Have a Tea Party with Your Veggies!

Here is an interesting way to use your compost in a foliar application: compost tea. Many gardeners swear by its affects in perking up their plants!

What is Compost Tea?

Compost tea is a small amount of compost steeped for a short time in water, much like brewing tea from tea bags. The result is a rich solution containing both beneficial organisms and nutrients that you use when watering or to spray on leaves.

What are the Benefits of Compost Tea?

I originally thought the benefit of compost tea was simply as an organic replacement for water-soluble fertilizers like Miracle Gro or Peter's Plant Food. It turns out that compost tea is actually much more than a mild fertilizer. It also helps inoculate your plants against disease by introducing beneficial bacteria and fungi to the soil or leaves. The process of making compost tea creates an environment where beneficial organisms flourish at the expense of harmful ones.

Bacteria and fungi are very important in the soil, helping roots absorb water and nutrients. These organisms are also important when present on leaves. Spraying plants with compost tea helps control various mildews, molds, blights, and wilt diseases. The theory is that the beneficial organisms compete with the bad ones for food and space. They may even actively kill harmful organisms by eating them or creating natural antibiotics.

How Do I Make Compost Tea?

Compost tea is relatively easy to make from finished compost. Simply fill a 5-gallon bucket about 3/4 full with room temperature, chlorine-free water (either let tap water sit out for a day, use rainwater, or dip some water from a pond or stream.) Then add one shovel-full of fresh compost and stir. You can also use cheesecloth or another loose fabric to hold the compost as you steep it.

Let the mixture sit overnight (stir it occasionally if you're around). When you return, strain the top half of the liquid through a screen or cloth and spray it on plant leaves or water with it. You must use the tea soon after brewing it; otherwise oxygen in the water will be depleted and the beneficial organisms will die or go dormant.

Oxygen-loving (or aerobic) bacteria and fungi are generally helpful. Anaerobic organisms (those that can live with no oxygen) are usually not beneficial, can cause disease, and just plain stink! If you can't use your tea within 12-18 hours after starting it, you will need to aerate it to add oxygen. You can do that with an electric sump pump to circulate the liquid, or better yet by pumping in air. You can use a regular aquarium air pump to oxygenate the tea.

If you aerate your tea, you'll get the best results if you use it within 1-3 days. If you need to keep your tea for longer than that, add a cup of un-sulfured molasses (or other sugar source) every few days to make sure there's enough food to satisfy your growing colony of beneficial organisms.

After using your compost tea, add the remaining solids back to your compost pile, or mix it into the soil.

Never use bad-smelling compost tea. That's a sure sign there are too many nasty anaerobic organisms lurking in it. If your tea smells like sewage, aerate it for a day or two until the smell goes away. (However, you can use your tea if it simply smells yeasty. Foam that may form on top of your tea is not bad for your plants either.)

More Reading

Here are some compost tea resources and recipes on the web.

Compost Tea Basics at GardenWeb

Compost Teas for Plant Disease Control at ATTRA

Brewing Compost Tea by Elaine Ingham

Compost Tea at PA EPA

Compost Tea by Doug Green


Copyright © 2003 Brian Ballard. All rights reserved.

Dealing With Garden Debris

Every autumn, you begin harvesting bumper crops of vegetables! With that harvest, you'll have lots of extra plant material to get rid of. Here are some helpful tips on what you can do with your green debris.

The best way to get rid of your extra plant material is to chop it and return it to the soil, either by burying it directly in your garden beds or by starting a compost bin. You can also lay the chopped material between rows of plants, or dry it in your paths.

Some plant leaves can simply be shredded by hand. Stems and vines can be cut up with a pair of small clippers. Larger items or heavy stems can be chopped. Machetes, sugar cane knives, cleavers, and hedge clippers work fine for chopping. Find the tool that works best for you. Use a scrap of old lumber as a chopping block.

