Living things respond to their environment. Response to stimuli is an important characteristic of life. Anything that causes a living organism to react is called a stimulus (plural is stimuli) Stimuli can be external or internal. For instance, if you feel like going to the bathroom, it is an internal stimulus that is controlled by the brain.
Planting leafy green vegetables is easy, but itâs all in the timing. Knowing when to plant greens (such as spinach, kale, and lettuce) depends on your climate and if the leaf vegetables are heat- or cold-tolerant. Greens grow year-round in areas with mild summers and winters, such as the West Coast. For most other areas, spring and fall are the best times to grow greens.
Turnip greens are easy to grow in any well-drained soil. Set out turnip green plants 2 to 4 weeks before the last frost in spring and from late August to October for a fall crop in most areas. In zones 9 and 10 they can be planted throughout fall and winter. Like collards, kale, and other greens, turnip greens need to grow fast to produce nice, tender leaves. They arenât too fussy about soil, growing well in a soil pH of 5.5 to 6.8, and doing okay even in poor sandy soil.