This first challenge is by Urban Farm Handbook co-author, Joshua McNichols.

Happy roots grow in well-built soil.
Every winter, many gardeners resolve to do things right next season. But when the hustle and bustle of spring comes along, sometimes – well, we run out of time. Maybe we don’t have a place to compost, so all those dried up pea vines at the beginning of summer just end up in the yard waste bin. Maybe we never got around to buying fertilizer, and so raced out to the garden center to buy some. And then we saw the price – yikes! We left the box on the shelf. When weeds overtook the undernourished lettuce, we sighed and conceded to getting our salads from the farmers market this year. We’ve all had moments like these.
It’s not that we don’t know better. As gardeners, we know the importance of compost and fertilizer. Compost mellows the soil, evening out wild fluctuations in water and nutrient availability. When we combine compost with organic fertilizer, our plants are stronger, more nutritious and flavorful. The problem is – when spring finally takes off, when we need a place to compost, when we need quick access to affordable organic fertilizers – we’re just too busy.

Compost
Let’s all plan ahead this year, so we can all have the best gardening season ever. So here’s the challenge: This February, plan for compost now, by dedicating a space in your yard. And buy fertilizer in bulk, or make it from scratch. The first of these challenges will help newbies get over that first hurdle. The second challenge should appeal more to soil building veterans.
Soil Building Challenge 1: Plan for Compost
Find an out of the way corner of the yard for your compost pile. The ideal spot should be accessible by wheelbarrow, so you can haul materials in and out.
After you’ve decided on a spot, build or buy a compost bin. You can get by without an actual bin – your compost can simply be a pile. But there’s something about having an actual bin that helps get us composting. Plus, it keeps things tidy. Whether you intend to keep a loose pile, or a formal bin, for this challenge we want you to get things ready. The goal is this: when you pull that first bucket of garden thinnings from your garden this spring, we want you to have a place to toss them. Without thinking.

My 3-bin compost system. Functional and built to last - but a lot of work to build. If you're new, start with a one bin system, then expand as you get deeper and deeper into it.
While the ideal compost bin has three chambers, you can get by with just one. Three chambers lets you turn the compost more easily from bin to bin. But the goal here is to get you started. Besides, on a small urban lot, you rarely generate enough materials to fill multiple bins.

Really, a compost bin can be anything that will contain the mess.
If you’re inclined to build your own, wooden pallets make a fine and inexpensive building material (use domestic pallets to avoid chemicals).

A simple wire bin
You can build one out of a simple cylinder of chicken wire or hogwire,or you can buy a premanufactured plastic bin. The ideal size is at least a 3 foot cube. That’s big enough for a well-built pile to get hot. And when a pile gets hot – that’s when the whole process of making compost really speeds up!
Of plastic bins, there are many designs, some very expensive. I like those that give you the option of allowing the compost to have contact with the ground – which helps keep things moist. If your material gets dry, it will never break down. That’s why I dislike compost tumblers – they tend to dry out.

Avoid Compost Tumblers

One of the compost bins available from the city of Seattle. You can make one for much less money by drilling a plastic garbage can full of holes. Including the bottom.
If you want to go further, you can also pick up a green cone, which allows you to compost food waste – table scraps for example – without attracting rats. Green cones are very expensive. Seattle used to subsidize them – no longer. Now, I recommend building your own by drilling a small galvanized garbage pail full of holes and burying it 2/3 of the way into the soil. All the holes should be underground.

A green cone just outside my front door. You can build something similar using an old metal garbage pail. Unlike with a compost bin, you don't turn this material - just leave it until it's thoroughly rotted. I have two - I fill one while the other rots.
And finally, you’ll need the right tools. For turning compost, you’ll need a pitchfork. A machete and a log is optional (you can chop large items on top of the log before putting them in the compost, to make things break down faster). And you may want a small wheelbarrow, or even just a bucket for hauling things back and forth.
When you’ve planned a space for compost and assembled the right tools, when you’ll be able to toss the first spring thinnings in there without thinking, post a photo – and we’ll enter you in a drawing to win our modest soil-building prize package. More entry details at the bottom of this post.
Backyard Compost – Something To Be Proud Of
A backyard pile, if well-built (chopped, moistened, aerated, proper mix of greens and browns) will hit at least 150 degrees on the third day, then the temperature will go down. Then you turn it again, bringing material that was on the outside into the hot center. In a few days, it peaks again. You repeat this process over and over again, leaving longer breaks between each turning as the peak temperature gets lower and the process slows down. Though hot composting can destroy seeds and plant diseases, many of them will survive. That’s because even when you mix the pile, not everything gets into the hot center.

