October 4, 2002
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Gardening 101 Pests & Disease Propagation Seeds Spring

Seed Starting – Germination

Guest post by Beate Schwirtlich

What Happens When A Seed Germinates?

The whole purpose of starting seeds indoors is to cheat winter a little.

Ironically, even as we cheat nature, we must imitate her. Light, soil, water, air, and a basic understanding of the process of germination are all you need. Once you know the simple things a seed requires, starting them indoors won’t seem half as complicated.

Seeds are their own energy source, a plant in embryo form. They store energy in a form that is released and used only when water, oxygen, soil, and a close-to-ideal temperature are a part of their surroundings.

Until then, they remain dormant. Germination inhibitors are part of the make-up of every seed. They actually prevent a seed from germinating until its chances of survival are good. Usually chemical in nature (five per cent of seeds are simply waterproof, dormant until their seed coat cracks), germination inhibitors put a seed into dormancy. Without these, a tomato seed, for example, would spout right inside the fruit of the plant that formed it, where there is moisture and warmth, good conditions for germination. Inhibitors give a seed time to travel away from the parent plant, and allow it to overwinter, or be stored, giving that seed the best possible chance to reproduce successfully and to spread. Germination inhibitors ‘wear off’ over time, allowing a seed to sprout the next year.

The seed coat or outside of a seed protects it during dormancy. Hidden inside that coat is the radicle or beginning of a root, the hypocotyl or beginning of a shoot, either one or two seed leaves or cotyledons (the seed’s food supply), and the epicotyl, which will become the first true leaves. The seeds of some plants have a second food supply, called the endosperm. Plants with one cotyledon are called monocots. Those with two are dicots.

Spring like conditions soil that’s wet and beginning to warm up, and longer days and stronger sunlight signal the seed to break dormancy. Light triggers germination of many small seeds, while other seeds germinate best in darkness. Some seeds prefer warm temperatures, others cold. Such differences are a reflection of biodiversity. Simply, plants native to areas with warm conditions produce seeds that germinate best in warm soil, while those native to cold places prefer cool soil.

Know what conditions your seeds naturally prefer, and try to emulate them.

Water does two things to a seed. First, it activates enzymes that stimulate the release of food energy stored during dormancy. Second, it splits the tough seed coat open so that oxygen gets in. Energy stored in the cotyledon ‘burns’ and is used only in the presence of oxygen, powering the seedling’s cells as they begin to divide and grow. This process is called respiration.

Soil holds the water and air that a seed needs to respirate. Too much water drives out air pockets in soil. Don’t over-water. Without air, seeds can’t use their stored energy through respiration. Never let seeded soil dry out. Without water, seeds can’t use their stored energy.
This stored energy only lasts so long. That’s why a sprouting seed works so hard to break the soil and unfold into the light quickly. It’s also the reason that germination of many seeds is triggered by light. If a small seed germinated in a moist but dark environment, it might run out of energy before ever reaching the soil surface. But if a seed needs light, it won’t germinate until it’s close to the soil surface. That way, it has a chance to survive. But before a seed begins to grow up, it grows down, anchoring itself with a root, the first life to emerge from the seed coat. The root allows the spout to begin to absorb water and food from the soil.

A seed can only store so much energy. That‘s why smaller seeds must be planted shallower, larger seeds deeper. Little seeds planted too deep will exhaust themselves and die underground. Large seeds can easily dry up if planted too shallow. Really small seeds should just be pressed onto the soil surface.

Next, the shoot begins to grow, splitting the seed coat even more. Soon, the growing shoot pushes the seed leave(s) above the soil. They unfold, sometimes still wearing their dried up seed coat on their tips. As the root continues to grow, a bud will appear between the seed leave(s). From this, the first two true leaves will grow, enabling the plant to begin to photosynthesis, the production of energy using light.

Lacking light, seedlings will compensate by shooting up towards the light source and becoming ‘leggy’ and weak. Provide lots of light twelve hours a day. Use a south-facing windowsill, or good artificial lighting.

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October 4, 2002
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Pests & Disease Seeds

Seed Starting – Damping Off

Guest post by Beate Schwirtlich

Seed Rot or ‘Damping Off’… What is damping off?

This gentle term describes the death of seedlings by fungal disease, either before or after they emerge from the pod. This sudden plant death can happen for up to four weeks after seeds are started. It actually describers a few different fungal diseases carried in soil or seed. These fungi can survive for years or forever in soil, and are found in all soil outdoors.

Causes:

  • overwatering
  • unsterile soil
  • dirty growing containers
  • overcrowding seedlings
  • stress, such as low light, cool temperatures

Symptoms:

  • Seeds don’t germinate: they may have rotted underground
  • Sudden wilting or discolouration
  • seedling falls over: stem bends at soil level
  • roots of diseased plant are black or brown

Prevention:

  • Clean growing conditions.
  • Clean containers yearly
  • use sterile soil mixes.
  • Water seedlings from the bottom of their containers
  • Avoid overwatering
  • Don’t plant seeds too deep
  • Soil with a low pH: commercial starter mixes average 5.5 pH
  • Good ventilation: moving air
  • Use a soil-less starting mix, such as a peat moss/vermiculite mix. (This is not an environmentally friendly option, however, as peat moss is comes from sensitive bogs.)
  • Plant seeds on soil, but cover with sand instead of soil.

Protect seedlings organically:

  • Mist plants with either chamomile clove, or stinging nettle tea as a preventative. These herbal brews have known anti-fungal properties.
  • A one-time dusting of cinnamon powder or powdered charcoal on the soil surface will also help prevent damping-off.
  • Disinfect containers and tools with very hot water and biodegradable soap: this is the most environmentally conscious method. If you think you have a real problem with damping off, use one part bleach to four parts water, or a 70% solution of rubbing alcohol.

Confession of a lazy grower
I do only two things to prevent damping off: I avoid overwatering, and I provide good air circulation. My seedlings are doing fine.

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September 5, 2002
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Foraging Pests & Disease Projects

Weeds in Your Garden — Bite Back!

By Susun Weed

I always say the gardener’s best revenge is to eat the weeds. I’ve been doing it for thirty years and can testify that my health and the health of my garden has never been better. Here are a few hints for gardeners who’d rather eat their weeds than hate them (and for non-gardeners who are adventurous enough to try out nature’s bounty).

View your weeds as cultivated plants; give them the same care and you’ll reap a tremendous harvest. Harvest frequently and do it when the weeds are young and tender. Thin your weeds and pinch back the annuals so your weeds become lushly leafy. Use weeds as rotation crops; they bring up subsoil minerals and protect against many insects. “Interplant” (by not weeding out) selected weeds; try purslane, lamb’s quarters, or amaranth with your corn, chickweed with peas/beans, and yellow dock, sheep sorrel, or dandelion with tomatoes). And, most importantly, harvest your weeds frequently, regularly, and generously.

Overgrown radishes, lettuces, and beans are tough and bitter. So are weeds that aren’t harvested frequently enough. Give your chickweed a haircut (yes! with scissors) every 4-7 days and it will stay tender all spring, ready to be added to any salad. If you forget a patch for two weeks, it may get stringy and tough and full of seed capsules. (All is not lost at this stage. The seeds are easy to collect—put the entire plant in a plastic bag in the refrigerator for 2-3 days and use the seeds that fall to the bottom of the bag—and highly nutritious, with exceptional amounts of protein and minerals.

Unthinned carrots and lettuces grow thin and spindly, so do unthinned lamb’s quarters, amaranth, and other edible weeds. Wherever you decide to let the weeds grow, keep them thinned as you would any plant you expect to eat. Here’s how I do it: In early spring I lightly top-dress a raised bed with my cool-method compost (which is loaded with the seeds of edible weeds). Over this I strew a heavy coating of the seeds of lettuces and cresses and brassicas (cultivated salad greens), then another light covering of shifted compost.

Naturally, weed seeds germinate right along with my salad greens. When the plant are about two inches high, I go through the bed and thin the salad greens, pull out all grasses, smartweeds, cronewort, clear weed, and quick weed (though the last three are edible, I don’t find them particularly palatable). And, I thin back the chickweed, mallows, lamb’s quarters, amaranth, and garlic mustard and other edible wild greens.

Keep those annuals pinched back. You wouldn’t let your basil go straight up and go to flower, don’t let your lamb’s quarter either. One cultivated lamb’s quarter plant in my garden grew five feet high and four feet across, providing greens for salads and cooking all summer and a generous harvest of seeds for winter use.

When a crop of greens has bolted or gone to seed in your garden, you pull it all out and replant with another crop. Do the same with your weeds. We eat the greens of garlic mustard all spring, then pull it out just before it bolts (making a horseradishy vinegar from the choicest roots) — often revealing a generous crop of chickweed lurking underneath.

Some of My Favorite Garden Weeds

Annuals

Amaranth (Amaranthus retroflexus)
Young leaves, old leaves, even non-woody stalks are delicious as a cooked green; chop and boil for 30-40 minutes. Serve in their own broth; freeze leftovers for winter use. Use instead of spinach in quiche (you may never to grow spinach again). Collect seeds throughout the autumn by shaking seed heads over a lipped cookie sheet; or by harvest and dry the entire seed head. Winnowing out the chaff is tedious but soothing. There is a special thrill that comes when you toss the chaffy seed in the air, and the breeze catches it just-so, and the seeds fall back into your tray, while the prickly chaff scatters “to the four winds.”

