The Late Summer Garden: Tips for Specific Crops.

In August and September, you want to harvest high-quality produce from your productive summer crops, and get a healthy batch of fall crops going in the areas that are starting fresh. Here are some tricks I have learned to get a good stand of new seedlings in spite of the heat, and get the most out of your summer corn patch.

Getting lettuce to sprout in hot weather
Most lettuce has spotty germination in hot weather. (Just when you really want salad,) If the seeds have been stored in temperatures over 80, they can go into deep dormancy and be difficult to sprout. Two solutions:

1. Try crisphead lettuce varieties. Most of them have a different gene that doesn't restrain sprouting in hot weather.​
2. Keep your seeds in the refrigerator, or at least put them there for a week before planting. This can help with spinach, beets, chard, carrots, and other spring-loving seeds as well. Use a moisture-proof container and make sure the seeds stay dry. A quart canning jar or a plastic food-storage container with a good seal works well to store your seed packets.
3. Sow the seed in the evening. Choose a well-watered bed with shadecloth over it. Or sow in a flat in a cool shady place. If your home is cooler than outside, keep your flats there, with a cool light source like a fluorescent light.​

Getting a good stand of root crops
Root crops are winter comfort food. They aren't demanding, either. Ordinary garden soil with no extra fertilizer should do. The hard part is getting them started. They need to get going while the weather is still hot, or they won't be big enough when cold weather comes and growth stops. Their seeds take longer to sprout than greens do.  You have to keep the soil moist for a long time so the seeds don't dry out and die. This can be a challenge. Try this:

1.  Carrots, beets, and parsnips all have growth inhibitors on them.  This is nature's way of preventing them from sprouting when there is not really enough water to support growth. Soak the seeds overnight. Then rinse them well and plant immediately. Turnips and rutabagas are faster sprouters and need no soaking.
2. Keep the soil moist until the seeds are up and the little plants established. There are lots of ways gardeners accomplish this--with frequent watering, shadecloth; very light mulch; a top dressing of sand to prevent evaporation and crusting; temporary barriers to wind and sun made from cardboard, wood, or lawn furniture. Some folks lay cloth or cardboard on the ground to keep it damp. If you do that, you must check on it often so they don't get crushed. Weed well before planting and after the little plants are up, so they don't get overwhelmed. After that, it is usually easy.​

Growing well-filled ears of corn
For some reason, I never see cucumber beetles damaging my cucumbers, or any other cucurbit. What I do see them doing is eating cornsilks. Now this is a big problem because the silk is the pollen tube of the corn ear. If pollen can't go down that tube to pollinate the ear, kernels won't form. So check your ears; if the silks are cut off short, or missing, you need to go get cucumber beetle traps. They are sticky like flypaper and have a pheromone that attracts the beetles.

When to harvest sweet corn?
It is not as straightforward as a tomato. There is no visible sign when the sugars that make it sweet are fully developed, or when they (very quickly, alas) turn to starch and lose flavor. Once you see shriveled silks at the tip of an ear, watch it daily. When the ear is well-filled, feel the tip to see if it feels pointed under the husk or if it has filled out into a more rounded or blunt shape. The husk should still be green, and the silks should be brown and dry. Eventually, when you think it may be ripe, you can peel back the husk enough to check the kernels themselves. Pop one with your fingernail. If it has clear juice, it's not really ready (but don't throw it away, its just not as sweet.) If the juice is milky, it is JUST RIGHT. If it is pasty or gummy, it is past its prime but still edible. Once you have peeled back some of the husk to make this check, watch the ear carefully for insect damage.