You can bring the summer to a triumphant close instead of letting it peter out. These tasks will really make a difference with area 2 on your list--plants that are basically well-grown and ready to produce for you, but getting tired, hungry, stressed, or drained by pests. These are the tasks that bring big rewards.
Zucchini can get pretty tired and hungry after pumping out squash all summer. Any plant that produces over a long season, like pole beans, okra, peppers, chard, or cucumbers can use a snack about now. Solution: Give your hard-working plants a layer of compost, a dose of fish emulsion, a dusting of alfalfa meal, or some other nitrogen source. To make your own probiotic fertilizers, see our directions HERE. (Tomatoes shouldn't get too much nitrogen--compost is perfect. To cure blossom end rot, give them some fast-acting calcium--CalMag or wood ash.)
Problem: Weed Competition
Weeds can take over in a hurry, especially when really hot days make hoeing or weeding a misery. Solution: If possible, set aside a time in the morning or evening to do 15 minutes of weeding. The key is to keep it simple, manageable, and repeatable. (I like to take a glass of wine out with me and watch the day fade and the birds go home to roost.) As you deal with the weeds, make a plan for prevention. Weeds need light and moisture. If you can deprive them of one or the other, with mulch, cardboard, plastic tarp, or shutting off the water, you will have less of a problem.
As you finish each area, even if it is only 1 sq ft, mulch it. I have big swathes of weeds where I was waiting to mulch when I finished the whole bed. Don't follow my bad example!
If there are patches that are too overrun to be worth saving, fine. That's a perfect place for fall vegetables. Get out the hoe and erase the problem. Remember that Fall is the Season of Forgiveness in the Garden; you get a fresh start.
Problem: Tiny Bloodsuckers
Thrips, mites, whiteflies, and their ilk are the bane of the late summer garden. Often too small or hidden to see, you don't know they're there until there are lots, which is now.
They attack the lowest leaves first. They suck sap out of the leaves. The leaves develop a silvery or white speckled or stippled appearance on top, where the juicy middle of the leaf has been sucked away from the outer skin. Sometimes the leaves curl. With spider mites you sometimes see webbing, like spiderweb. You can often see dark specks of excrement and discolored patches that have been sucked dry. What you often won't see are the bugs themselves. They are tiny. You might want to invest in a little pocket microscope. Thrips are large enough to see with a hand lens or even your naked eye sometimes. But mites are pretty much invisible. Aphids, scale, and whiteflies are all visible, but small. Unless you turn the bottom leaves over, you may not see them.
Solutions: These should be multi-pronged and repeated over time. They include keeping weeds down; having lots of small flowers in bloom, especially alyssum, which hosts a major mite predator; mulch; removing lower leaves and branches that act as a ladder for the pests; and spraying with solutions that knock down soft-bodied pests while not damaging their predators. (The photo above shows a minute pirate bug eating pests.) I would start by spraying compost tea. It is the least disruptive to beneficials, and it strengthens the plant so it can fight back. Soap-based sprays can work, especially when they include essential oils like peppermint and oregano. Enzyme-based sprays work well. They are non-toxic and work by digesting the outer skeleton of the pests. (Using an enzyme found in the guts of earthworms, which dissolves the skeletons of the soil organisms they eat.) The brand I am familiar with is called Dr Zymes. I also use it for mildew, which is another late-summer plague. The key for mildew is often to change the pH of the leaf surface, and to add probiotics that prevent the mildew organism from spreading. Compost tea is a good place to start.
Jamie Chevalier lives and gardens on a river in the Coast Range. She has gardened professionally in Alaska and California, as well as living in a remote cabin and commercial fishing. She wrote the Bountiful Gardens catalog from 2009 to 2017, and now is proprietor of Quail Seeds.