Chickweed (Stellaria media)
Young leaves and stalks, even flowers, in salads. Blend with virgin olive oil and organic garlic for an unforgettable pesto. Add seeds to porridge.

Lamb’s Quarter (Chenopodium alba and related species, e.g. Chenopodium quinoa)
Young leaves in salads. Older leaves and tender stalks cooked. Leaves dried and ground into flour (replaces up to half the flour in any recipe). Seeds dried and cooked in soups, porridge.

Mallows (Malva neglecta and related species)
Leaves of any age and flowers (the closely related Hibiscus flowers too!) are delicious in salads. Roots are used medicinally.

Purslane (Portulacca oleracea)
The fleshy leaves and stalks of this plant are incredibly delicious in salads and not bad at all preserved in vinegar for winter use.

Biennials

Burdock (Arctium lappa)
Roots of non-flowering plants harvested after frost make a vinegar that is deep, and richly flavorful as well as a world-renowned tonic. Petioles of the leaves and the flowering stalk are also edible.

Garlic Mustard (Alliaria officinalis)
Year-round salad green. Leaves used in any season, even winter. Roots are harvested before plant flowers. Seeds are a spicy condiment.

Queen Anne’s Lace (Daucus carota)
Leaves finely chopped in salads. Flowers are beautiful edible decorations. Roots of non-flowering plants, harvested in the fall, and cooked.

Perennials

Dandelion (Taraxacum officinalis)
Leaves eaten at any time, raw or cooked, but especially tasty in the fall ? not spring! Roots harvested any time; pickle in apple cider vinegar for winter use. Dandelion flower wine is justly famous.

Sheep Sorrel (Rumex acetosella)
Leaves add a sour spark to salads. Cooked with wild leeks or cultivated onion and potato they become a soup called “schav.”

Stinging Nettle (Urtica dioica)
Young leaves cooked for 40-45 minutes and served in their broth are one of my favorite dishes. Seeds can be used in baked goods, porridge.

Yellow Dock (Rumex crispus) Roots pickled in apple cider vinegar are tasty and a boon for enriching the blood. Leaves, especially young ones, are eaten raw or cooked.

Susun Weed, green witch and wise woman, is an extraordinary teacher with a joyous spirit, a powerful presence, and an encyclopedic knowledge of herbs and health. Ms. Weed’s four herbal medicine books focus on women’s health topics including: menopause, childbearing, and breast health. For more please visit www.susunweed.com.

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June 8, 2001
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Pests & Disease

Weed and Herbicide Free

Guest post by Nadia Gard(e)ner

Prevent the pollution of our water, soil and ultimately, animals (like us).

With summer our precious plants have returned, and with them the wicked weeds also arise. While some may be tempted by the seemingly simple solution, herbicides, their environmental effects outweigh any benefit. Herbicides are chemicals used to kill weeds in agriculture as well as household gardens. Many herbicides currently on the market are selective: meaning they kill only specific weeds. However, this does not make them any safer than the non-specific types that kill virtually every plant in their path.

Herbicides are toxic to most mammals (that means you, me, your dog, and your kids) as well as to the beneficial insects that you want to encourage in your garden to keep away harmful pests. Sometimes herbicides seep into the ground water; causing contamination of which the long term effects are not known.

Recent polls have shown that US residents see pollution as the result of boardroom decisions of large companies. In fact, agriculture is the top non-source polluter nationwide. Household chemical use also has a significant impact.

Phasing out the use of chemical herbicides at home can make a significant impact on our pollution problem.

Non-Toxic Weed Control

Herbicides are marketed as quick and easy solutions to weed problems. However, their use does not fix the problem, it only stalls the weeds for a time. If they are used as the sole “solution”, they will need to be used again and again. Preventative methods are a better solution. Weeds need a certain environment to thrive. If that environment is uncomfortable for them, they will be less likely to grow. Working from this simple premise not only saves time and money, but also prevents dangerous chemicals from being released into our environment.

Weed control can be a daunting task. However, with regular maintenance and a few preventative tools, weeding can be manageable, even easy.

  • During the growing season, make a commitment to weed 20 minutes every week. Grab a hoe and disturb the little guys before they have the opportunity to grow big and tough. Circle hoes and asparagus knives/weeders are great weeding investments.
  • Mulch, mulch, mulch! Weed bare earth thoroughly and place 3 inches or more of wood chips, grass clippings, straw, and/ or leaves over it. This will also help your plants conserve water and provide them nutrients. For pathways and other unplanted spots, place black landscaping cloth (or newspapers) under the mulch.
  • Plant beds closely and evenly, leaving little room for weeds to grow. As your plants grow, they will crowd weeds out as they drink all water and shade the bare ground.
  • Do not let weeds set seed. If nothing else, clip those weed flowers and seed heads as you see them.
  • For concrete cracks, kill weeds with a good clipping and boiling water.
  • In the off-season, use cover crops or mulch to prevent weed growth.
  • Rotate crops from year to year. Weeds hate that, as do pests.
  • Your weeds make a great addition to a hot compost pile. However, if your compost pile is not regularly maintained, i.e. turned and watered, keep out seeds and invasive weed roots.

