Introduction to Vegetable Plants
Most plants are inedible, being much too woody and tough for human consumption. Vegetables are plants that have been developed to be eaten, but usually only a portion of a vegetable plant is edible. For instance, on the tomato plant we only eat the vegetable fruit - the tomato - but not the roots, stem or leaves. On the carrot we eat the taproot, - the carrot - but not the stem, seeds or leaves. In addition, we are normally required to eat a vegetable within a certain time frame, when the vegetable is said to be ripe or when it reaches a certain size or color.
Like humans, plants breathe and expel gasses, extract energy from food, are able to reproduce sexually (male/female), and their offspring inherit the DNA characteristics of their parents. But unlike any animal, plants can convert sunlight into energy compounds such as proteins, fats and carbohydrates, a process called photosynthesis. These energy rich compounds are the source of energy that fuels all animal and human life, and is one of the most amazing processes in nature. It is said that the dinosaurs were killed-off not because anything ate them, but rather because the plants they ate as a food source was destroyed.
The Importance of Plants
Humans and animals cannot produce the energy we need to live, so we relay on plants to supply this energy. We feed cows, pigs, steers, chickens, turkeys and other feed animals basic plant products, mostly grains such as corn. So the meat we eat is possible only because of plants and their ability to photosynthesize sunlight. Humans breath oxygen, and plants provide this as well, converting carbon dioxide that we expel, into oxygen that we breathe. They do this, again, through the miraculous process of photosynthesis. Plants also prevent the erosion of our soil recourses and moderate water loss into the atmosphere.
About one quarter of all prescription drugs contain plant products, making them an important source of pharmaceuticals. And adding greens and vegetables to your diet can help prevent the onset of obesity, cancer, diabetes and other medical maladies. Doctors tell us that no one has ever been harmed by eating too many fruits and vegetables, and vegetarians are known to live long, healthy and more disease-free lives than those who chock-up on meats, fats, cheese and butter.
Leaves are attached to stems normally via a stalk and are what we like to eat in many plants, such as cabbage, lettuce or spinach. Some leaves are poisonous, such as those of the rhubarb plant, while others are inedible, like those of the pepper plant.
Stems support the plant and transport water and nutrients from the roots to the leaves. Stems bear the buds, flowers and leaves on the plant and can take several forms. Some stems are very short, such as those of the cabbage. When you cut a cabbage in half, the white hard core in the center is actually a short stem (which connects to the roots of the plant). The leaves of the cabbage are what we eat, but the stem is what we normally cut-out. The stem of a tomato plant bears the flowers, which develop into the tomato fruit that we eat. The same can be said of a zucchini or melon.
Roots anchor the plant to the soil, absorb water and nutrients and store excess food. There are two types of roots: fibrous and taproots. Fibrous roots are small, thin and numerous, and are the most common. Vegetables that create fibrous roots are cabbage, tomatoes, peppers, squash and eggplants. Taproots are large, fat and few in number, and are less common. Vegetables that create taproots are carrots, beets, radishes, rutabagas and turnips.
Flowers are the reproductive organs of a plant and contain seeds for the next generation. Some flowers develop into vegetable fruits (vegetables), such as the flowers of the tomato, pepper, squash and pickle plants. These vegetables contain the seeds inside of them and are normally high in energy. Most gardeners dont know this, thinking that vegetables develop from leaves or stems. The vegetable fruit that we eat comes from the flowers of the plant.
Plant Parts We Eat
In some vegetables we eat their leaves, stalks or buds, while others we eat the taproots, seeds or vegetable fruits.
||Brussels sprouts (in the form of bud sprouts)
||Garlic, Green onions (Scallions), Leeks, Shallots and Onions.
||Broccoli and Cauliflower.
|Leaves and leaf stalks
||Cabbage, Chicory Collards, Cresses, Endive, Escarole, Florence fennel, Kale, Lettuce, Parsley and Spinach.
|Roots and taproots
||Beets, Carrots, Horseradish, Parsley, Parsnips, Radishes, Rutabagas, Salsify and Turnips.
|Seeds or seed pods
||Caraway, Corn, Dill, Lentils, Peanuts, Peas, Soybeans, Bush, Broad, Green, Lima, String and Sugar beans.
|Stems, spears or tubers
||Asparagus (in the form of a spear), Cardoon, Celeriac, Celery, Chinese cabbage, Jerusalem & Chinese Artichoke, Kohlrabi, Rhubarb, Seakale, Swiss and Ruby chard, and Potatoes (in the form of a tuber).
||Cucumbers, Eggplant, Peppers, all Melons, Pumpkins, Pickles, Zucchini, Summer/Winter Squash and Tomatoes.
Some vegetables are rather confusing and not so obvious. For instance, a potato is called a tuber, which is actually an enlarged stem. Many people think it is a root, because it grows underground, but is really a stem that will develop eyes that sprout additional stems and plants. Another one is Brussels sprouts, the small cabbages being really buds, not leaves, but we call them sprouts rather than buds.
Vegetable plants have a defined life cycle in which they germinate, grow into adult plants, produce flowers, seeds or fruit, and then die. Some vegetables are annuals, which means that all of the above take place during a single growing season, while many are biennials, which means that they germinate and grow into adults in the first year and then produce flowers and seeds the second. A small number are annuals, which are vegetables that grow for more than three years.
Example of annual vegetables:
Broccoli planted early
Radish planted early
Example of biennial vegetables:
Example of perennial vegetables: