Good harvet, bad harvest

This person got 260 pounds of cherries off their tree this year. Yet in the comments on the photo (posted on Facebook) one person lamented that they got basically no cherries off their tree at all! Why is it that some harvests go well and others not so well? Here are the main reasons, and some solutions.

1. Climate change. Notice I did not use the phrase "global warming" because the phrase "climate change--while it includes heat waves and drought--also covers severe storms and bad winters. In my region (the American Southeast) we worry about hailstorms, occasional drought, heat waves, and and too mild or too cold winters. It was TOO mild last winter and the peach trees below a certain latitude did not really bear fruit. The winter before that we had the worst snow and cold in decades: any southerrn trees on the edge of cold tolerance might have died. The solution to this is to plant redundant things that are slightly different. We now have two varieties of peaches--a Redhaven and a native whiteflesh peach. One may fruit when the other does not. We also have different choices than peaches: two varieties of apple, two varieties of grapes, cold hardy orange, fig, mulberries and raspberries. Three kinds of taters. Three kinds of lettuce. Diversification is the key.
2. Insects and other pests. We used 1/4-inch hardware cloth under our raised beds to keep out a plague of moles, but I've seen urban rooftop gardeners use kiddle pools as containers and suppose that would have worked as well. Bird netting is an eco-friendly way of protecting fruit that really works, but so is providing a "distraction tree" full of berries the birds prefer to your crop (we use mulberries). Tin pie pans spinning in the breeze will keep off squirrels and birds for two weeks of a harvest, until the animals get habituated. Floating row covers work better than I would have thought to keep insects off of most things, and BT (bacillus thuringiensis) is a godsend, although those morons at Monsanto have  bred something that may make it less useful over the long term. Picking tomato hornworms off your kitchen garden crop by hand and then stomping them is very satisfying. Diatomaceous earth will kill a lot of insects - you can get it at pool supply stores. I'm still open to suggestions on how to deal with those bastard Squash bugs, though.
3. Watering issues. One of the biggest learning-curve items for me was discovering how LITTLE water my garden needed, once seed was started. Judicious watering of certain things such as figs has increased my yeilds but certain crops could be harmed by too much water. Tomatoes will split if over-watered, and oranges will drop all developing fruit. So I make sure my lettuces, beets, cukes and green beans get water once every three days and am careful to avoid watering my tomatoes unless they droop a little. And now that it's established the orange tree is on its own, water-wise.
4. Soil issues. I was also too gung-ho in adding organic material to my garden, to the point where the raised bed soils became a paste that kept out water and air - and plant roots need both. The local agricultureal extention service analyzed my soil for very little money and when I added sand, crop yeilds soared. Blueberrries need acidic soil, so newbie me ruined the natually acidic soil here and put wood ash on them. The fig tree loved the wood ash; the blueberry bushes died. Find out what the soil requiements for your particular crops are. You may need to supplement things with epsom salts, for example.
5. Timing issues. We all know that fall panting is a good time to put in trees and bushes, and I have two blueberry bushes that I will be moving now that things have cooled a bit. But planting times for annuals are much, much trickier. One reason crops fail is that they are planted too early or too late. Early peas will not grow if planted too late; autumn crops will wither if planted too early in teh depths of summer. And when things should be planted my not be intuitive! In my climate, parsnips have to be planted in November, a fact which surprised me. Again, my local agricultural extension clued me in.

If you believe, as I do, that food will soon become much more expensive (and even scarce) a good or bad harvest could become a litteral matter of life and death. But that's only a worst-case scenario. I'm not saying we should all become subsistence farmers but our budgets will gain a lot of breathing room if we can all grow rather than buy as much as possible. And let's not forget how much healthier home-grown food can be. Finally, I get a lot of satisfaction that my chicken was grown in a nearby town, my bread was made from local winter white whole wheat, and my salad was from my kitchen garden: no 3,000-mile chicken salad for me!