How to Have Fun with the New Hardiness Map

Since I just got done telling you what the new USDA Hardiness Map is not good for, I thought I should at least show you how to have some fun with it. Okay, not rolling on the floor laughing fun. Probably more like, “what can I do instead of my taxes?” fun. But, hey, fun is defined by the alternative. The USDA says its new map “enables viewers to examine plant hardiness zones at a much finer scale than ever before.” We’re going to see just how fine we can get it.

Find Your Coordinates

In your own mind, choose a place whose hardiness you want to know. No, you don’t have to tell anybody, but let’s just assume it is your own garden. First, you need to know the latitude and longitude of that place. If you don’t happen to have it memorized, go to Google Maps and type in the street address. Right-click on the location marker and choose Drop LatLng Marker from the little menu that pops up. Write down the coordinates (low tech), or do the next step in a new browser window (low stress), or go ahead, memorize the coordinates (nerd!). Suit yourself. If you have some easier, better way to get the coordinates, you can tell me in the comments.

Enter Your Zip Code

Next, visit the new hardiness map site. Make sure you’re on the interactive map tab. Unfortunately, there’s no way to directly enter the map coordinates we obtained in step one. We have to achieve our goal through a rather kludgy process. Enter the zip code for your chosen location in the box provided, right under the words Interactive Map in the upper left corner. (If you don’t know your zip code, look it up here.) Click the Locate button, if you haven’t already figured that out.

Zoom In With the Best Base Map

Now you are in the general area. But you can get much closer. You can move the map around by clicking on it and holding down the mouse button as you move it around. Slide the zoom level all the way to the top so you are zoomed in as close as possible.

Now, slide the Zone Color Transparency all the way to 100. This has the effect of removing the zone colors, revealing the map underneath. Please note you can change the base map to terrain, road map, or satellite image. Use whichever helps you pinpoint your location best. I couldn’t zoom in close enough on my location to see my rural road, so terrain actually worked better for me.

Click Marks the Spot

The moment of truth has arrived. Click on the spot that you believe is your chosen location. A little box will pop up, informing you of the zone, the average temperature of that spot, the temperature range, and the latitude and longitude of the place that you clicked on. This is how you determine how accurately you clicked on the exact, precise location you desired. In my case, I was .01078 off in latitude and .00470 off in longitude, so I feel like I got it close enough. At my new house, I am Zone 5b, the average winter low is -13F (-25C), and the range is -15F to -10F (-26.1C to -23.3C). At my old house, I could see the road on the interactive zone map when I was all the way zoomed in, and I was only off by .00096 in latitude and .00068 in longitude. Pretty much right on the mark. Here at the old place, it is also Zone 5b, the average temp. is -13.9F, and the range is exactly the same. Keep in mind these are interpolated results. I have found that if you click around in the same general location, you get a different average temp every time. Whether it really means anything is another story. But, hey, it beats doing taxes, right?