What is an annual, a perennial, and a biennial?
First, it is important to realize that a grower may treat a plant's status as annual, biennial, or perennial depending on the growing conditions. A biennial may be grown as an annual, for example.
An annual is a plant that completes its life cycle, from germination to seed production, within one year. Annual plants provide us most of our vegetables in zone 5.
A perennial is a plant with a life cycle of two or more years. The perennial may flower in the first year, die back during winter, and then grow back from its rootstock the following spring. In the lower growing zones, perennials may be grown as annuals. Perennial seeds can be started as soon as you receive them from your seed suppliers under indoor lights. There are very few vegetable perennials. Asparagus, rhubarb, and Jerusalem artichoke are perennial vegetables. Many herbs are perennials.
A biennial is a flowering plant with a two-year life cycle. In the first year the plant will develop its root structure, leaves and stems. It then requires a winter cold cycle before flowering in the next spring or summer cycle.
What seeds need to grow into seedlings ( heat, light, humidity, a bit of a breeze ).