“If you want to have the upper hand on weeds, you need to know every little detail about their existence.”

The above quote is straight from the great Jack Alex, retired botany professor and herbarium curator at the Ontario Agriculture College, who used to repeat it to me at every opportunity. Fortunately, most of us own a phone that will allow us to document and map pest activity throughout the season so that we can know the enemy. But first we must set our phone up correctly.

By default, you will have a date and time that your photo was taken (a great first step). However, let me walk you through what I do on my iPhone to capture weed emergence and growth patterns throughout the season, and to make sure that I know which fields the photos were taken in.

Step 1: Go to settings and tap the “privacy” icon and then tap on the “Location Services” icon (see figure 1 below).

Step 2: Make sure “Location Services” is set to “on” and then allow location access to photos taken by your camera by tapping on the “camera” icon and selecting “while using the app”. If you don’t want to geo-reference your photos (because it is sensitive information, perhaps an unflattering selfie), then be sure to select “never” before you take the picture (see figure 1 above).

Step 3: If you’ve taken photos with your phone’s camera and “location services” has been enabled, then when you go into the “photos” app, under “albums” there will be an album called “places” (see figure 2 below), where you can zoom in and look more specifically at where your pictures were taken (see figure 3 at bottom).

Why you would want to do this? I’ve found this incredibly helpful to get a better handle on weed germination patterns within fields so that I can time herbicide applications when the target weeds are more susceptible and get better results. For example, I know it’s impossible to control field violet in the spring because it flowers and matures very early, making it very tolerant to most herbicides. However, since I’ve been able to document that field violet emerges in early fall and is in the seedling stage during mid- to late-September (see figure 4 at top of page), these seedlings are much more susceptible to a number of herbicides and I’m easily able to control it and not waste money on management in the spring that is ultimately unsuccessful.

Have a question you want answered? Hashtag #PestPatrol on Twitter to @cowbrough or email Mike at [email protected].