As the days and nights grow cooler, so does the soil, and this slows the growth of plants. This is why most commercial greenhouses use heat mats to heat soil and stimulate growth. There are a number of ways you can achieve warmer soil without using electricity. Perhaps the cheapest is to plant in cinder blocks. These blocks collect heat during the day and then radiate it during the night. They also provide excellent drainage. These $2 blocks also work well as the walls of a raised bed, with or without mortar. I have planted lot’s of different starts in cinder blocks at zazu, and they have grown much faster than the ones I planted at the same time in the ground. I’ve also been experimenting with planting in pure compost or manure, which seems to work well. Starting this week, restaurant patrons will be able to pick their own lettuce before dinner for a salad with asian pears.