Creating Compost: Garden Gold

ne of the best ways to improve soil is to use compost. Indeed, it may be all you need for a great garden. In a nutshell, compost is simply decomposed organic matter, and composting is the natural process of recycling organic material like kitchen vegetable scraps and garden clippings into this rich soil amendment, affectionately dubbed “black gold” by many a gardener.

Compost helps soil retain moisture and enriches the soil food web, those magical microscopic bacteria, fungi, worms, and other organisms we discussed on previous pages. What’s more, studies show that it can even help plants resist disease and boost their flavor and nutrient content.

While you can purchase compost, it’s easy and fun to make your own. Plus, doing it yourself will save you money as well as reduce the volume of waste you and your family produce. You will probably find that composting changes your mind about your home and landscape: What you once saw as trash (leaves, fallen tree limbs, vegetable peels, even waste paper and cardboard) can be turned into treasure and help make your plot of land a healthy, vibrant ecosystem.

Spring is an ideal time to start composting, as this is when you’re most likely to make plans for and plant your garden. Contents in compost also break down more easily in warm weather.

PILE OR BIN?

To begin, determine which composting method is right for you: pile or bin. Personally, I prefer a goodsized compost pile to any of the bins or other specially crafted containers available, primarily because I find that it’s more convenient to manage than those options when adjustments need to be made (more on that in a minute). But if you have a no-compost-heap city ordinance to contend with, are short on space or are cultivating only a small plot, or are worried about pets or wild critters getting into a pile, a bin might be the better bet.

First steps for a compost pile: Find a sheltered spot in your backyard with enough space to accommodate the amount of material you need to process. Then, gather a few composting tools. I suggest purchasing a good compost thermometer (one with at least a 20- to 24-inch stem). Invest in a strong, sturdy shovel if you don’t already have one to “turn,” or aerate, your pile. Every pile needs a periodic influx of oxygen to speed decomposition. Some people like pitchforks for this task; you can also purchase specialized compost-turner and aerator gadgets. You may need a tarp as well—one that can cover the entirety of your pile, to keep it moist in dry climates or dry in rainy ones—and you might want to fence off the area around your pile if you have dogs or other animals that could make a mess digging for what they see as treats.

First steps for a compost bin: A variety of compost bins can be found for sale online and at garden centers. You can even make your own using a metal or plastic garbage can. Simply puncture several holes in the sides and bottom of the can to provide plenty of air circulation. For additional ventilation, you can raise the can off the ground with bricks or concrete blocks. When it comes time to turn your compost, simply place the can on its side and roll it around. You can also purchase compost tumbler bins. These have tightfitting lids and spin on an axis, which aerates the compost. No matter whether you choose a pile or a bin, it’s often wise to maintain two compost areas side by side— one to receive fresh material, and the other to supply aged compost directly to the garden. When the aged material is gone, hang a sign in that location that says “Put Fresh Material Here” and start removing and spreading compost from the other pile or bin.

THE RIGHT MIX…

Pile or bin, you want the right mix of matter in your compost. You may have to play with and regularly adjust levels to discover the perfect blend, and that’s okay. But generally speaking, you should use roughly even amounts of green waste/nitrogen-rich matter (green leaves and lawn clippings, kitchen produce scraps) and brown waste/ carbon-rich material (wood, paper bags, cardboard, egg shells, dried leaves, branches). If you have access to and are comfortable using manure, you can also add it at around a third green waste, a third brown waste, and a third manure. Cow or horse manure is best. Never use manures from meat-eating animals, as these can harbor parasites that pose a risk to humans.

Many articles online advise having more brown waste than green, closer to a one-third green to two-thirds brown ratio. This makes your compost more fungal, and it is true that many plants prefer this. Yet plants in the Brassicaceae (cabbage) family, including cabbage, broccoli, cauliflower, and Brussels sprouts, like a bacterial mix with more green material.

Why does the mix matter? Too much carbon can cause the pile to break down very slowly, while too much nitrogen can lead to the development of odors. However, the mix never has to be exact, and I want you to enjoy composting as you do all other aspects of gardening. So don’t make it too complicated. If you just add your compost “ingredients” to your pile or bin when you have them, you will eventually get what you want. There’s no need to sweat it too much; experiment and have fun.

