buds have dead tips and margins
Buds drop off the plant early while the stems
are stiff and erect
first on new growth
Leaves are misshapen or curled downward
Buds are pale green
Flowers drop off at higher than normal rate
Decreased stem growth
Beets and turnips have “corklike” areas
Broccoli and cauliflower have a hollow stem
|Pale yellow color
between leaf veins
Brown or gray spots on leaves
Leaves drop off
|Leaves are blanched
Fruit is sour
Cauliflower has reduced or irregular leaves
Citrus fruit has ‘yellow spot’
Bradley, F.M. (Ed). 1991.
Rodale’s Chemical-Free Yard and Garden. Emmaus,
PA: Rodale Press, Inc.
Mikkelson, R. and J. Camberto.
1995. Potassium, Sulfur, Lime and Micronutrient Fertilizers.
in Soil Amendments and Environmental Quality.
J. E. Richcigel (ed) Boca Raton, FL: CRC Press, Inc.
Miller, C. and M.L. Facciola.
1995. Let’s get Growing: a Dirt-under-the-nails
Primer on Raising Vegetables, Fruits, and Flowers Organically.
Emmaus, PA: Rodale Press, Inc.
Schultz, W. 1989. The
Chemical-Free Lawn. Rodale Press, Inc., Emmaus, PA.
is an organic gardener and writer who’s worked with
a variety of environmental groups.
Since the garden is starting to produce lovely spring
greens, we though this recipe from CooksRecipes.com would
- 1/3 cup golden raisins
- 1/3 cup fresh lemon
- 4 tablespoons olive
- 1 medium red onion,
- 4 garlic cloves, minced
- 1 bunch red or green
Swiss chard, stems trimmed, coarsely chopped
- 1 bunch beet greens,
stems trimmed, coarsely chopped
- 2 tablespoons minced
peeled fresh ginger
- 1 1/2 tablespoons grated
- Salt and freshly ground
black pepper to taste
- 1 pound fusilli pasta,
cooked according to package directions
- 5 ounces soft fresh
goat cheese (such as Montrachet)
Combine raisins and
lemon juice in small bowl. Set aside.
Heat 2 tablespoons
oil in large pot over medium-low heat. Add onion
and sauté until softened. Add garlic and sauté about
30 seconds. Add Swiss chard, beet greens and raisin
mixture. Cover and cook, stirring occasionally,
until greens wilt, about 5 minutes.
Stir in ginger and
lemon peel. Season greens to taste with salt and
Toss hot, fresh cooked
pasta with remaining 2 tablespoons olive oil. Add
greens mixture and goat cheese. Toss to combine.
Season to taste with salt and pepper and serve.
Serves 4 to 6.