Straw bale gardening is an inexpensive, low-maintenance way to grow a bounty of food in a small space. All you need is a bale of straw, some fertilizer, and your favorite vegetable seeds! Craig LeHoullier’s step-by-step instructions show you how to do everything from sourcing the straw and setting up your bale to planting, dealing with weeds and pests, and harvesting.
About the Author
Craig LeHoullier is the author of Growing Vegetables in Straw Bales and Epic Tomatoes and the tomato adviser for Seed Savers Exchange. In the last 30 years, he has trialed more than 1,200 tomato varieties and has introduced more than 100 varieties to the trade. He lectures widely, from local Master Gardener groups to Monticello, the Philadelphia and Northwest Flower Shows, and Seed Savers Exchange.
Read an Excerpt
There's no getting around the fact that gardening is physical work. Although the effort pays off handsomely in fresh, delicious produce, it comes with the unavoidable downsides of a sore back and sweaty clothes. Whether you are turning over the soil in a traditional garden or lugging bags of planting medium for a container garden, you will find it no wonder that gardening is considered good exercise. Happily, straw bale gardening eliminates many of the less enjoyable parts of spring garden preparation. Digging and filling are replaced by simply locating the bales and getting them ready to plant. If that isn't a ringing endorsement of a gardening method, I don't know what is!
How It Works
Here's the simple concept of straw bale gardening: the straw in a bale breaks down over the course of the garden season to provide an effective "home" for the roots of the plants growing in them.
A bale of straw is like a clean, blank slate. It may be mostly free of plant nutrients, but it is also free of diseases. It acts like a sponge, absorbing water and awaiting application of materials that help the straw break down and produce a perfect environment for the roots.
Although some straw bale gardeners report good results by preparing their bales naturally by simply watering them (see Preparing Bales without Fertilizer), my own experience with that method was not as successful. The other basic preparation I recommend consists of regular top additions of high-nitrogen plant food, followed by deep soaking with water. As the straw begins to break down, the process (called bale cooking) generates heat and forms an increasingly absorptive structure that supports healthy root growth. Regular watering and feeding, along with the presence of naturally occurring micronutrients, leads to healthy and vigorous plant growth and high yields of produce.
As you water and fertilize the bale, microbial activity generates heat that moves through the bale and breaks down the straw to provide an ideal habitat for plant roots.
Straw bale gardening offers several advantages over gardening in the ground or in containers:
* You do not need to dig up soil or fill containers.
* The open structure of the bales provides great drainage, so it's difficult to overwater your plants, even in periods of heavy rain.
* The extra elevation of the plant surface lessens your need to bend as you tend and harvest the plants, and may reduce access to some ground-prowling critters.
* You can position your bales in the part of your property that receives the best sun exposure.
Both conventional and organic gardeners can use the technique, with just a few minor variations in bale treatments. Straw bales are a great option for gardeners whose plants have been seriously affected by soil-borne diseases in the past. Spent bales, at the end of the season, consist of great material to work into your traditional garden beds to loosen the structure.
What's Not to Like?
No single gardening approach or technique is perfect, and each — be it traditional in-ground gardens, raised beds, containers, or straw bales — has strengths, weaknesses, and particular challenges. Here are some considerations specific to straw bale gardening:
* The availability and cost of straw bales can vary widely depending on location.
* It may not be easy to confirm that the bales available to you are herbicide-free, and organic gardeners may have concerns about how the straw was grown.
* For optimum success, you have to allow sufficient time to prepare your bales before planting.
* Feeding and watering schedules are critical, particularly during heat waves and as the plants become large and vigorous.
As a bale absorbs water and is colonized by various decomposing organisms, the straw slowly breaks down to provide even more absorbent material at the plant root zone — forming the perfect environment for root crops like potatoes, beets, and carrots. Straw provides lots of structure but little nutritional value to the plant, so timely feeding is important for vigorous growth.
Gathering Your Materials
The checklist of essential materials for growing plants in straw bales is quite brief: the bales, some fertilizer (a high-nitrogen fertilizer and a balanced all-purpose fertilizer), and a planting medium. You will also need an inexpensive digital thermometer, especially for the first time you try the method. Throw in some seeds, sun, water, and a trellis or two, and you're good to go.
Selecting Straw Bales
Straw is simply the remnant of grain crops, after the heads of grain have been removed. The stems are hollow, allowing good absorption of water into the bale (especially if the bale has been oriented with the hollow ends of the straw facing up).
Straw bales are distinct from hay bales, which comprise various forage grasses and include the seed heads as well as the stems. You can grow plants in hay bales, which provide more of a nutritional boost to the plants as they break down, but they often have far more embedded seeds, leading to significant sprouting on the outside of the bales. (Because straw bales are typically harvested after the seed heads are removed, fewer rogue grass seeds sprout throughout the season.) Also, hay bales are not as structurally solid as straw bales and may therefore break down and sag much more quickly.
Straw Bale Types
Before you start looking for a good source, it's important to select the type of straw bale that will work best for your garden.
The types you can choose from will be determined by the region in which you live. Most commercially available straw bales are composed of wheat straw. Oats, rye, barley, and alfalfa also work well for gardening, but bales made up of these types of straw are less commonly available in most places. My suggestion is to either do some research online, such as perusing local Craigslist or newspaper classified ads, or call your local garden centers, farm supply stores, or hardware stores that carry farm and garden supplies. Be sure to confirm that the bales are pesticide-free, in addition to the type of straw.
It is important to avoid using pine straw bales. Pine needles shed water rather than absorb it, break down very slowly, and tend to be acidic. None of these factors will lead to very happy or productive plants.
Straw Bale Sources
You may be surprised by how many sources there are for straw bales. Garden centers may be the first source you think of, but many big-box stores carry straw bales, too. Be sure to call first; I found that even with a specific chain, availability was very different store to store. An even better source, though, is a local farm. To find a farm source, I recommend searching the local Craigslist or newspaper classified ads, starting in the fall, just after harvest is complete.
Whatever source you choose, be aware that straw bales may contain herbicides. Be sure to ask your bale supplier about this. If you are strictly organic, you will need to be choosy about sourcing organically grown straw bales.
Pricing will vary widely according to where you live and what type of straw you want. Also keep in mind that straw bales are quite heavy and large. If you are planning to use significant numbers, seek to have them delivered to you and factor in the delivery cost as you think about prices. If prices seem prohibitive, perhaps other gardeners nearby would like to grow in straw bales, and you can share the delivery cost.
COMMON BALE MATERIALS
Two types of fertilizer are required for straw bale gardening: a high-nitrogen fertilizer to condition the bale, and a balanced fertilizer prior to planting.
Nitrogen is the crucial element in preparing the bale for planting; it speeds the breakdown of the straw to create a good growing environment for the plants. When you check the numbers on fertilizer bags (see Select a Fertilizer), look for a fertilizer with a high first number, which indicates a high amount of nitrogen. For example, many lawn fertilizers are 29-0-4; the high nitrogen content (29 percent) is fine for conditioning your bales.
Prior to planting in the bales you will also need a balanced plant food with equal quantities of nitrogen (N), phosphorus (P), and potassium (K). The balance will provide the nutrients needed for healthy plants and high production. Look for a product with roughly proportional numbers, such as 5-5-5. You will continue applying the balanced food throughout the growing season.
Straw bale gardening works equally well using chemical or organic fertilizers. Chapter 4 gives details about what kinds to buy and how much to use, but following are some of the basic considerations for each.
Fertilizers are labeled with three numbers that indicate the relative weight and percentage of the three major nutrients required for healthy plant growth: nitrogen (N), phosphorus (P), and potassium (K). The numbers, referred to as the NPK ratio, are always given in the same order: N-P-K. For example, a bag of fertilizer that is labeled "5-5-5" contains 5 percent nitrogen, 5 percent of phosphorus, and 5 percent of potassium by weight. (The remaining 85 percent is made up of other nutrients and fillers; the fillers allow the nutrients to be spread evenly over a given area.) Products labeled "1-11" have 1 percent of each of the three nutrients. It is therefore necessary to use 5 cups of 1-1-1 to equal the feeding power of 1 cup of 5-5-5.
As noted above, high-nitrogen lawn fertilizers are fine for straw bale gardening. Besides lawn fertilizers, other high-nitrogen options are urea, ammonium nitrate, and ammonium sulfate. However, when selecting a high-nitrogen chemical fertilizer, be sure not to choose one that is labeled "slow release"; in straw bale gardening the idea is to give the bales a big initial nitrogen kick to get the insides cooking quickly. Also note: It is critical that the product you purchase not contain herbicides. (Many lawn fertilizers do.)
Following the initial high-nitrogen treatment, any inexpensive balanced fertilizer can be used.
Organic high-nitrogen fertilizers include heat-dried microbes, blood meal, and fish emulsion, to name just a few. (See High-Nitrogen Fertilizers for a list of options.) Since the amount of available nitrogen is lower in these versus traditional treatments (in percent of available nitrogen per volume or weight of the material), more needs to be applied.
As for balanced fertilizers, there are plenty of organic products on the market; again, just look for an NPK ratio as close to 1-1-1 as possible.
Once your straw bales are fertilized and ready for planting, you'll need a high-quality soilless mix, with some compost or well-aged manure mixed in to improve moisture retention. You will use this to fill in around the planting holes of prestarted seedlings so that you can anchor the plants and provide some moisture retention early on as the root system develops. If you'll be direct-seeding onto the bales, you'll need to apply a layer of the mix (several inches thick) to the top of the bale. This will provide the seeds with enough moisture to germinate and sustain small roots until they grow long enough to penetrate into the bale.
I recommend avoiding commercial bagged potting soil and using a soilless mix instead. Potting soil is often quite heavy and crusts easily, possibly reducing germination when the bales are direct-seeded.
For organic gardeners, it is important to be aware that many commercial soilless mixes contain traces of chemical fertilizer. If this concerns you, either prepare your own planting medium from materials such as peat moss, fine shredded bark, perlite, or vermiculite, and add some of your own compost. You can also select from among the ever-increasing array of organic planting media at a local garden center.