If you have a large volume of debris, why not start a compost pile? Mix your chopped green material with fall leaves that are plentiful around harvest time. You might also donate your chopped greens to a fellow gardener who is making a compost pile.

Copyright © 2003 Brian Ballard. All rights reserved.

When Your Garden Sleeps, It Dreams

This winter it may seem nothing is happening in your garden. Biological activity slows down in the colder months, organisms go dormant or migrate deeper into the soil, cool season weeds like chickweed get their first footholds, and rains wash nutrients and important minerals away. You don’t have to be a helpless observer of this hibernation. Use the winter months to rebuild your soil.

Once your garden is done for the season, clear out the last of your annual plants saving them for compost. Reserve a small part of the garden for your fall and winter greens and for planting garlic cloves in November. Cover the rest of your soil with a nice layer of compost materials about 8-12 inches deep. Be sure to use both “greens” (grass clippings, coffee grounds, fresh chopped plants, composted manure) and “browns” (fall leaves, non-pressure treated sawdust, dry plant material) in the mix.

A variety of amendments help replenish the supply of important minerals. Agricultural lime is a good source of calcium, and dolomite lime also includes magnesium. Calcium helps plants build cell walls. Magnesium is the working ingredient in chlorophyll. Both types of lime help neutralize acidic soil, which is also a side effect of too much rain.

A compound called greensand includes a different mixture of beneficial minerals including potassium, iron, and phosphorus. It’s usually available at better garden centers.

You can even use granite dust to add a wide array of minerals to your soil. If you look closely at granite, you’ll notice it’s made up of thousands of different crystals fused together. Each crystal is essentially a different mineral, including many that plants require in tiny amounts: potassium, calcium, iron, magnesium, phosphorus, manganese, and others. These minerals become more available when ground into gravel, or even into dust, and are broken down further by organisms and naturally occurring weak acids in the soil. Ready sources of granite dust include stone yards, or gravestone monument carvers.

Spread a few handfuls of lime, greensand, or granite dust over your compost mix and work it in a bit. Water the mulch well, and cover it with two layers of burlap. The burlap works as insulation, keeping the soil and sheet mulch slightly warmer than the air, and provides the dark, moist environment soil organisms prefer. Most coffee roasters will gladly give you discarded burlap bags their raw coffee beans are shipped in.

Once or twice during the winter, pull back the burlap and turn your compost mix, covering it again with the burlap when you’re done. In the spring, you should be able to remove the burlap and either plant directly into the finished compost, or work it into your soil a bit if it’s not completely done.

Copyright © 2006 Brian Ballard. All rights reserved.

What Not to Compost

As easy as composting with nitrogen-rich "greens" and carbon-rich "browns" can be, there are some things you don't want in your compost. Most ingredients you can collect locally are perfectly safe, but knowing some minor details will help prevent a batch of contaminated material from ruining your garden.

Popular "greens" include grass clippings, coffee grounds, herbivorous animal manure, kitchen scraps, freshly pulled weeds and other plant debris.

Scraps or grounds from just about anything a person would eat or drink can be composted without worry. However, don't try to compost meat, dairy products or very oily foods (like shortening). They won't break down in the regular gardener's compost.

If you collect grass clippings from your own or a neighbor's yard, be sure no weed killers, pesticides, weed-n-feed type fertilizers or other herbicides were used on the lawn in the past year. Clippings from lawns treated with a basic N-P-K or even iron-based moss control fertilizers are fine, even if they're not organic. (But don't use moss control lawn fertilizers directly on your garden.)

If you want to compost animal manure, be sure to only use manure from animals that eat plants, like cows, chickens, horses and rabbits. Be sure the animals weren't treated with hormones or antibiotics, which can really disrupt the life cycle of soil organisms. Don't use manure from meat-eating animals like cats, dogs or humans. Feces from carnivorous animals can contain dangerous bacteria, parasites, and even viruses.

