Plant Symptom Chart

Method

How we check each line

Every statement on this site comes from a named university Extension page. Here is how we pick those pages and turn them into a chart.

Which sources we use

We only use Extension services whose terms allow their facts to be summarized and linked. Community forums, question sites and garden shops are not used as sources, even when they rank well in search.

How a line gets onto the chart

  1. We read the Extension page and note what it says a problem looks like: the color and shape of spots, which leaves go first, the weather it follows, what it is easily mixed up with.
  2. We write that in our own shorter words, starting with the name of the service that said it. We do not add details the page does not give.
  3. For every line we keep the exact passage it rests on. Before the site is built, a script checks that passage is still word for word on the saved copy of the page, and another script stops the build if any sentence on our site copies the original wording at length.
  4. Each line shows the date we last checked the source page.

What we leave out on purpose

We do not name any pesticide or give rates or home recipes, and the build is set to fail if one slips in. Product labels and local rules differ, and the Extension page linked in each row is the right place for that advice.

We also do not say whether a plant or a problem is harmful to people or animals. Ask your local Extension office or a plant diagnostic lab if you need a firm answer.

Empty cells

If one service describes a cause and another does not, the other cell shows only a thin grey line, and a service with nothing to say about a whole symptom is left out of that table. That only means the pages we compared do not mention it; it is not a disagreement.

Pages we compare

Colorado State University Extension

Clemson Cooperative Extension

University of Wisconsin–Madison Extension

Corrections

If a line no longer matches its source, or the source page has moved, write to us from the about page and we will recheck it.