Bill McGinnies' flowering calendar

The Bill McGinnies Desert Flowering Calendar

Bill McGinnies' flowering calendar
Bill McGinnies' flowering calendar for Sonoran Desert annuals, compiled from his field notes of many years. (click to enlarge)

It’s February and you know what that means. Time to get out your flowering calendar. Bill McGinnies, one of the last of the original Desert Laboratory scientists, created the only one I know of? and I found mine recently while sorting through 30-year-old old files in my studio. He had even signed it to me.

I remember designing this and putting together the mechanical artwork when I worked for the Office of Arid Lands Studies. It was almost 30 years ago. I had to send out the type to be set on a phototypesetter, then sliced it, waxed it, and pressed it down onto my layout board. I even remember that Kevin Dahl did the typesetting. The illustrations were by botanical illustrator Lucretia Breazeale Hamilton. I had to photostat those and paste them up too. I was proud of it at the time, though it would be so easy to do on computer now.

I’m going to re-publish it here because I have one, maybe the only one left. Also as a memorial to Bill McGinnies who paid such scrupulous attention to all these ephemeral plants for 17? years to gather his notebook full of data. The file here is is printable on 11×17 paper if you want to do download it and do that. It makes a good checklist for the flowers you have seen.

The Sonoran Desert is a complex place and life can be complicated, especially for annuals. Those are the desert flowers that we hope for every spring. Sometimes there are a lot, sometimes almost none. Every decade of so there is a banner year where the desert is carpeted with flowers. These desert annuals can’t handle heat and dryness at all, but their seeds can. These seeds might lie in the gravel for years before they sense the right conditions where it is safe to bloom.

What are these conditions? Bill McGinnies knew. And I have to look at his calendar every few years so I can remember, it’s that complex. On a walk yesterday, I saw a number of these blooming already.


It did rain a tiny bit this afternoon. I don’t know if it was significant for the annuals or not. It was almost not measurable. I recorded 0.05 inches on the Tumamoc Rain gauge chart. Although I do not worship any rain gods, I am a desert dweller and it feels like I’m taking part in a sacrament of some kind when I check the gauge. This old gauge has been checked and recorded continuously since 1909, so I feel like I’m part of a lineage. It’s a ritual specific to this place too–the rain will vary from a gauge a half mile away. So that’s what fell in this small place

annual seedlings sprouting on Tumamoc Hill
Annual seedlings sprouting last Januray, taking a chance with life on Tumamoc Hill. They'll need one more rain to make this a banner year for wild flowers.

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