NEW! Garden & Outdoor Shop


Gardening Myths

Let's weed-out a few myths!

By Steve Piskor
Penn State Master Gardener
Certified Horticulturalist ©2016

Years ago, gardeners relied almost solely upon the knowledge of previous generations. Today, information about the optimal cultivation of plants comes from traditional print, websites and blogs, podcasts and television shows. Advertisements tout “superior” plants or products that will make your garden the envy of the neighborhood.

Regardless of the source, gardeners must ask if the information accurate. Can it be a myth that persists despite scientific knowledge to the contrary? Should it be buried in the gardening graveyard of questionable information? Myths may have no basis in science. They may be tied to products with no benefit to the consumer, and they may ultimately harm the plant. As spring is now upon us and gardeners trade snow shovels for garden spades, here are some gardening myths that have endured for decades...

Annual spreading of mulch creates a more perfect garden

Double shredded mulch

This ritual is one of the worst landscaping activities. Tree health can be greatly impacted by the use of excess mulch. Annual piling of mulch at the base of a tree creates a moist environment promoting rotting of the bark. Rotted bark provides an entrance for insects and disease. Excess mulch also provides a home for mice, moles, voles and other rodents, allowing them to gnaw the bark off the tree and gain access to the living tissue that intact bark was intended to protect. Tree roots will grow upwards into the mulch, creating roots that may encircle or “girdle” the bark at the base of the tree. Girdling roots lead to compression of the bark and the eventual strangulation of living tissue under the bark. Over a course of months or years this process will lead to the decline and possible death of the tree.


BOB'S NOTE: All trees become wider at the base, an area called the root flare. The root flare must always be visible, whether the tree is newly planted or long established. If the root flare is not visible, the tree base has been over-mulched, or the tree has been planted too deeply. Be sure to check that containerized trees have a visible root flare.

girdling root diagram

Watering a plant on a sunny day can cause leaf burn

It was thought that sun shining through a drop of water on a leaf would act as a magnifying glass, causing a burn spot on the leaf. But for the water drop to act this way, it has to be at a ‘specific focal point distance’ to concentrate the sun’s rays. Sun shining through a drop of water on a leaf does not meet this criteria, and such a theory for leaf burn is a garden myth.

Drought-tolerant plants do not need to be watered

All plants must be watered until they are established, over the course of one or more growing seasons. Once established, some plants can handle extended dry periods better than others. The key word is “tolerant.” Plants may tolerate various moisture conditions, but they will not perform their best. The bottom line is that a drought-tolerant plant needs to be watered regularly to thrive in, rather than tolerate, its growing environment.

hens and chicks
Even drought-tolerant plants like sedum
need to be watered regularly to thrive

Hummingbirds feeders must be red

Some scientists believe that hummingbirds are attracted to red and purple flowers because blossoms of these colors have the ‘sweetest’ nectar. Experiments using feeders in a range of colors have indicated that the feeder color is not important. Provide fresh nectar using a solution with a 4:1 ratio of water to sugar and the hummingbirds will flock to your feeder. Be sure to keep the feeder clean and add fresh solution every four days.

Vitamin B1 helps to prevent transplant shock and stimulate new root growth

There are products on the market being sold as “root stimulators.” Products containing rooting hormone and/or fertilizer can help get plants off to a good start. The addition of the vitamin B1 sounds extra healthy, but it is of no value to a plant.

Penn State Nittany Lion

Get the facts. The Penn State Master Gardener volunteer program supports the outreach mission of Penn State Extension by using unbiased, research-based information to educate the public and our communities on best practices in sustainable horticulture and environmental stewardship.


Straw Bale Gardening

Gardening with Purpose

Gold-colored perennials for shade


home | terms of use | contact | search | site map
lawn & garden store
Copyright ©2017  DONNAN.COM  All rights reserved.