This calendar’s monthly planting guidelines are based on USDA zone 9, but they are adaptable to most zones. To find your zone, go to the National Gardening Association’s website. If your zone is 7, 8, or 9, you can safely use this guide. If your zone is 4, 5, or 6, then add a month before beginning your spring tasks and start your fall tasks a month earlier. If your zone is 10 or 11, subtract a month to your spring tasks. Your fall and winter tasks should remain the same as the original guide if you are in zones 10 or 11. These are all general guidelines. Your specific microclimate, which depends on distance to a large body of water (like gigantic lakes or oceans) and elevation, will make your zone fluctuate. Consult your local county extension office, found here, to get more detailed zone and planting guide information.
Tasks for August:
- Stop pruning
- Seed save
- Watch for late blight
- Share your bounty
- Continued maintenance (spray, bugs, fertilizing)
August is the time that you can start pinching suckers. You’ll want to let them grow in the first few months because suckers do have the capacity to flower and fruit. However, starting in August, it’s too late in the season for any new suckers to have enough time left to ripen any fruit they could develop. So it’s best to force the plant to put its remaining energy into ripening the fruit already forming on it. The exception to this rule are cherry tomatoes—these could still give you ripe fruit going into November, depending on your microclimate.
The exception to the “stop pruning” rule is if you haven’t done enough pruning (or removing) of crowded interior leaves. Start doing this or continue in earnest. Remove crowded leaves in the interior of your plants that are blocking sunlight and airflow. This helps with pollination and disease control, and it helps ripen fruit.
Saving seeds is a fun and cost-saving thing to do right about now. You’ll want to save seeds from your best-looking fruit, from your best-looking plants, and only from heirloom (aka open-pollinated) varieties. You don’t want to spread the same diseases from generation to generation. Not all diseases can be spread genetically, but there are enough of them to be cautious about which plants and which fruit you choose. So save seeds from only the healthiest plants and only exemplar fruits. For example, an “exemplar” fruit means a true representative of its nature. So you wouldn’t want to save seeds from a smaller-than-average Green Giant. Nor would you want to proliferate a Ruffled Yellow by using a smoother fruit as the mother seed.
Best practice is to save properly representative fruit from more than one plant of the same variety. If you are growing two or more Black Cherry plants, then take sample fruits from all of them (as long as they are all healthy). This will diversify the population and help keep your seed stock from becoming inbred. If you have neighbors or friends growing the same variety, try to get a couple of fruit from them as well to mix with your own.
Don’t try to save seeds from hybrid tomatoes—you won’t get the same type of tomato you’re looking for if you do that. Hybrid tomatoes only “sow true” in their first generation. And that’s the generation of plant you grew in your garden this year. Save seeds from heirloom—otherwise known as “open-pollinated”—varieties because typically they will “sow true.” That term means you’ll get the same type of tomato. The small exception to this rule is if your tomato happened to have been cross-pollinated, but that is not likely to have happened. Tomatoes usually self-pollinate; their flowers have both male and female parts to them, and pollination usually occurs inside the same flower. So bees are not necessary for pollination, only the shaking of the flower at the right time to get the pollen (from the male stamens) to fall on the pistil (female ovary). This “shaking” usually occurs with wind movement, but bees or fans also work. The tomato flower is not using the bee’s pollen delivery; the blossom is using the bee’s vibration as a helper. The fruit must be ripe, otherwise the seeds will not be viable or a lot less of them will be viable.
Saving seeds for tomatoes is easy: Cut the fruit in half through its equator (rather than through its stem end). Squeeze the seeds and their surrounding juice and gel sack into a cup or jar. Add about an inch of water to the slurry. Label the receptacle. If you use disposable plastic cups, you can write on them with a permanent marker. Note the variety name and the date, and write the word “Save” on the exterior. If you don’t, someone may come along and dispose of your carefully saved seeds.