Purchase an inexpensive, rapid-read digital thermometer (typically found in the grilling section of hardware stores) that has a probe of at least 6 inches long. Taking daily temperature readings of your straw bales during the preparation phase will assure you that the internal structure of the bale is breaking down appropriately, which is signaled by a spike in internal temperature. For the first time straw bale gardener, rising temperatures assure that the preparation is working, while falling temperatures confirm that planting time is near. (See chapter 4 for the optimal temperatures.) It's important to avoid planting into bales when the centers are really cooking, as damage to the roots could result. Once you've become familiar with the effect of the treatments on temperature and timing, the need to take temperature measurements becomes more a matter of interest, not necessity.
Planning for Success
All kinds of gardens benefit from good up-front planning, and straw bale gardens are no different. In particular, it's important to plan enough time to prepare the bales before planting, and to ensure consistent watering. Maintaining a notebook or other type of log is helpful; include lists of needed materials, costs, estimated and actual dates for each part of the process, and observations throughout the season. You will have something to reflect back upon at the end of the journey, and a basis for improvements in the next season.
Select the Best Spot
Whether they're grown in straw bales, in containers, or in the ground, all plants have two basic requirements: sunlight and water. Fortunately, growing vegetables in straw bales allows you a good deal of flexibility. You can place your garden wherever the sun exposure is best, and you can locate the bales so that they're convenient to water. Whether you're watering the bales by hand or with a soaker hose, having easy access to a water spigot will save you time and energy.
Finally, enjoy the freedom from digging holes and avoiding rocky areas. Get out your pencil and paper, and get whimsical with your garden design. Be creative with plant supports. Make a tomato arbor to walk through! Fun, eye-catching straw bale gardens can be a true reflection of your imaginative nature.
Choose the Right Surface
For plants that require staking or trellising, the placement of your straw bale garden will affect the types of supports you can use. If your bale garden is centered on a driveway or patio, you won't be able to drive tall support stakes into the ground; for plants that must be supported, place the bales at the edge of the paved area so that you can drive the supports into the lawn or other piece of unpaved ground. On a deck, you can lash plant stakes to the vertical railing slats; in a yard, you can use fences for support in a similar way.
If you'll be placing the bales on a hard, porous, or absorbent surface such as a wooden deck, consider the effect of constant wetness on that surface. The heavy initial fertilizer treatments, continuous throughout-the-season feeding, and regular watering produces a dark, nutrient-rich runoff that may stain some surfaces. I found that the dark stains washed easily off my concrete driveway, but you may want to consider placing some sort of barrier beneath the bales to protect the surface.
Setting your bales on a flat surface will make them less likely to tilt or tip when the top growth becomes lush and heavy. If the best growing area in your yard is on a slope, you will have to anchor the bales with stakes. Fortunately, though, straw bale gardens on sloped sites are unlikely to experience the kind of soil erosion and washout of young plants and seeds you might see in a typical in-ground garden after a heavy rainfall. Staking is a small price to pay for the ability to utilize a site that you might not otherwise be able to garden on.
Consider using straw bales in a tired garden spot where the soil is nearly spent from years of use. At the end of the season, you can work the structurally broken-down bales into the garden bed, improving the soil structure, adding nutrients, and thereby revitalizing a useful location.
Nobody Likes Weeding
To prevent weeds from growing between and around bales, place your bales on any of the following:
* Hard nonsoil surfaces (wooden deck, concrete or asphalt driveway or patio)
* Landsape fabric (or weed cloth)
* Mulch (loose straw, untreated grass clippings, sheets of plastic)
One option is to cover your garden plot with landscape fabric and position your bales on top. Weeds won't grow between the bales, and any vining plants will have a suitable surface on which to grow.
Consider Your Neighbors
Straw bale gardens look like, well, straw bales with plants growing out of them! As the season progresses and the material within each bale continues to decompose, the bale slowly collapses. By the end of the season, it may look like a graying, irregular clump of dead grasses with plants emerging from the top. It's certainly natural, but not necessarily tidy. If tidiness matters to you or your neighbors, and especially if you live in an area where the appearance of your garden is subject to local regulations (such as homeowners association guidelines), you may want to consider siting your bale garden in location that's not in plain sight. Also keep in mind that with straw bales, your garden is nearly two feet off the ground; the added height may make the garden much more visible than an in-ground garden would be.
Excerpted from "Growing Vegetables in Straw Bales"
Copyright © 2015 Craig LeHoullier.
Excerpted by permission of Storey Publishing.
All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.
Excerpts are provided by Dial-A-Book Inc. solely for the personal use of visitors to this web site.
Table of Contents
Acknowledgments Introduction Chapter One: Getting Started Chapter Two: Gathering Your Materials Chapter Three: Planning for Success Chapter Four: Caring for Your Bale Garden Chapter Six: What to Grow and How to Grow It Chapter Seven: Problem Solving Chapter Eight: What Remains References Metric Conversion Charts Index