We’ve certainly all been affected by the smoke continuing to be a nuisance throughout our area because of wildfires both nearby (The Bobcat Fire is closest to me) and further away (throughout the state!).  Besides the inconvenience of keeping us indoors with the air conditioning running, our concerns run to the safety of our vegetable garden harvests.  Depending on how close you are to a fire, whether within range of burning structures and considerable ash, or merely smoky air and a few scattered ashes settled onto your soil, these two articles will provide you with the considerations you can make regarding eating your produce or not.
 
1.   Is it safe to eat my garden produce affected by wildfires?
https://extension.oregonstate.edu/ask-expert/featured/it-safe-eat-my-garden-produce-affected-wildfires
 
Q:  We have a lot of smoke in our area, is it safe to eat produce that has been affected by wildfires?
A:  First and foremost, stay safe when gardening in an area that is experiencing smoke and ash from wildfires. Avoid gardening and other outdoor activities when air quality ratings are in unsafe ranges. Wildfires produce a lot of particulate matter and large pieces of ash (gray gritty material) that can be moved long distances and be a health hazard. You can get an estimate of your area's air quality here: www.airnow.gov
     Once the air quality has reached safe levels to be outdoors, then you'll want to assess your garden. Until we get our fall rains you may see a lot of ash on garden surfaces including your plants. Many folks in our urban areas may see only a thin layer of ash, but if you live closer to the wildfire or where the wind was depositing ash there may be heavier amounts. Use your best judgment and avoid creating clouds of ash that you might accidentally breathe in.
     Don't use a leaf blower to clean plants or your garden; just a gentle spray of water from a hose will work and try to move the ash into ornamental landscaped areas like turf grass or shrubs rather than areas growing edible plants. Wear a face covering at a minimum while doing this, wash your hands afterwards, and avoid tracking ash into your house on your shoes or clothes.
     Rinse the produce off outside (with a hose or watering can) and then give a second or third rinse in the sink indoors.
     Now getting to your question about safety of garden produce after a wildfire: The produce was exposed to smoke and may have ash on it. The smoke and ash won't be able to necessarily penetrate deep into the fruit or vegetable and so rinsing well should remove any residues. Rinse the produce off outside (with a hose or watering can) and then give a second or third rinse in the sink indoors. Peeling (for example removing apple or tomato skins) and removing the outer leaves of leafy greens will also reduce your risk. And wear a face covering as need, wash your hands after handling the produce, and avoid tracking ash into your house on your shoes or clothes.
     Again, use your best judgment in all of this. If your garden has a heavy layer of ash, was located near a structure fire (which creates different toxins than a forest fire), or you are at all uncomfortable - when it doubt, throw it out (into the compost pile).
 
2.   The University of California has a research-based publication on produce safety and wildfires that you might find useful: https://ucanr.edu/sites/SoCo/files/315093.pdf . This publication also talks about soil testing and other things to think about before planting next year's garden. Note: this source recommends wearing an N95 mask but these are hard to find due to the current COVID-19 health situation needs. 

Stay safe out there!

For what to do in the garden once the air is clean enough to breathe heavily out there, go to September Monthly Tips.
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Fuyu persimmon putting out two differently-shaped fruits - pointed ones like Hachiya on left, and regular                                     flat Fuyu on right.

     Boy, what a way to blast into our cool-crop growing season - with threatened 115-degree heat for this weekend here in Pasadena.  Certainly brings back torrid memories of 116- degree heat a couple of years ago that fried a batch of my tomato plants, even with the deep watering I'd accomplished several days ahead of the blast.
     So, first off, go deep-water your garden NOW so the moisture can sink down to infuse the entire root system of whatever plants you still have producing in the garden before the heat actually hits.  For some of you, that's tomorrow.  For me in Pasadena, it's apparently Saturday, Sunday, and Monday.
     Second helpful measure to take before the heat is to cover plants lightly with cheesecloth or some sort of shade cloth, spunbonded polyester landscape fabric that will allow some light in but cut the blasting rays of the intensely hot sun.
     After the heat, the first thing to do is sprinkle the entire plants to help them rehydrate their leaves, spraying both topsides and undersides of all foliage.  I'd leave the cloth coverings on the plants for at least another week or so so they're not subjected to more intense sun now that they've been damaged.
      Also, deep-water to make sure root zones are fully hydrated.
     However, DON'T prune any dead-looking leaves and other damage that may appear next week.  You don't want to stress the plants even more by cutting off any browned foliage.  Despite any need you may have to neaten up affected plants, wait until you see new growth emerging - which may be more than a month - to see what actual damage occurred.  You'll be surprised how much more new foliage will appear in the areas that you thought were dead.  That's the time for you to trim off the dead stuff and even up any wayward growth.    
     More on this after the blast!

