Root Out Research Before Taking Garden Advice

By Marsha Goldberg, Fairfax County Master Gardener
I am often strangely intrigued by information I uncover on the Internet or read in magazines that promises fewer weeds, larger flowers or a huge crop of vegetables simply by using items from my pantry, fridge or medicine cabinet. You know…whirl up a concoction of garlic and chili powder to keep away rabbits, put out pans of beer to trap slugs, or cover newly planted seeds with toilet paper to keep birds from eating them. And, come on, admit it, haven’t you done something like that — sprayed your tomatoes with Epsom salts, maybe? I have!

My professional background (in another field) and gardening experience have taught me that it is usually worth the time to determine whether legitimate research or evidence exists to support claims such as these. It is tempting to try new ideas, but horticulture is a science, and it is wise to research the evidence behind the claims of new products or methods before putting your plants at risk.

If you want to learn more about a piece of gardening advice, one of your first steps might be to search the Internet, which, unfortunately, will often lead you to sites providing information based on myth or folklore rather than research or evidence. It is often difficult to distinguish legitimate claims from those that are not supported by research; after all, who would think that planting tomatoes sideways is a good practice? Washing insects off your houseplants with dish detergent, a traditional tactic, sounds sensible; it turns out that it is not such a good idea these days because of a change in soap formulas.

If you are looking for information, cooperative extensions can help. The cooperative extension in each state is funded through a land-grant university, with the purpose of disseminating research-based information to farmers, gardeners, landscape professionals and other residents. You can be sure, then, that information you get from a cooperative extension site has evidence to back it up. And, to make your search easy, you can use the Cooperative Extension Search site,, which will give you information from cooperative extensions throughout the country.

To conduct a wider search — that will include information from other universities in addition to the land-grant institution, all of which will have the extension .edu in their URL — use the search term For example, if you want information about aphids, you would type aphids Your results will include only university sites.

Increasingly, horticultural professionals and garden writers are taking issue with touting unproven garden remedies on the Internet. The resources below can provide you with more information about this topic. Master gardeners rely on and disseminate only information that is based on research and evidence. By using the same reliable resources as we do, you can have confidence that you are using best practices to create a healthy and sustainable garden.

References and Resources
Garden Professors
Horticultural Myths, Linda Chalker-Scott
The Truth About Garden Remedies: What Works, What Doesn’t, and Why by Jeff Gillman
Decoding Gardening Advice: The Science Behind the 100 Most Common Recommendations, by Jeff Gillman and Meleah Maynard