Final answer:
Bare root plants must be planted when they are dormant, typically during the fall or early spring when the plant is not actively growing, to ensure the best chance for survival as they have specific requirements for their roots, foliage, and the dormancy of their seeds.
Step-by-step explanation:
The correct answer to the question about when bare root plants should be planted is d. Must be dormant when planted. Bare root plants are typically those that have been dug up and stored without soil around their roots. They are commonly used in horticulture and must be handled carefully to ensure they survive transplanting. They must indeed be dormant when planted to increase the likelihood of successful growth when the right conditions return.
Bare root plants depend on factors such as their root structure, foliage, and transpiration for survival. They often require deep roots to stabilize the plant and assure access to nutrients. Fleshy leaves and sunken stomata help to reduce water loss, while seeds may need the ability to remain dormant for extended periods until conditions are suitable for germination. Aspects of plant physiology like why some plants bloom in different seasons, how they respond to light, and mechanisms of dormancy and ripening can be connected directly to AP courses in biology.
For most bare root plants, the preferred conditions for planting are during fall or early spring when the plant is not actively growing to avoid damage to delicate structures. This is opposite to plants like tubers, which are planted in the spring and harvested in the fall post the annual shoots dying off. Understanding the growth cycles and needs of plants like these is crucial in botany and horticulture.