Transition Time in the Garden
     September and March are Southern California’s transition times in the garden, beginning their shifts from hot to cold crops (September) or cold to hot crops (March).  The hangers-on plants from the previous season are still producing but slowing down.  Seedlings for the coming season are just becoming available at stores, and seeds will begin germinating because of the changing air and soil temperatures. 
     But because we don’t know what kind of weather the next couple of months will bring, we can sow and transplant a last batch of warm-season crops like beans and cucumbers, okra, pepper and squash – as long as their maturity dates are no more than about 70-80 days, by which time it certainly (!) will be too cool for them to ripen properly.  And if the weather gets too cool before them, at least we tried a few in case the weather would have complied.
     If you want to concentrate now on starting cool-season crops, it’s time to get the soil beds cleared and amended so they can “cure” for a couple of weeks of microorganism activity before sowing and transplanting.  The mixture of manure and compost and other amendments like coffee grounds that have been incorporated and well watered will heat up as the microorganisms do their thing; when the soil feels comfortable again after a couple of weeks, you can sow seeds and transplant seedlings without risk of overheating them.
     So spend time now purchasing seeds of the crops you’ll be sowing.  
     The seeds of crops that will germinate at the top optimum soil temperature range of 85 degrees include asparagus, beet, bok choy, broccoli, Brussels sprouts, cabbage, carrots, cauliflower, Swiss chard, collards, kale, kohlrabi, leek, onion, parsley and radish.  So, sow these as soon as you can.
     Crops whose top range is a bit cooler – 75 to 80 – include amaranth, artichoke, arugula, fava bean, celery, endive, fennel, lettuce, mache, mustard, parsnip, pea, radicchio, rutabaga and spinach.  So wait another month or so to sow these.
     All of these have minimum temperatures down to 60 or 70 degrees, so keep repeat sowing them through the fall and winter and early spring for continuous harvests.
     If you have seed packets that are a couple of years old, the seeds may still be viable but with a lower germination rate, so sow them pretty thickly to see if you’ll get enough to germinate for your family’s use.
     Keep seedbeds moist and shaded from hot afternoon sun until the seedlings develop two to four true leaves.  Mulch the soil lightly to hold moisture for better germination
     Several companies offer individual varieties and collections of California wildflowers that are grouped by color or geographic area or other characteristics such as drought resistance.
     Bulbs to plant for spring bloom can be purchased now for first-choice quality. These include alliums, amaryllis, anemones, brodiaeas, crocuses, daffodils, freesias (so fragrant!), fritillarias, galanthus, baby glads, glory-of-the-snows, grape and Dutch and wood hyacinths, Dutch irises, ixias, leucojums, lycoris, montbretias, narcissus, paperwhites, peonies, ranunculus, scilla, snowdrops, sparaxis, tigridia, tritonia, triteleia, tulips, dog-tooth violets, watsonias, and winter aconites. 
     Choose big, plump bulbs, as these have the most stored food and will produce the largest and most numerous blooms over the longest period of time. They cost a bit more, but they'll provide a great deal more pleasure when they bloom. 
     Refrigerate hyacinths and tulips for six to eight weeks before planting them in November.  However, keep them away from apples and bananas, whose ethylene gas will destroy the flower bulbs ability to bloom.

More Garden Tasks
For more garden tasks, see September Monthly Tips.