Lasagna Gardening Pros and Cons

Plasting covering a garden
(Image credit: Joe_Potato / Getty Images)

Gardening sustainably in a way that improves soil and plant health is a responsibility of every land steward. There is some controversy regarding some methods, however, like lasagna gardening, that specifically relate to its benefits and efficiency. Lasagna gardening is a slightly lazy way of smothering out unwanted weeds and plants and enhancing soil over time. It relies on recyclable newspaper and cardboard as its main products in achieving this and has many benefits. The cons of lasagna gardening, on the other hand, include the consumption of time to build and finish beds, finding safe compostable products, the increase of certain pests and the site size in which it would work. Because of this, it's recommended that you consider both sides carefully and then make an informed decision best for you.

Lasagna Gardening Pros

Amy's viewpoint: I ascribe to the Type A and Type B personality theory wherein Type A people are more competitive, perfectionists, and impatient and Type B folks are the opposite. Type A people might call Type B people lazy. A perfect example of this includes those of us that enjoy implementing lasagna gardening methods. I'm a Type B person and see the numerous benefits of lasagna gardening. In contrast, others (Type A gardeners) may only see the downsides of lasagna gardening. In a valiant but no less vain attempt to sway the naysayers towards lasagna gardening pros, here are some of the best reasons to plant a lasagna garden.

It's cost effective. The first lasagna garden advantage is cost. This argument might possibly be the only one that will convince anyone known to pinch a penny or two. The whole point of lasagna gardening is to create a garden bed out of layered materials. Among these materials can be brown items (carbon) like newspapers, leaves or cardboard alternated with green layers (nitrogen) such as grass clippings, kitchen scraps, or coffee grounds. Because you are recycling everything you already have at home, the cost is significantly lower to complete a bed than if you bought plastic wrapped bags of soil that may have come from far away. Plus, you don't have to pay to have your cardboard and newspaper taken to the dump, or your compostable food waste either.

Improves soil. Additional benefits of lasagna gardening include the building up of soil. Lasagna gardens are perfect for areas with poor soil since they are built atop the soil surface. And the layers in the lasagna garden hold nutrients in the soil longer than if compost or fertilizer was applied to the surface of the soil. Since you are basically layering a compost pile, the process of decomposition naturally amends the soil so you don't have to, so nutrients last an entire season. As the lasagna garden is "cooking,"it breaks down into nutrient rich soil, rich in microorganisms. This improved soil holds water, slows evaporation and run-off, and keeps root systems cool.

Low maintenance. My favorite lasagna garden advantage has to be its simplicity. While it may be the lazy man's way, I prefer to enjoy my time in the garden rather than worrying with a lot of maintenance. With lasagna gardening, there is no need to dig or till and no need to dig out sod. All you have to do is alternate carbon and nitrogen materials and keep the "cooking" garden area wet. Lasagna gardening also blocks out weeds. Say no more to this lazy gardener! And it's certainly a better weed retarding option than a broad spectrum glyphosate herbicide that may be toxic to us and our pets.

Ready to plant when you want. Lastly, lasagna gardens can sit and "cook" for a few months until they are ready to plant, or for those that are impatient (Type A), you can put a layer of compost as the top most layer and plant the garden immediately.

Cons of Lasagna Gardening

Bonnie's viewpoint: Lasagna gardening makes sense in a way, until you take a closer look at the practice. Layers of compostable material intermingled with carbon sources, often discarded newspaper or cardboard, break down and improve soil nutrient availability, tilth and kill many pesky weeds during the process. Yet, there are downsides to lasagna gardening, even from the sustainable and organic contingent. Lasagna gardening is also called no-till, a practice touted for reducing carbon admissions, but this is one of the main reasons against lasagna gardening. Each part of the method has its detractors, giving us several reasons against lasagna gardening.

Carbon sources. Its fine and dandy to utilize recyclable paper and cardboard, but failing to send these to a recycling center means the paper mills will need to expend time, money and energy to create more of these high demand products. Instead of using these types of materials, turn to straw, wood chips, dry leaf litter and other dry, brown sources of carbon.

Slow nutrient return and soil oxygen content. As these heavy layers break down, soil oxygen levels are greatly reduced because they are more or less suffocated by the lasagna layers. Lack of oxygen means aerobic bacteria cannot do their work efficiently. This slows down the decomposition process and means that many released nutrients will not absorb into soil well but may, instead, leach away in rain run-off.

Time. One of the lasagna garden drawbacks is related to the amount of time it takes to gather and move all the organic material necessary for the carbon/nitrogen layering. The amount of time it takes for the layers to break down also comes into play as one of the major downsides to lasagna gardening.

Safety of materials. Many of our cardboard boxes come from overseas and from places where strict rules are not in place as to what can be in the dyes allowed on the boxes. These will leach from the cardboard as it breaks down. There may be petroleum products and certain chemicals that can contaminate your vegetable patch. It is difficult to verify the potential toxins in some carbon materials.

Garden size. It simply would not be practical to try to do an entire field in the lasagna garden method. Gathering enough paper and recycling would require a concerted, multi-faceted neighborhood effort. Unless you open a recycling drop off center on your land, you must source all the material needed for at least two layers of carbon. Take the square footage of your field and multiply it times at least two and you know how many square feet of newspaper you will need to find. This is one of the really impractical reasons against lasagna gardening.

Pests. While it is true that lasagna gardening will diminish some pests, it will encourage worms, slugs and snails. The worms, we can all agree, are a good thing, but not so much the other two slimy pests. Slugs and snails are major downsides of lasagna gardening but a bi-product of the practice. The layers create warm, moist spaces these critters love. Vigilance is then necessary to ferret out these plant munchers.

Lasagna Garden Drawbacks vs. its Benefits

Sure, there is some work and time involved, but there would be anyway to build and fill a raised bed. Yes, a lasagna garden takes a while to break down, but it's really just a few months, months in which Type B gardeners can be busy planning what to plant in the new beds! The pros and cons of cons of lasagna gardening must be carefully weighed. While the practice may be perfect for one type of gardener, it may be more trouble, expense and waste for another. The practice has good sustainable roots but the acquisition of safe material, time needed and other issues, may make it completely impractical for many. Overall, each benefit and detraction should be measured before undertaking a lasagna garden or any other composting effort.

Amy Grant

Amy Grant has been gardening for 30 years and writing for 15. A professional chef and caterer, Amy's area of expertise is culinary gardening.