If you make a hot compost pile that heats up to 140-160 degrees F, you can compost most weed seeds. But if you make cold compost, avoid weeds that have gone to seed. You should also avoid any plants infected with blight, fungal wilt, club root, viruses or other diseases. Throw those plants away in your regular household trash.

If you live near a lake, you may have thought about composting that pesky, feathery water weed milfoil (Myriophyllum sp.). However, studies show that milfoil is good at sucking up toxic heavy metals; something you don't want in your garden.

Easy to find "browns" include fall leaves, sawdust, paper or straw bales. If you compost sawdust, be sure it didn't come from pressure treated wood, a manufactured wood product (like oriented strand board, particle board, etc.), or from wood that had finishes like paint, deck stain or lacquer applied.

You may have heard rumors that hickory leaves are bad for compost, or that oak leaves make compost too acid, but don't believe them. You can even use a shovel-full or two of wood ashes (but not barbeque or coal ashes) in your compost.

Most newspaper, office paper, cardboard, and junk mail can be composted, but don't compost glossy magazines. Remember that paper is very dry, so be sure to dampen it well when adding it to your compost.

In the fall and winter you can generally find bales of straw that are tempting to use in compost or as winter mulch. However, Washington has historically had a problem with a persistent herbicide called clopyralid (klow-PEER-uh-lid). Many farmers use clopyralid on hay, grains and other crops to kill weeds, but it remains in the soil, passes through grazing animals, and survives even the hot composting process. It will then frizzle your broadleaf plants. If you are offered bales of hay or straw, be sure to ask if there's any chance clopyralid was used before you accept them.

Copyright © 2005 Brian Ballard. All rights reserved.

Save Browns for Spring Composting

Just as Seattle gets too much water in winter and not enough in summer, compost materials can be difficult to balance across the seasons. Spring brings us too many "greens" while fall brings us too many "browns" for a balanced compost pile. The solution is to save some browns now to use next year's compost. Unlike "greens" which tend to get stinky if you try to store them, browns will patiently wait until you're ready for them.

When autumn leaves start falling, offer to rake your neighbor's lawn, or collect leaves from local side streets. Get your kids or grandkids into the act! Collecting leaves will be less messy if you get a head start on the rains, but even wet leaves will store fairly well.

If you have an out of the way location that won't be unsightly, store your leaves in plastic garbage bags. If not, simply pile the leaves on your garden plot after harvest time. Cover the pile with burlap weighted down with stones to keep your leaves from blowing away. You could even build a wire cage at your plot to store more leaves.

Some P-Patches make arrangements with the city to deliver leaves cleared from public streets or parks. If your P-Patch has enough room to store lots of extra leaves, contact the P-Patch office about setting up delivery.

When spring finally rolls around, mix your saved leaves with fresh grass clippings, coffee grounds, and other "greens" to start a batch of compost. If you keep the leaves a year or more, they'll eventually break down into great "leaf mold" that you can use to start seedlings or to mulch your garden. Don't let the word "mold" scare you – that's just the term for old leaves that have broken down to the consistency of soil.

Copyright © 2004 Brian Ballard. All rights reserved.

Preparing Your Garden for Winter

In a few months, you'll be putting your beds to bed for the winter. But that doesn't mean nothing happens during our dark, rainy months. Left bare and exposed to the elements, important nutrients will wash away, and soil organisms will go dormant or even freeze to death.

There are many ways to over-winter your garden while at the same time improving the soil for a head start next spring. Here are three suggestions that you may want to try (or even try each suggestion in a 3-year cycle.)

A Variation on Sheet Composting: Interbay Mulch

Once your beds are cleared of this season's crops, create a mix of equal parts "greens" (grass clippings, coffee grounds, fresh chopped plants, composted manure) and "browns" (fall leaves, non-pressure treated sawdust, dry plant material, etc.) just like you would for a normal compost pile.

Spread your mix in a good 12-18 inch layer on your planting beds. Wet down the mixture well and then cover it all with a layer or two of burlap bags. The burlap keeps the mulch dark, damp and insulated so organisms can work all the way to the top of your compost material. You can pick up free burlap bags on Wednesdays and Fridays at the Tully's loading dock at the south end of their building on Airport Way (the old Rainier brewery).

