Guest Contributor: Cassey Anderson, Horticulture Agent, Colorado State University Extension
What does organic gardening mean? There are several different ways you can consider the term organic in relation to the vegetable garden. This article is intended to inform you of some of the differences, but it is up to you how you want to manage your own landscape.
These are some of the definitions of organic as they relate to the garden:
• Organic – chemical definition meaning it is or was once alive
• Organic practice – growing in such a way that you minimize use of pesticides and use organic fertilizer
• National Organic Standard / certified organic – this is a label for commercial production
Let’s dive into what each of these definitions mean and how they can impact you as a vegetable gardener.
Organic chemical definition
From a chemistry standpoint everything is a chemical and whether it is organic or not is defined by whether it contains carbon, or if it is or once was alive. So, while rocks, water, metals etc. are inorganic, worms, wood, plants, and people are all organic from a chemical perspective. This definition is separate from the definitions we’ll get into next, but when you hear someone recommend amending soil with organic matter, or mulching a landscape with organic mulch, it is likely that they’re referring to using material that was once living.
National Certified USDA Organic
USDA Organic is a certification label that tells consumers the way the food was produced. The goal of organic is to follow best practices to encourage biodiversity and preserving local ecology. This means that organic growers cannot use synthetic fertilizers or pesticides. Some synthetic products such as alcohol, acids, and soaps are exceptions for use. Plastics are also allowed under organic practice and are a common approach for many growers to reduce weeds in vegetable beds. Pesticides are allowed in organic production but must be certified by the OMRI certification process. Growers must be certified organic to sell with the label if they produce more than $5000 worth of organic products each year. If you want to know more about the National Organic standard and how to become certified organic you can learn more at the USDA National Organic Program. If you want to know more about input products such as fertilizers and pesticides in organic production and how they are certified, you can check out OMRI certification.
Organic Practice
This is the umbrella under which many homeowners may fall. Within organic practice it is not allowed to label your produce as “certified organic” but you can state that you follow organic practices.
Within organic practice many gardeners focus on:
Soil health
Healthy soil can withstand more stressors and can sustain plant production more easily than depleted soil (although hydroponic production demonstrates that with the right balance of nutrients soil is not, strictly speaking, necessary). The best start to determine what type of soil you have is to perform a soil test on your space. You can sample 4-6 areas around your vegetable garden, take the sample about 6” deep. Remove any debris, large material, or rocks and dry the sample thoroughly. Most soil testing labs need about two cups of soil to analyze. Knowing where your soil nutrient profile is can help with what you may (or may not!) need to amend to best support plant production.
Ensure you have good drainage, or raise your beds if your soil drains poorly. Vegetable gardens need about 4-5% organic material (this being the chemical definition of organic) in the soil to sufficiently grow most vegetable crops without supplemental fertilizer. If your soil tends toward being sandy, the organic material can help it to hold more water and nutrients. If your soil tends toward being clay, organic material can help improve drainage.
Biological diversity
When reducing the use of pesticides in the garden you may want to focus on increasing biological diversity. In more traditional gardens it is common to find vegetables separated from ornamentals and crops planted closely together. To encourage biological diversity in your garden (which has many benefits) you may decide to plant flowers and vegetables with each other. This can do several things, it can break up the “buffet” for insect pests or diseases, it can attract beneficial insects and predators, and finally it can be aesthetically pleasing. There is not a lot of substantiated research behind specific companion plants but by growing a wider diversity of plants you can increase the tolerance of your species.
Another approach for biological diversity is to plant a wider variety of vegetables. Perhaps you love spinach, maybe grow Malabar or New Zealand spinach in addition to traditional spinach. Plant legumes and leave their roots in the ground to help provide additional organic material and nitrogen for future vegetable plantings. By changing up what vegetables (and ornamentals) you plant, and by rotating plant families, you can simultaneously improve your soil and your biodiversity year-over-year.
Effective and efficient watering and fertilization
By doing a soil test as explained above you may be able to get a sense of what your soil is going to need in terms of water and fertilizer. If you get plenty of natural precipitation you may not need to worry about watering too much, but if you do not, coming up with a way to irrigate that reduces water use can be beneficial (hint: drip irrigation, it’s the most efficient and may reduce the spread of disease). Your soil test will also let you know what nutrients your soil has, or which it needs. You can source organic fertilizers to supplement where you are lacking, but also work to amend your soil with organic material to provide more nutrients.
Caveat: when considering amending your soil with organic material such as compost be sure to do so gradually over time. Adding too much compost at once can offset the balance in your soil and cause nutrient deficiencies.
Attracting pollinators and beneficial insects
This goes together with increasing your biodiversity but is worth a standalone point for several reasons. Firstly, attracting pollinators to your garden is likely to improve your vegetable production. Second, having a wide variety of pollinators and other beneficial insects can help to create a more sustainable landscape in the long term. How do you do this? Plant a wider variety of flowering plants and leave your plants in the winter. This will allow insects to overwinter successfully. Many insects will burrow into hollow stems or at the base of plants to overwinter, so if we cut them all down in the fall it will eliminate their habitat. There are numerous guides and suggestions for attracting more pollinators to your landscape.
Organic vs Conventional Fertilizer
One place where things can get confusing in the discussion of organic vs. conventual gardening is fertilizer. The first thing to know is that the plants themselves don’t have strong preferences for how they get their nutrients, they just want to get them. The means of getting them can have an impact on your overall landscape health however as many organic fertilizers can have a secondary benefit of improving your soil when used.
It’s easy to harp on synthetic fertilizers, but without them modern society may not have been possible. Nitrogen is produced through the Haber-Bosch process which takes atmospheric nitrogen, combines it with hydrogen under high pressure and converts it into a plant-available form (there are many forms which is a little outside of the scope of this article but you can read a good summary here). Synthetic fertilizers tend to be rapidly available to plants and can run-off or burn if applied in excess.
Organic fertilizers are types of nitrogen that are already made available to plants because they come from previously living materials. Some examples include bone meal, blood meal, fish emulsion, worm castings etc. Organic fertilizers take longer to become available to plants and are often lower in percentage of nutrient.
One note about nutrients vs fertilizers. While nutrients can come from fertilizer they can also come from compost, plant debris, compost tea, or other less quantifiable sources. Fertilizers are required by law to guarantee the quantities of nutrients listed on the label. When reading a fertilizer label, the numbers on the front, typically written 10 – 15 – 10 are Nitrogen, Phosphorous, and Potassium. These numbers will be a guaranteed quantity (percentage by weight) in both synthetic and organic fertilizers.
What about weeds and pests? In an ideal world an organic garden would give us enormous yields and we would never have to battle with weeds or with pests. Unfortunately, this is not the case. Cultural practices such as those explored above like effective watering and fertilization, increasing biodiversity and encouraging beneficials should reduce weeds and/or pests but likely won’t completely eradicate them. There are organic pesticides that you can use if necessary. Do note, that the definition of a pesticide is something used to kill an undesirable pest. This means that even though a pesticide may be organic it does not always guarantee that it is safe. Be sure to read and follow all label instructions when using any pesticide whether it is organic or synthetic.
See our article on "Organic Pest Control" here.
Hopefully from this discussion you can see that organic gardening has some excellent principles behind it, but it is not always a simple black and white practice and there are many levels to which you can adhere (or avoid) depending on what works best in your life and gardening style. As always, reach out to your local Extension office if you have additional questions.
As always, reach out to your local Extension office for further information if you have any questions.
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