Share This Page

Garden Q&A: Moss in veggies raises red flags

| Saturday, March 8, 2014, 9:00 p.m.
Jessica Walliser
Make sure your garden is getting enough sunlight and that the soil's pH is correct to get rid of moss.

Question: I am having a problem with moss in my vegetable garden. Is there anything I can use to eliminate it that is safe for the vegetables?

Answer: Your moss infestation is a symptom of a bigger problem. Getting rid of the moss will only remove the symptom; it will not fix the problem. Yes, there are soap-based moss killers that will kill the moss, but without making other adjustments, the moss will be back.

I suspect you have a pH issue going on with the soil in your vegetable garden. Moss prefers acidic soil conditions (its perfect pH is 5.5), while most vegetables thrive at an optimum soil pH level of 6.5 — still slightly acidic, but far closer to neutral than 5.5.

Test your soil's pH (soil tests can be purchased through the Penn State Extension Service) and follow the test result's recommendations by adding the suggested amount of lime to help raise the pH as close to optimum as possible. Here in Western Pennsylvania, our clay-based soils are naturally acidic, so most soil tests will indicate a need for lime every three to four years. Don't add lime, however, without getting a soil test first. Adding too much (or too little) can exacerbate the problem, leading to a whole different set of issues.

Another possible issue at play is the amount of sunlight your vegetable patch receives. Moss tends to grow in full to partial shade (though it certainly isn't unheard of in full sun locations), while veggies do best with a minimum of six to eight hours of full sun. If the limbs of any large trees overhang your garden, it may be a good idea to hire an arborist to trim the trees to allow more sunlight to reach the garden.

Drainage and soil compaction also may be issues. Moss is very shallow-rooted (they're actually called rhizoids, not roots), and unlike most vegetable plants, moss actually prefers compacted soil that is poorly drained and acidic, so keeping the soil loose and adding plenty of compost or another organic matter to improve drainage will help as well. If the area is low-lying and water tends to collect there, installing a French drain or drainage ditch may be necessary.

Horticulturist Jessica Walliser co-hosts “The Organic Gardeners” at 7 a.m. Sundays on KDKA Radio. She is the author of several gardening books, including “Attracting Beneficial Bugs to Your Garden: A Natural Approach to Pest Control” and “Good Bug, Bad Bug.” Her website is www.jessicawalliser.com.

Send your gardening or landscaping questions to tribliving@tribweb.com or The Good Earth, 503 Martindale St., 3rd Floor, D.L. Clark Building, Pittsburgh, PA 15212.

TribLIVE commenting policy

You are solely responsible for your comments and by using TribLive.com you agree to our Terms of Service.

We moderate comments. Our goal is to provide substantive commentary for a general readership. By screening submissions, we provide a space where readers can share intelligent and informed commentary that enhances the quality of our news and information.

While most comments will be posted if they are on-topic and not abusive, moderating decisions are subjective. We will make them as carefully and consistently as we can. Because of the volume of reader comments, we cannot review individual moderation decisions with readers.

We value thoughtful comments representing a range of views that make their point quickly and politely. We make an effort to protect discussions from repeated comments either by the same reader or different readers

We follow the same standards for taste as the daily newspaper. A few things we won't tolerate: personal attacks, obscenity, vulgarity, profanity (including expletives and letters followed by dashes), commercial promotion, impersonations, incoherence, proselytizing and SHOUTING. Don't include URLs to Web sites.

We do not edit comments. They are either approved or deleted. We reserve the right to edit a comment that is quoted or excerpted in an article. In this case, we may fix spelling and punctuation.

We welcome strong opinions and criticism of our work, but we don't want comments to become bogged down with discussions of our policies and we will moderate accordingly.

We appreciate it when readers and people quoted in articles or blog posts point out errors of fact or emphasis and will investigate all assertions. But these suggestions should be sent via e-mail. To avoid distracting other readers, we won't publish comments that suggest a correction. Instead, corrections will be made in a blog post or in an article.