This winter, check your mulch every few weeks to be sure it's still slightly damp (and that rodents aren't using it as a home). Turn the mulch once on a rare sunny January day to help even out decomposition. By the time spring rolls around, your Interbay Mulch will be finished. A few weeks before you're ready to start planting, remove the burlap and turn your beautifully decomposed mulch into the soil.

Cover Crops

Winter cover crops benefit your soil as they grow and when you turn them under in the spring.

There are basically two types of cover crops: legumes that add nitrogen, and grasses that break up compacted soils and mine minerals from deep down. Nitrogen-fixing plants like crimson clover, vetch, field peas, or fava beans will help capture nitrogen from the air. Cereal rye, winter wheat or other grasses won't capture nitrogen as well as legumes, but their long fibrous roots help break up heavy clay soils. Grasses also mine essential minerals from deep down in the soil where other plant roots don't normally reach. Interplant grasses with legumes to help support the sprawling habit of vetch or field peas.

Plant your winter cover crops now. Better nurseries will a selection of seed mixes. You should even sow cover crops amongst any plants you haven't harvested yet. In May, turn your cover crop under several weeks before you're ready to start spring planting.

Winter Gardening

There are many crops that flourish in the cooler weather of fall, or even prefer a good chilly winter to get a head start on spring. You can start lettuce, arugula, cabbage, mustard, radish, beets, and snow peas now for late fall harvest. Try a cold frame or cloche for continuous harvests of greens through all but the most severe Seattle winter. October is the time to plant garlic or shallots to give their root systems to prepare for spring growth.

Copyright © 2004 Brian Ballard. All rights reserved.

Composting for Beginners

It's easy to make a batch of compost your garden will absolutely love!

Compost is decomposed plant material that helps improve your soil by adding organic matter. It helps soil retain water and provides nutrients in a form plants can use easily. Beneficial fungi and microbes in compost also help your plants absorb water and nutrients from the soil. The process of making compost is actually a speeded-up version of what happens naturally on the forest floor or prairie.

Compost starts with equal portions of "greens" and "browns". Organisms that break down plant material use carbon from browns for energy, and nitrogen from greens as food. Typical greens are: fresh grass clippings, chopped garden debris, coffee grounds or manure. Some browns are: fall leaves, straw, wood chips or sawdust (but don't use chips or sawdust from pressure-treated wood). You should be sure grass clippings come from lawns that were not treated with pesticides or herbicides.

Hot Composting

Hot composting is a method that creates compost very quickly. The bacteria that help break down plant material generate enough heat to raise the temperate to as high as 140-160 degrees. This kills most weed seeds and pathogens. A critical mass of at least 3'x3'x3' is needed to really get the decomposition process going.

To begin a batch, first find or build an empty compost bin. Many P-Patches already have bins just waiting for you! Gather and mix equal parts of greens and browns. Fill your compost bin to the top with this mixture, but don't overfill it and never compress the ingredients to try to make them fit. That squeezes out needed air.

As you transfer your mix to the bin, add enough water to dampen it well, but don't drench it. The fungi, microbes and other critters responsible for decomposition need water and oxygen to live. Too much water pushes out all the oxygen, leaving you with a smelly mess! If the batch is too dry, the composting process will slow down or stop. Your compost should be about as damp as a wrung-out sponge.

Cover the top of your batch with a few burlap bags to help retain moisture. Also cover the bin with a piece of plywood to keep out rain and sun.

Tending your Compost

After a few days your new batch of compost will heat up as bacteria start munching away at plant material, consuming oxygen in the process. Fungi will also feast on the fresh mix. These microbes and critters need air to do their work. About once a week, add more oxygen by turning your pile into an empty bin, or if you only have one bin, remove the contents and then put them back in. Try to move the stuff from the top to the bottom, and vice versa. As you turn, add a little water if the mix appears too dry.