Soil health affects plant vigor and nutrition. From The Small Grains by Mark Alfred Carleton, 1916. Older texts like this that predate the ubiquity of chemically-based agriculture offer insight for organic gardeners.
I don’t really expect a backyard pile to consistently kill weeds and pests. To be honest, I don’t care that much about these pests. Our city plot is small enough that dealing with weeds is not a major problem for me ( I just hoe them away), and pests and diseases are only as far away as my neighbor’s yard. Instead, I focus on building up the soil using compost and fertilizer, growing the healthiest plants I can so they can withstand the widest variety of stressors.
There are also advantages to a pile that doesn’t get that hot. The big contractor that composts Seattle’s municipal yardwaste – Cedar Grove Compost – their piles get super hot – about 180. Recognize that temperature from yogurt making? Or from conservative USDA poultry cooking temperature charts? They keep temperatures high by pumping oxygen through the pile using underground pipes. In compost, that kind of heat kills things that are good too.
Commercially produced compost is great for building soil structure. The process is perfect but the product is sterile. Backyard compost is more like a human gut. Alive with competing organisms, some good, some bad. Often, the worst are kept in check by the larger ecosystem of organisms.
So don’t worry too much about the imperfections of backyard compost. The best preventative medicine with plants, as with humans, is good health. And the best way to have healthy plants is to feed them right – using compost and fertilizers.
Okay, end of rant. On with the challenge.
Soil Building Challenge #2: Buy fertilizer in bulk or make it from scratch.
Compost is important, but it can only give your plants those nutrients already found in your soil. Composting recycles those nutrients, and that’s important. But few soils include every nutrient a plant needs – there may be only a couple regions in the world with such soils. And plants grown without enough nutrients will be stunted and more prone to diseases and insect pests. Not only are plants grown in healthy soil more robust, they taste better and offer better nutrition.

The health of your soil MATTERS. From Soil Fertility and Animal Health by William Albrecht, 1958.
Organic fertilizers are best, as they eke out nutrients gradually as they’re digested by micro-organisms in the soil. If you have compost in your soil, the tiny holes and slight negative charge of compost will actually cling tightly to nutrients from fertilizer as they become available. In other words, compost helps keep your fertilizers from being washed out to sea.
That’s important because organic fertilizers are expensive! If you garden in anything larger than a window box, you might want to consider saving some money by buying in bulk. Even if you need just a bit, you can buy in bulk and split it up with friends.
Buy in Bulk
Fertilizer becomes a little more affordable when you purchase it in bulk. What you can buy in your region will vary, but chances are you can get bulk discounts if you order in large enough quantities. For example, around Seattle a 40# bag of Walt’s Rainy Pacific NW Fertilizer is $65.50. But if you band together with 4 friends and purchase 4 bags, you can get them for $49.50 each. If you live in a rainy climate like we do, you’ll probably also need a bag of agricultural or dolomitic lime.

Walt's - where Seattlites can buy organic fertilizers in bulk. Many large cities have similar places catering to urban organic gardeners. If there's nothing like Walt's where you live, you probably have feed stores and can make your own fertilizer. Read on. Image by Google Street View.
Make your own
Fertilizer becomes cheaper still, and better, when you make it yourself. For example, Walt’s blend is simply fish meal, fish bone meal, crab meal, kelp meal and mined gypsum. That’s a good recipe, but not perfect. When I make my own fertilizer, I prefer to use a variant on Steve Solomon’s complete organic fertilizer recipe. It’s formulated for the Pacific Northwest and other somewhat rainy climates (we get 32 inches of rain a year). In desert regions, you’ll want to reduce or eliminate the lime (Rainy weather tends to acidify the soil. Lime counteracts this).