When you first mix your pile or turn the compost in your bin, water it well. You want it to be moist but not too wet. The important thing is keeping it oxygenated. If there’s so much water that there are lots of pockets where no oxygen is present, your pile is too wet. If it is too dry, on the other hand, many metabolic processes will be impeded. As mentioned previously, a tarp can help the pile retain moisture in arid climates while keeping too much rain from ruining it in wet locales.

…AND TEMPERATURE

It should take a new compost pile a few days to reach its peak temperature, somewhere between 155 and 165 degrees Fahrenheit. When it gets there, you want to break up its core. Too long at high temperatures will keep metabolic processes so high that oxygen won’t be able to keep up, meaning your pile will go anaerobic (something you don’t want, as this condition can harbor pathogens). When you break up the pile, it cools down. If your pile is not heating up, your mix might be off, your moisture levels might be wrong, or perhaps your manure is too old. A tarp might help a little, or you might just need to go looking for some fresher manure (a fun activity).

Several factors influence how long it takes a pile to break down, including your climate, your mix, and the size of your heap. Over time, the temperature will eventually drop. When it gets close to ambient temperature, or the temperature outside, you have a ready-to-use source of soil and plant food, microbes, and all you really need for a healthy soil ecosystem.

The final color should be a deep, dark brown. Despite the “black gold” nickname, totally black isn’t the goal. If this is the case, then things probably went anaerobic. The pile should smell pleasantly earthy and natural, like a breath of fresh outdoor air while on a nice hike in the woods. It should not smell like an outhouse, ammonia, or rancid food. If it does, again, it probably went anaerobic.

Brewing Compost Tea

Compost tea provides many of the beneficial aspects of compost in an easy-to-use liquid form, convenient for almost any horticultural application. It can be sprayed onto a plant’s leaves, a process called foliar feeding, which boosts nutrient uptake beyond what can be absorbed by the roots. When brewed properly, compost tea can even be a more concentrated source of activated microorganisms than compost itself, as the process helps the microbes “wake up” and multiply. But traditional compost is still valuable, adding carbon to the soil along with other essential soil ingredients. Use the tea in conjunction with compost anywhere in your garden to enliven your soil and convert your dirt into a living biome.

Compost tea brewing is best done in moderate temperatures—spring is an optimal time. Brew it in a shady spot outside following the instructions below. There are also some excellent compost tea brewing kits available online.

Gather your supplies. I suggest using a five-gallon bucket and the best aquarium aerator you can afford. You may also wish to try an aerator specifically designed to make compost tea. They are available online for less than $30: Search for “compost tea aerator.” You will need about three cups of compost, and, depending on whether you want a more bacterial or fungal brew, two tablespoons of non-sulfured molasses (bacterial) or two tablespoons of kelp powder (fungal). Don’t use liquid kelp, as it often contains sulfur or other antifungal agents.

Quick Compost Trick

If you can’t seem to get the perfect mix and your compost needs a push in the right direction, simply ask a neighbor or friend with a productive pile or bin for a little bit of their compost. It will act as an inoculant and stimulate microbial activity.

inoculants from gardening centers or online.

First, put the air pump in the bucket, right in the center of the bottom. The more thoroughly it aerates the entire five gallons, the better. Then fill the bucket with water to within a few inches of the top. If you are using water from a municipal source, aerate with the pump for an hour or so to outgas chlorine, which is harmful to microbial life.

Add your ingredients…then play the waiting game. Add the compost and kelp or molasses to the water. Let the compost tea brew for about 24 hours. Make sure the air pump is secured to the bottom so it doesn’t float to the top overnight. This will keep the tea sufficiently aerobic.

Check and strain. The next day, check your compost tea. It should have a pleasant, fresh and earthy odor. If it smells unpleasant, you’ll want to start over, as it won’t be an ideal brew for your plants. Strain out the compost and immediately apply your tea to the garden, both poured on the soil and sprayed over entire plants.

Clean up. As soon as possible, thoroughly clean your compost tea brewing equipment; things will likely get smelly if you don’t. Clean all corners and surface areas with a gentle natural (not antimicrobial) soap and let dry. Put it away until it’s time to brew your next batch. Don’t use your brewing equipment for anything else.