Environmentally Safe Weed Prevention Products

If you choose to use herbicides, consider non-toxic alternatives. Several companies have come out with more environmentally sound herbicides, including: Bioganic and Safer. Corn gluten spread on bare earth has been shown to prevent weed growth. A handful of companies are providing gluten products. If your local nurseries do not carry these items, the Internet is a good resource.

Homemade Herbicides

  • Vinegar and salt is great for places where you won’t be growing anything in the near future. Spray directly on plants.
  • To remove young plants, pour boiling water directly on them. This is the simplest, yet safest herbicide there is. Just be careful to avoid plants that you don’t want to damage.
  • Pour Coca-Cola on the cracks in the sidewalk to kill weeds. It’s sticky, but within a week the weeds will be dead.
  • Spray some Gin mixed with a bit of apple cider vinegar and water on your weeds being careful to avoid other plants.
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May 30, 2001
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Fauna Pests & Disease

Good Bugs, Bad Bugs: Mite vs. Mite

Guest post by Arzeena Hamir

Predatory Mite

The predatory mite, Phytoseiulus persimilis, is a welcome insect in the garden and greenhouse. It is a fast moving insect with an orange teardrop-shaped body. The species is a specialized predator of the two-spotted spider mite and feeds on all stages of its prey, from egg to adult. The adult P. persimilis is a voracious eater, eating between 5 and 20 prey per day. It uses its sense of smell to find plants infected by spider mites. As soon as it comes into contact with spider mite webbing, it will intensify its search.

P. persimilis can be purchased from many biological control companies. It is often shipped in a glass vial or on trays of bean leaves. The easiest methodof application is to sprinkle about 20 adults on each plant. These predatory mites prefer to work their way up a plant, searching for food, so try to introduce them as low down as possible. In addition, if many plants are infected, keep them close together with their leaves touching so that these predators will be able to easily move from one plant to another.

Unlike the spider mite, P. persimilis prefers humid conditions. Misting will not only help it multiply, but will keep the spider mite population down as well. A relative humidity of 70 per cent is ideal for P. persimilis. Once its food supply is exhausted, the numbers of P. persimilis will decline as well.

Two-Spotted Spider Mite

Spider mites, also known as two-spotted mites, become a particular problem for the gardener through the winter. Normally, they hibernate in ground litter or under the bark of trees or shrubs. However, if they stowaway onto a plant being brought indoors, the artificial lights, and warm, dry, conditions of most heated homes will allow them to keep infecting plants.

The spider mite, Tetranychus urticae, is a tiny, 8-legged pest related to the spider & tick. Adults are normally green or yellow but turn red when day lengths shorten in the autumn. They attack plants by stabbing the underside of the leaves and sucking out the sap. This damage causes a distinctive stippling effect due to the loss of chlorophyll. As their numbers increase, the number of white speckles on the leaf increases and the leaf eventually dies. Once the spider mites begin reproduction, a distinctive `webbing’ forms, usually under the leaf and then at the growing tip of the plant.

What makes this pest truly difficult to control is its rate of reproduction. Each female will lay up to 12 eggs per day. Mating is not required for egg production. At 21°C, these eggs will hatch in as few as three days and will develop into adults in only 14 days. If left unchecked, 10 spider mites in May will become 100,000 by July!

Spider mites have been found in greenhouses across North America and Europe and are known to attack over 200 species of plants including azalea, camellia, citrus, evergreens, hollies, ligustrum, pittosporum, pyracantha, rose, and viburnum; fruit crops such as blackberries, blueberries and strawberries; vegetables including tomatoes, squash, eggplant, cucumber; and trees such as maple, elm, ash, black locust, and poplar.

Misting plants at least twice a day will keep spider mite numbers down. Populations can also be reduced by spraying the underside of the leaves with a jet of water to break up the webs and wash the mites off. Soap sprays are also very effective at controlling spider mites. The active ingredient, potassium or sodium salts of fatty acids, is not toxic and can safely be used indoors. A homemade spray can also be prepared using ordinary dishwashing detergent. Mix 5 tablespoons of detergent in 1 gallon of water and spray the plants, especially the underside of the leaves.

Resources
Cornell University Biological Control A guide to P. persimilis, the predatory mite

Illustrations by Davin Risk

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