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Frequently Asked Questions


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Backyard Composting and Vermicomposting

What is the ideal placement and temperature of a worm bin?

Keep worm bins out of direct sunlight. Even if the bin is kept in a shaded area, it should be moved to a more temperate location if the temperature exceeds 90 degrees Fahrenheit. They can be kept indoors or outdoors and can be placed directly on the ground or raised above ground.

How can I keep animals away from my backyard compost bin?

Animals are typically attracted to compost bins when they smell food. Avoid putting in meat, dairy, processed foods or other food waste that is not suited to this type of composting system. Bury fresh food scraps and top with a layer of browns/carbon such as dried leaves, cardboard or straw. If your bin is placed on soft or uneven ground and you are concerned about rodents digging in through the bottom, you can line the bottom of the bin with hardware cloth, a metal mesh that can be purchased at home improvement stores.

What should I do with worm leachate?

Worm leachate is the liquid by product of worm composting that collects in the catchment basin at the base of your worm bin. It should be drained and disposed of regularly. Because this is not a composted product, it can contain harmful bacteria and pathogens. For this reason, we recommend that you dilute it to at least two parts water to one-part leachate and use it only to water non-edible plants in the garden. It can also simply be disposed of down the drain undiluted.

How do I make worm tea?

There are different methods of making worm tea, which can be used as liquid fertilizer and spray-on inoculant for all types of plants. The simplest method is to place a scoop of finished worm castings (aka vermicompost) into a porous bag (such as cheesecloth, a tea bag, an old t-shirt, etc.) and soak it in a 5-gallon bucket of water for 24 hours. The worm tea is ready when it turns light brown in color. It can be diluted to 50 percent worm tea and 50 percent water and used to water your plants or sprayed on plants to deter pests and disease.

How can I keep houseflies and maggots out of the compost bin?

Compost bins are often home to certain insects and their larvae. Black soldier fly larvae are common and an excellent composting critter. However, houseflies can carry disease, so they should be kept out of your compost bin. As long as your backyard bin is heating up to the appropriate temperature (above 120 degrees Farenheit), houseflies and their larvae will be killed off. Turn the pile on a regular basis to encourage even heating and cover any fresh fruit and vegetable waste with a layer of "browns" to deter flies.

The best way to keep houseflies out of a worm bin is to ensure they do not become trapped when you close the lid; otherwise they shouldn't be able to find their way in.

Which plant materials should be added in moderation to the compost bin?

Most yard waste can be added to your compost bin. A few types of plants can be problematic. Palm frond, for example, can take a very long time to break down into compost. Pine needles also take a long time to break down so should also be added in moderation (note that, while fresh pine needles are acidic, their pH becomes more neutral as they decompose, so acidity is not a major concern). Eucalyptus bark and leaves can be toxic to certain plants when fresh, but the hot composting process renders them harmless. For this reason, eucalyptus should only be added to a hot composting system (as opposed to a worm bin). Invasive weeds that have gone to seed or that spread through the rhizomes in their roots can also be problematic if the contents of your compost bin do not heat up sufficiently to kill off their viability.

Can animal manure be added to my compost bin?

In some cases, yes. The manure of herbivores like horses, rabbits, chickens, goats, quail and tortoises can be added to a backyard compost bin and are a source of nitrogen. Cat and dog waste should never be added to the compost bin. The high nitrogen content in animal manure does contribute to the heating process in the compost pile, so it should be well-balanced with carbon sources. It is not appropriate for worm bins.

How often should I add compost to my garden?

You can add a 2 to 4-inch layer of compost or worm castings onto your soil at the beginning of each planting season and then mix it in to a depth of 6 to 12 inches. For perennials, you can add to the soil around established plants twice a year and dig in gently without disturbing the plants roots. For plants that appear to be deficient in nutrients or that appreciate more frequent fertilization, you can add more often.

Can onions and garlic go in the worm bin?

Yes, added in moderation, onions and garlic do not bother worms. They may generate an odor before they are consumed, but that is the only real contraindication to adding them to a worm bin.

Can citrus go in the worm bin?

Citrus fruits and peels should be kept out of the worm bin, as they can contribute to an overly acidic environment that is bothersome to worms and can attract pests.

