Yes – as posted earlier, you can start cool weather crops in the summer – middle of a heat wave in fact, as long as you can keep the soil moist. By covering the soil with a light mulch and watering enough to keep the soil from crusting, the seedlings have the right environment to sprout. Be sure to move the mulch (but don’t remove it, just push it in between the rows) so the plants don’t get shaded, or stay too moist. Here, we have started broccoli during our 95+ degree weather. The carrots are starting to show up too! Keeping the cooler weather crops cool will be a matter of shading them with some shade cloth or moving a potted plant nearby, such as a comfrey plant or possibly moving the box under one of the patty pan squash canopies for now, moving them out when the weather breaks. Lettuce can be started in the heat of the summer too, though even when shaded it does tend to bolt, causing the leaves to become bitter.
The Hack: Start cool weather crops in the summer and keep them growing by
- planting them in containers, keep them moist,
- keep them shaded during the hot spells, and
- remove the mulch at the first sign of sprouting