Place the labeled receptacle in a somewhat warm location. Ambient household temperature is fine; however, don’t expose the slurry to temps above 95 degrees. You’ll be leaving the receptacles in place for five to seven days—enough time to allow a mold to form on the surface (hence the word “Save” on your cup!). Stir the mass right before you’re ready to clean the seeds. Pour the entire slurry mixture into a small, fine-mesh sieve. Run cool water over the mixture, gently pushing any mold and remaining pulp through the sieve. The openings of the sieve obviously shouldn’t be larger than the seeds. If you can’t push all the mold or pulp through the sieve, simply pick it out with your fingers. Continue this cleaning process until the seeds are free of any residue. This molding process is called “fermentation.” Tomato seed savers do this to slough off the slippery gel that surrounds the seeds. This gel is a germination inhibitor, so you’ll want it gone for next year’s seed sowing. Also, there are a few diseases that can be reduced or eliminated during the fermentation process (good bacteria battling with bad bacteria).
Dry the seeds by slapping them upside down onto a piece of waxed paper, parchment paper, or a waxed paper plate. Avoid using paper towels or non-waxed paper plates; these paper products will end up sticking to the seeds later. Again, write the variety name, the date, and “Save” on the surface you have slapped the seeds onto. Put these in a dry, protected area free of wind and rodents. Air movement is fine, but note that a strong wind can grab the paper or plate and send it flying, scattering your seeds—and hard work—everywhere.
Leave the seeds alone to dry for a week. They will have dried stuck together; simply rub them gently between your fingers to break them up, then store them safely in a plastic film canister, pill bottle, or another small receptacle that you can label and keep safe from mice.
Wherever you decide to store your seeds, keep them safe from vermin, excessive heat, and moisture. Don’t store in a metal garden shed, a greenhouse, or any other place that can heat up to levels above 100 degrees. Note: Carrying seeds and seed packets around in your vehicle can hurt them, too. If you’re parked, leaving seed packets in a hot car means you can accidentally kill them with the “greenhouse” effect.
Late blight is a dreadful disease of tomatoes. Its proper name is Phytophthora infestans. This is the fungus-like pathogen that caused the Irish Potato Famine. It can invade your tomatoes and other related crops very quickly in periods of high moisture and moderate temperatures (60 to 80 degrees).
Your garden may not experience high moisture in the form of summer rainfall, but high humidity, fog, and improper overhead sprinkler irrigation can also spread the disease. Late blight is carried on wind currents all around the world and comes down to infest crops via moisture when temperatures are between 60 and 80 degrees.
Be vigilant during high-moisture periods that consistently stick in this temperature range. Inspect your tomato foliage for symptoms of this terrible disease. The first symptom is a gray, fuzz-like coating in the crotches or nooks of your tomato plant leaves and stems. Those are the areas that hold water longer, allowing the pathogen to take hold and begin to kill the plant. This fuzzy gray coating quickly turns black. The black and its rot take over the plant, killing it. Meanwhile, the spores have broken away and start to infiltrate the rest of your garden.
You can prophylactically spray to prevent late blight during periods of high moisture and temps between 60 and 80. Preventative sprays are only effective when the entire plant is covered. These sprays help ward off the disease; however, once the plant is infected, even in a minor way, there is no cure. Note that temperatures higher than 80 and lower than 60 or dry conditions do not favor late blight, so spraying a preventative is not helpful at those times.
Share your bounty
If you simply have too many tomatoes and have maxed out your preserving efforts (canning, sauce making, dehydrating, freezing), then share your bounty with neighbors, your banker, your doctor’s office, and your kids’ school teachers, or take a big basket down to your local police department or fire department as a thank-you.
Drop some off at a homeless shelter or soup kitchen. There aren’t many places or folks who would turn down homegrown tomatoes!
August is no time to slack on your maintenance duties. We still need to keep up almost daily watering of tomatoes grown in pots, weekly fertilizing of tomatoes in pots, weekly spraying of worm casting tea and aspirin for all tomatoes, and bug checks.
If the mulch is looking thin or you’re noticing bare patches, re-mulch with a thicker layer. August is a hot, dry month, typically, and the soil will be vastly improved if you keep it consistently moist and cool with the mulch cover.