Your batch will seem to shrink as the ingredients settle and rot. I like to top off the bin with more fresh mix the first few times I turn a batch.

Your hot compost is finished when it has mostly stopped decomposing, does not heat up between turnings, and looks and smells like dark soil. The initial ingredients should be unrecognizable in the finished product. In summertime, a batch takes about 6 weeks to finish. In winter, it may take as many as 12 weeks. So plan ahead for planting or transplanting time.

As you might have imagined, collecting ingredients for hot compost all at once, then turning the whole batch every week for 6-12 weeks can be tedious and backbreaking work. There's got to be an easier way -- and there is! It's known as cold composting.

Cold Compost

Any dead plant material will eventually rot back to soil. It may take weeks, months, or even years. The only question is how long you're willing to wait, and how much effort you're willing to add to speed up the process. The process where you add plant material as it becomes available (rather than all at once) is called cold composting because the ingredients don't heat up.

You don't need a bin for cold compost -- you can start a pile in a corner of your garden. As you have plant material to get rid of, just add it to the top of the pile. You can chop material by hand, or just throw it on whole. If you find that you have a lot of fresh plant material to add at once, it wouldn't hurt to add some extra browns. The same balance of greens and browns technically still applies to cold compost piles, but you usually don't have so many greens to add at once that restoring the balance becomes a necessity.

Your cold compost will be ready to use in 6 to 12 months. To get to the good stuff, remove the top layer of material that hasn't decomposed yet. Use that un-rotted material as the base for your next cold pile.

Since cold compost doesn't heat up to kill diseases, seeds and rootstock, you will need to be a little more careful about what you put in a cold pile. Don't add weeds that have gone to seed, diseased plant material, persistent roots from berries or vines, or vegetables like tomatoes or potatoes that may sprout in the wrong places.

Trench or Pit Composting

If you don't have a compost bin handy, or don't have room for a cold compost pile, why not try composting underground?

In trench or pit composting, ingredients are buried in holes or a long trench and covered with soil. When you anticipate you will have lots of garden debris to get rid of (like at harvest time), dig a round hole or a long trench between planting rows about 8-12" deep. As you accumulate green material, chop it and mix it with some browns like fall leaves. Drop the mix into your holes or trenches until they're about half filled, then cover it with the original soil you dug out.

It's important not to bury the plant material too deeply since most biological activity occurs in the top 12" of soil. Some gardeners recommend rotating your open and cooking trenches with plantings in a 3-year cycle. However, each pit or trench should be ready to plant over in a few months. If you wish to plant sooner, try peas or beans since they have shallow roots that won't be damaged by the rotting process happening deeper down, and because they help trap nitrogen that might otherwise escape from the decomposing material.

Sheet Composting

Sheet composting is easier than trench composting because there's no digging involved.

Start your sheet compost with a mix of equal parts greens and browns. I prefer mixing the ingredients thoroughly, but you can use several 2-3" layers of greens and browns if that's easier for you. Spread your mixture in an 8-12" overall layer and water it down. You can cover the mixture with burlap bags and wait a few weeks for decomposition to begin, or you can plant directly in the new mix. The layer of materials won't be thick enough to retain heat, so seeds or roots won't be damaged. You can also plant a cover crop over the compost materials. Nitrogen-fixing covers like crimson clover, vetch, or fava beans are the best since they will help capture nitrogen released in the decomposition process. Rye or other grasses won't capture the nitrogen as well as legumes will.

Using Your Compost

Compost acts as a slow-release fertilizer and you can add it to your garden at any time. Before planting in spring, dig lots of finished compost into the soil. As plants grow throughout the summer, mulch between rows with it every few weeks (but leave a little space around plant stems). In the fall, add compost before sowing a cover crop. If you cover your beds in the winter, add compost to let it age well before spring returns.

Copyright © 2004 Brian Ballard. All rights reserved.