My garden scavenging life began when I was a teenager. Then, I picked up as many bags of grass trimmings from suburban neighborhoods as possible. Most people mulch-mow these days, so there are few bags of grass to be found. Back then in my area, no one seemed concerned about raking up autumn leaves, or if they did, they burned them rather than bag them to send to a landfill. Now people where I live deposit then in a dumpster which the city will empty for composting. If people bag up so many leaves they won't fit in the dumpster, and I find those leaves--yahoo!-- they are coming home with me. I also keep an eye out for straw bales fallen off on the side of the road. I will ask work crews who use them if I may have the remains, and I spy out neighbors who use them for autumn decoration. Many people do not want to deal with straw bales they've left on their front lawn once they've been saturated with several rains, begun to rot, and are perhaps frozen to the ground. In that case, have wagon, will travel. Straw in that state is excellent for the garden, even if I have to wait to spring to break it up.

I hear you on the rocks. When my child was young, before we homeschooled, I used to walk him home from school each afternoon. We walked across a small field where once there had been a clay pipe factory. You might guess I was looking for scraps of pipe, but I never found that. Instead I was scavenging chunks of limestone. Nearly all the old buildings here have limestone foundations set deep so that there is basement space under every building. That adds up to a lot of chalky white limestone. My son and I used to put small pieces in our back packs and carry one larger stone each in our hands. When we reached the ditch that railroad tracks run through, sometime we would toss our hand-carried rocks to the tracks so that we would not have to fumble with them as we edged down the hill. Reaching the other side of the tracks, we might pick up the rocks again and attempt to sling them up the other side of the ditch. Depending on the shape of the rock and the luck of the throw, they might not roll all the way back down to our feet. Once, I was doing some household chore when my seven year old came to me and asked, "Mom, why don't we build a bridge over the tracks?" Well, for eons that kind of initiative is the way things got done, so I was really pleased to hear the question, even if we did continue to carry those rocks in backpacks and in our hands, until we could find no more on the surface.

But then! Ah the old state psychiatric hospital nearby was closed and plans made to build little independent living group houses on the grounds. This meant the old limestone walls and wrought iron fences were torn down. More scavenging. It was surprisingly hard to find usable rock in those piles. Most of it was so weathered that it crumbled when the machines had knocked it over. We have lots of soft limestone in the soil here, so that is largely what has been used for such building. The harder, more decorative marble-like stone is saved for stairs, trim, railings, plinths, porches, thresholds, etc. I don't think I've ever found a piece of hard limestone.

Now, however, I do not have any of this limestone in my garden. I gave it all to my sister, who had beds that needed to be raised and edged, while I found that my own were better off not raised at all. With my sister, I once made a slow car trip between Memphis, Tennessee and St. Louis, Missouri, traveling the old hilly, curvy highways instead of interstate. We stopped at about twenty-bazillion road cuts in hopes of finding scavenge-able chunks of limestone, but again most of it was very weathered, not worth picking up. The lesson to me is that if I scavenge roadside for stone, I need to go to new road cuts, not the older ones.

When I lived in a neighborhood once described by an older German visitor as looking like Dresden just after WWII (an exaggeration), there was lots of that limestone available. Still, years later, my friend who gardens there finds all the foundation stones she can use and tells me I should just pick up any I may happen to need.

The city alleys are my biggest scavenging place now. Many people deliberately set out usable items in the alleys instead of putting them in the trash dumpsters. I have found a plethora of curtain rods that make light stakes for the garden, balls of twine, ready-made large sturdy tomato cages, small pepper cages, wood, hutches and shelves, an old oak table that was my potting table for years until it was retired to enrich the soil, bricks (oh, my bricks are so useful), terracotta tiles that I gave to yet another gardener to edge her mint and chives bed, eight foot steel pipes, bamboo already cut and dried, buckets and baskets (a gardener can never have too many), so many pots and cell packs/punnets, decorative aluminum corner support for back yard tents (these support vines now), a rake, kitty little jugs (for watering), full boxes of canning jars....

Hey, your neighbor's oak? One of my neighbors had a huge oak whose late afternoon shade reached my vegetable garden. I used to be so grateful for that. A few years ago, I recognized that it was infected with phytophthora https://en.wikipedia.org/wiki/Phytophthora , same disease as had killed my own small oak, my raspberries, and my other neighbor's rhododendrons. He tried trimming out the dying branches three years in a row, at great expense. This year the whole beautiful tree has been taken down. This will change condition for gardening in a large area. I think it was the largest tree within a half mile walk, unless there is something as large in the botanical garden or in the nearby "English walking Garden."