You see them all over the internet but nowhere online do gardening fallacies proliferate more than on Pinterest.
For instance, we recently read a pin that described several ways to improve our garden soil, “naturally.” Among them was throwing a banana peel on the soil, or burying it, to supply potassium to your plants.
For the record, “As soil microorganisms work to break down the peels, they extract significant amounts of nitrogen from the soil, which results in less nitrogen for greening up plants,” according to Jeff Gillman of This Old House magazine. He suggests offering your plants a well-balanced fertilizer instead.
Read on for more common gardening myths.
Put small pebbles in the bottom of your planting pots
How many times have you read that container gardeners should add pebbles or place pot shards in the bottom of their pots to aid in drainage? Yet, this myth was busted more than 100 years ago, according to renowned horticulturist and professor, Dr. Linda Chalker Scott.
And, similar, more current studies prove that this is a myth, because “water does not move easily from layers of finer textured materials to layers of more-coarse textured,” the professor claims.
“Additionally,” she continues, “one study found that more moisture was retained in the soil underlain by gravel than that underlain by sand.
Therefore, the coarser the underlying material, the more difficult it is for water to move across the interface. Imagine what happens in a container lined with pot shards!”
So, stop with the pebbles on the bottom of your pots. Chalker-Scott suggest that you use only pots with drainage holes and high-quality topsoil to ensure adequate drainage.
Compost tea improves soil structure
Compost tea is a combination of compost and water that has been allowed to culture for a specified amount of time.
One online promoter of the use of compost tea has a list of its uses. Included on the list is that compost tea improves “nutrient retention in the soil,” reducing fertilizer use. The author also claims that the use of compost tea improves soil structure.
Compost tea does add nutrients to the soil. But, the only way it helps the soil RETAIN these nutrients is if it is applied frequently.
“The effects of compost tea are short-lived, and frequent and repeat applications are required” to replenish the soil’s nutrients and microbes, according to a 2015 study published in Advances in Bioresearch.
Horticulturists recommend ditching the water mixture and using dry compost as mulch. Each time you water, the nutrients will drip into the soil and provide those nutrients your plants are so hungry for. The bonus? Unlike tea, compost will improve the soil’s structure.
Always stake a tree when planting it
Chalker-Scott calls the process of staking a tree “tree bondage.” She does admit that there are some circumstances that call for using a stake to support a tree, such as when planting in “poor, shallow soils that hinder root development.”
But most of the time, staking a newly-planted tree is unnecessary and may end up harming the tree.
The stake takes on the support role of the trunk and root system. “This artificial support causes the tree to put its resources into growing taller but not growing wider,” Chalker-Scott explains.
Although a stake is supposed to be temporary, too often homeowners neglect to remove it. Those who do often end up with a tree that blows over or breaks during the first big wind. Chalker-Scott explains that this is due to the roots and trunk not fully developing because of the stake.
Bareroot trees are generally the only ones that require staking when planting. Chalker-Scott recommends that stakes be placed no higher than two-thirds the height of the tree. Use a flexible tie, such as a strip of nylon hosiery or other fabric that will stretch and not girdle the trunk.
Finally, remove the stake when the roots are established. Bartlett Tree Experts say that most trees’ roots are established within one to two years.