Leaf Musings

Posted by: Mary Small - State Master Gardener Coordinator

Leaves accumulating in front walk next to garage (r)

“I think that I shall never see a poem as lovely as a tree…” I reminded myself during a fall leaf cleanup. And yes, trees are wonderful, but I could do with a few less leaves in the front walk every year. The picture on the right greets me every couple of weeks during the fall months. Every fall.  It’s worse when the weather is windy. And lest you think the front steps are not affected -I swept them off before I thought to take the picture.

Instead of continuing to wonder why the neighborhood leaves end up in my front walk, I did a bit of research. Now, I’m not an engineer, but here’s what I understand. The wind hits the windward end of the garage and flows up over the roof and around the front (side) of the garage. Suction is created on the side wall of the garage and on the leeward side of the garage– which is where the front walk is located!
So that explains (at least in part) why leaves get “sucked into” the front walk. And it also explains why leaves get sucked into the garage when it's windy and the doors are open – like when you’re putting the car in it!




While cleaning up this batch of leaves, I wondered what species were filling up the walkway, since we only have one tree in the front yard. Digging through the pile I found about 10 different kinds of leaves.  Our tree could have been the source of the bur oak leaves (brown, far right). The nearest ornamental pear trees (bottom center) are 4 houses to the north and should have had plenty of opportunity to bother someone else before they arrived on my doorstep. There are numerous aspen (lower right, brown) across the street in at least 3 yards. The nearest cottonwood (upper left, brown) is at least three blocks away. I have no idea where the maple or red oak are located.

I next re-sorted the leaves. Look at the gorgeous anthocyanin pigments in the three beauties on the left and right.The pigments are present all year, but we only get to see them when chlorophyll – the green pigment- is no longer produced in the leaves. This happens in response to decreasing daylength and other factors as we approach fall.

Finally, I just had to put this mighty cottonwood leaf next to its more diminutive aspen relative.

I ended this work session thinking that tree leaves are really cool. (Remind me I said that in a couple weeks…)