"Shadow lines can be visually measured for time of duration and a reducible estimate of their depth now, due to the steadily climbing arc of the early spring sun."

Go on, girl! Indeed! Lol.

When I'm making plans for new planting ideas, I get frustrated by the tree shadows in winter because there are no leaves on them so I feel like I can't make a good estimate of how much sun gets to a certain spot that's partly shady because it looks almost entirely sunny in winter! So tell me more about this reducible estimate!

Very roughly a reducible estimate for me! I'm not the math whiz of our family, that's for sure!

So, you know, if the shadow from fence "A" is three-quarters as long as bed "B" is now, once the sun gets as high as it will get, then how much lettuce can you expect to plant... and will it be enough to feed your entire rabbit population, or should you expand?

I was with you on A and B and then you added rabbits and my head exploded! Oh, no! No telling how many that could be! Lol, thank you for the tip--it will be helpful, and I shall insert an optimistic number of rabbits, deer, groundhogs... etc... (sigh)

All rabbit related joking aside, this is still one of the better times to try to figure out where deep shadows fall, and for how long they stay during the course of a day. For instance, I let a prominently positioned and easy to access area remain pretty bare for years before I realized that it was one of the better places we have here for gentle, sustained growth. I'd originally expected it to be too shady for many plants, but as I noted the long length of time when that area was actually bright, and then factored in the accompanying cooler spring temperatures, I realized that it was the perfect place for acclimating delicate plants until new growth appeared; lots of morning sun, no southern exposure, and plenty of late afternoon light with a bit of filtered sun...and I'd let it sit nearly empty for years! Now it's a very helpful nursery type area, and a great place for container plants.

Just last year I discovered a place like that accidentally during summer, realizing when marigolds grew and bloomed beneath an evergreen bough very happily despite the lack of noonday sun that I could use it for more than just leafy herbs. It became a pot ghetto by the end of summer.

Do you have a way of discerning shady areas beneath deciduous trees?

Just a fairly thorough, sunny day study during each season.

-In late winter even deciduous trees will throw enough of a shadow outline that you can reasonably judge where the heaviest shade will eventually be concentrated, or at the very least give you an idea of which areas to study further later on.

-Spring is harder to judge because there's less leaf cover, coupled with wind to add confusion. During breaks, I just move a lightweight chair or gardening stool around to unknown areas, sit, and check it out. During spring leaf-out it's sometimes easier to judge by how cool or warm exposed skin feels in different areas. If in one spot my skin is very cool, I think hosta or fern, if a spot five or ten feet away feels a bit warmer, I think heuchera, daffodil or delphinium.

-Summer, same way. The visual signs are much clearer because the trees are already fully leafed-out, but factor in what you learned in spring because spring ephemerals won't need sun during the summer.

-In autumn I take note of which trees shed leaves early (might be a good place for mums, monkshood or asters), which ones hold them till spring (darker almost year-round), and where the heaviest concentrations of leaves fall. I always leave most of the leaves in the beds they fall into, so once again I'd choose plants that want lots of organic matter for those planting areas. It just saves work all around.

(Did I get the drift of the question, or did I fly hopelessly off-base? I do that sometimes. )

That was way more than I'd hoped. I so appreciate your taking the time to give those examples and break everything down by season. Thank you so much, Chelle.

Great! I'm glad to help.