Complete Organic Fertilizer. I store mine in a galvanized garbage can in my garage.
To make Solomon’s recipe, you’ll want to head up to a feed store. Here in Seattle, I make the drive out to DeYoung’s Farm and Garden in Woodinville, one of the closest suburbs where there’s still a remnant of farmland. I suggest going together on this with friends, as most items are sold in large bags, whereas you will only need a little.

Fertilizer matters. From The Small Grains by Carelton, 1916.
Here’s your shopping list.
- (1) 50# bags Alfalfa Seed Meal ($19.98 each) for every two people participating in this purchase. Four participants would be best. You can also use cottonseed meal, but at least in our region, alfalfa meal is much less expensive.
- (1) 35# bag Agricultural Lime 35 lbs ($9.69 each) – you will have leftovers
- (1) 50# bag Gypsum 50 lbs ($16.69 each) – you will have leftovers
- (1) 40# bag Dolomitic Lime ($5.98) – you will have leftovers
- (1) 50# bag Fish Bone Meal ($31.98). In our region, this is cheaper than bone meal. But bone meal, a slaughterhouse byproduct, is also fine to use.
- (1) 50# bag Cal Phos (a substitute for rock phosphate) ($22.98) In other regions, you may be able to find rock phosphate or high phosphate guano, worthy substitutes both.
- 25# of Kelp meal ($35.00) (normally this comes in 50# bags but they’ve sold me 25# quantities in an open paper bag from their bulk supply) – you will have leftovers. You can substitute basalt dust if this is more available in your region.
For all these items, you’ll invest a whopping $122.32 plus $19.98 for every person. That may seem like a lot – until you calculate the cost of the finished fertilizer. I haven’t performed the calculation with precision, but it comes out to less than half the wholesale cost of premixed fertilizer such as Walt’s. If you got together with three other friends, you could use up each and every scrap of Cal Phos and avoid having to store half-empty bags in your garage. You’d pay around $50 each for more than twice as much fertilizer. And this stuff contains a more complete source of nutrients, too.

If you make just a single batch of fertilizer, you're likely to store leftover ingredients in your garage for years. Still, it's much cheaper, and better, than buying premixed fertilizers.
Here’s the recipe, based on Solomon’s. Keep in mind these items may be sold by weight, but our recipe is measured by volume:
- 4 parts alfalfa seed meal
- 1/4 part agricultural lime
- 1/4 part gypsum
- 1/2 part dolomite lime
- 1 part fish bone meal
- 1 part Cal Phos (substitute for rock phosphate)
- 1 part kelp meal
I start by measuring the volume of the alfalfa seed meal. A rare 4 gallon bucket is perfect for this measurement, but you can do it with 1-gallon containers, albeit more slowly. Then, following the recipe above, I add a quart each of the 1/4 part ingredients, 2 quarts of the 1/2 part ingredients and 1 gallon of the 1 part ingredients.
I apply 4-6 quarts of this fertilizer per 100 square feet of garden – every time I plant a new crop. A single batch using one bag of alfalfa meal will last the average urban farmer for years.
Soil Building Challenge #3: Build a Worm Bin
You don’t need tools to do this (although you could build a beautiful wooden one yourself or buy one and the worms from the Seattle Farm Coop). Annette posted directions for making one using plastic storage bins in this post.
Take The Urban Farm Handbook Soil Building Challenge!
Whether you’re a newbie preparing to compost for the first time, a veteran purchasing organic fertilizer in bulk or mixing your own from scratch, or someone who thought worms were just for fishing we want to know about it!
If you have a blog, do a post about it. If you don’t have a blog that’s ok. We’d like everyone to come back to this post when you complete the challenge and let us know what you did, including a link to your blog post if you made one. That way we can see everyone’s project in one place.
Did we mention there will be giveaways?
We’ve got things like rain barrels, Seattle Tilth’s Maritime Guide, an annual membership to Seattle Tilth, red wigglers to get your very own worm bin started, and a copy of the Urban Farm Handbook. So what are you waiting for? Go build some soil already!
Thanks to erix! on flickr for the amazing photo of roots at the top of this post.