The Growth Stages of a Zucchini Plant

Zucchini are summer garden favorites, growing quickly and easily and producing such abundant crops that they inspire the old joke that you'll run out of friends before you run out of extra zucchini. After you sow your zucchini seeds into your garden, you will watch the plant grow, emerging as a tiny seedling and, within a few months, sprawling as a long vine across your garden, producing flowers and, eventually, fruits.

Hold a zucchini seed in your hand and you are holding the raw materials for one of your garden's largest and most productive plants. The zucchini's life begins with germination, when soil temperatures warm to about 70 degrees Fahrenheit, causing the seed to absorb large quantities of water. Water triggers the embryo to begin growing, and soon, it exceeds the tight confines of the seed coat and bursts free. The root emerges first, correctly orienting and anchoring the seed in the soil. Next, the primitive leaves, called cotyledons, stretch upward, pushing aside the soil and reaching for the light.

Zucchini grow in two forms: bush, or determinate, and vining, or indeterminate. Growth from a tiny seedling into these large forms requires rapid mitosis, a process during which cells make an extra copy of their genetic material and split into two cells. Growth occurs in a part of the plant called the meristem, which you can find at the growing end of a zucchini vine, the tips of the roots and in the nodes, points along the stem that develop into leaves and flowers. The ability of the zucchini plant to produce so many different structures from a single type of cell allows the plant to grow rapidly, producing edible fruits within a matter of a few months.

During the final stage of the zucchini's life, it concentrates its energy on producing seeds to ensure the survival of the next generation. When the days lengthen in midsummer, meristems along the vine grow into flower buds. Zucchini, like all members of the squash family, produce male and female flowers separately on a single vine and rely on bees to carry pollen from male flowers to female flowers. Once pollination occurs, the pollen grows into a tube that enters the ovary of the female flower and deposits sperm cells where they can fertilize the egg within. Each ovule within the ovary develops into a separate seed, and the wall of the ovary thickens into a fleshy fruit coat, the tasty green fruit that you recognize as zucchini.