By mid-August, a lot of growers are burnt out. The hot sum, the humidity, the pests and the diseases affecting plants all play a vital role in making gardeners feel like it's time to throw in the towel. However, other gardeners are pulling out diseased or spent plants and have some room to plant new things.
Generally speaking you want to look up your first frost date and work your way backwards. In zone 7b, the first frost date is November 17th. I'm not sure that we can get to the middle of November with only a light frist so I will use November 1st as my frost date to be a little cautious. As of August 9th, that gives me approximately 83 days of growing non-frost tolerant crops. Hence, knowing the days to maturity for the varieties you are planting gives you a good chance of harvesting some additional fall and even some summer crops.
Some varieties of spinach, kale and lettuces are frost-hardy and can grow through the winter if you don't have a really hard frosts. I had spinach and kale surviving through a mild winter and even some snow sitting in a pot that was completely forgotten. They were putting out new growth early in spring without me having to do anything. If you are thinking about what to plant in August, here are some ideas.
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- Swiss Chard
- Arugula
- Green beans
- Some varieties of corn
- Radishes
- Turnips
- Spinach
- Lettuce
- Collard Greens
- Brasicas like Cauliflower, Cabbage, Broccoli, Brussel Sprouts
- Kale
- Cucumbers
- Dill
- Rosemary & Lavender
- Both of these herbs can take a good amount of frost but needs the warm soil of August to get established.
- Coriander / Cilantro
- Parsley
- Carrots
- Beets
In addition, it's also possible to grow a lot of other things and extend the growing season if you're using a greenhouse but I'm assuming you're growing in pots, raised beds or in-ground.