Can I add any type of worms to my worm bin? Where can I purchase worms?

The most common species of composting worms are Elsenia Foetida and Lumbricus Rubellis, also known as red worms, red wrigglers, tiger worms, brandling worms and manure worms. Both types are also often used for fish bait and may be available for sale at bait and tackle shops.

Can I put worms in a backyard compost bin?

Yes, but they will need a way to escape the heat of the bin as needed. If your backyard bin is placed over dirt or soil, worms may find their way into it on their own. However, you should not add worms to a compost bin that is placed in direct sunlight and not on top of dirt/soil.

Can I put bread, pasta, rice, etc. in the compost bin?

Yes, as long as they are plain. However, if they have residue of meat, dairy or oil, they should not be placed in the bin. It is always a good idea to bury food scraps under a layer of carbon materials (or "browns") to avoid attracting vermin and pests.

Can I add copy paper with ink to my worm bin?

Copy paper can be placed in the bin. However, synthetic inks can contain chemicals that you do not want to build in your compost and soil. For this reason, it is best to stick to newsprint that is printed in soy-based inks.


Organic Gardening

What is the best way to amend clay soil?

Heavy clay soil is notoriously difficult to work with. The best way to improve the tilth and structure is with regular applications of organic matter, including compost, vermicompost, bark, sawdust, manure, leaf mold and peat moss. Organic amendments will need to be tilled or dug into the top six inches or so of soil and it may take repeated applications to make a difference.

The leaves on my citrus trees are turning yellow; what does that mean?

Yellow leaves can be a sign of overwatering. Young citrus trees typically need deep watering once a week, while well-established trees only need to be deeply watered once a month. If you are watering appropriately, yellowing leaves can be a sign of nitrogen deficiency, which can be corrected with the application of an organic fertilizer suitable for fruit trees.

What is the best way to get rid of ants in the garden?

In many cases, ants are naturally present in large quantities underground. While they can be pesky when they crawl up your arms and legs, they are actually an important part of the soil food web and generally good for the garden. However, if they are becoming a nuisance, some organic treatment methods include applyng food-grade diatomaceous earth to the surface of the soil or baiting them with a mix of borax, cornmeal and honey.

Can I use pressure treated lumber to make raised edible beds?

While there are studies that have shown that chemicals do leach out of wood into soil and are uptaken by plants, there is not much research about whether these quantities are enough to affect human health. To be on the safe side, we don't recommend it.

Can I use 100% compost in place of soil?

While most topsoil is mainly composed of inorganic mineral content and benefits from the addition of compost, it is not advised to try growing a garden in 100 percent compost-compost on its own is not ideal for plant support or water retention and quickly compresses over time as the organic materials continue to break down.


Small-space Gardening

My bokashi bin is smelly; how do I correct this?

It is normal for the contents of your bokashi bin to have a slight sour, pickle-like odor. But if the smell is putrid, that is a sign that something went wrong and you will need to dispose of the contents and start over. You can learn more about bokashi composting with this guide from Sustainable Little Tokyo.

How deeply does fermented bokashi need to be buried in the garden?

Bokashi contents should be mixed with soil in a hole in the garden and buried under two inches of dirt. After two to four weeks, the bokashi mix will have fully decomposed and fertilized the soil for planting.

Can greasy food go in the bokashi bin?

You should avoid putting anything that has excess grease, oil or liquid in your bokashi bin.

How do I address gnats and other insects on my indoor plants?

To discourage fruit flies and fungus gnats on indoor plants, remove any dead or decaying plant matter right away, avoid over watering and always use fresh potting soil. If bugs are still an issue, organic pesticide spray options include insecticidal soap and neem oil.

Can vermicompost be used on indoor plants?

Yes. Vermicompost can be an excellent soil amendment for indoor plants and can be applied every other month (a little goes a long way, so its great for houseplants).

How often do container gardens need to be fertilized?

This will depend on the type of plant and the type of organic fertilizer being applied. Tomatoes, for example, are considered "heavy feeders" and require frequent application in order to yield fruit. Herbs like rosemary, lavender and thyme, on the other hand, do not need to be fertilized at all.

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