All in the Family
Like all plants, every vegetable you eat is part of a specific plant family. Knowing your plant families can help with your planting and harvesting and with your disease and pest control. Organic gardeners and farmers often practice crop rotation. In crop rotation, plant families are cycled from one bed to another (best results occur when families are grown in a specific bed only once every seven years). This gives pest- and disease-susceptible plant families a better chance and ensures that the soil will not be depleted of the same nutreients year after year (since each plant family takes different needs different nutrients from the soil). Plant rotation seems complicated at first but once the families are learned, it can become a simple way create the best vegetable production possible. Containers can be used to add bed space to a small garden and keep the rotation going!
History
Carl Linnaeus (1707-1778) revolutionized botanical nomenclature and classification by setting out to name and organize all plants (and animals) known to him. In 1867, Botanists from around the world met in Paris to further standardize the names and classifications of plants, using Linneaus' text as a base. Since that time there have been changes, additions and evoltuions in the standardized text as more is learned about botanical relationships of plants (i.e. just because they look alike, doesn't mean two plants are related). Today, gardeners can become botanical and scientific experts or just stick to the local common names of the plants in their gardens. If you are planning on growing veggies though, there is a real benefit to knowing which family you're working with and its unique characteristics and needs. Note that how plant families are named varies from one family to the next but they will all end in the Latin suffix -aceae, meaning "belonging to".
Alliaceae
"The Onion Family"
Onions Chives Leeks Garlic Shallots
All vegetables in the Alliaceae family have bulbs. Some bulbs are underdeveloped (like leeks) and some come in bulk (like garlic). They grow naturally in temperate zones and many varieties are found in the wild. The family name derives from the Latin word for garlic but the bulb veggies have also been placed in the Amaryllidaceae and/or the Liliaceae family because of similar characteristics among the plants.
Members of the Alliaceae family are fragrant (and can be pungent), due to their sulfur content. They generally have long and hollow leaves and it can be difficult to tell them a part until flowers bloom or the harvest approaches.
Apiaceae
"The Parsley Family"
Parsley Carrots Parsnips Celery Cilantro Dill Fennel Cumin Coriander Angelica Poison hemlock
The Apiaceae name derives from the Latin for parsley and celery. This family of mostly annuals is known for being aromatic and for their characteristic dome or bell shaped shoot of feathery leaves. This shape gives them their alternative name, Umbelliferae. They are native to temperate areas but varieties such as carrots and parsnips can be keep in the cold early winter ground until you want to harvest them.
Asteraceae
"The Sunflower Family"
Lettuce Artichokes Sunchokes Dandelions Sorrel Endive Rhubarb
The Asteraceae family is very large but includes only a few edible varieties. This family is also called Compositae because of its seemingly large flowers that are actually made of many smaller flowers (easily seen in dahlias and asters). Lettuce is the most widely grown vegetable in the family but artichokes, which are tall and decorative perennials, and sunchokes (or Jerusalem artichokes), root crops that can be baked and eaten as a starch, are popular as well. Many leaves in the Asteraceae family produce a bitter milk-sap that is used in herbal remedies for its soporific effect.
Brassicaceae
"The Mustard Family"
Cabbage Cauliflower Brussel sprouts Kale Broccoli Arugula Mustard greens Radishes Turnips
Many of our most common veggies come from the Brassicaceae family. The plants in this family are grown for their leaves. Brassicaceae, originally found around the Mediterranean, have been through some selective breeding from which the cabbage gave way to the both brussel sprouts and cauliflower.
Brassicaceaes are often called by their more ancient name, Cruciferae, referring to the cross-like image of the four petaled flowers of this family's flowers. They are also humorously called the "clubroot" family because of their susceptibility to the disease, all the more reason why plant family rotation is a good idea. These veggies are hardy in the heat and cold.
Chenopodiaceae
"The Beet Family"
Beets Spinach Swiss chard Quinoa
The Chenopodiaceae gets its name from the Greek roots for goose (cheno-) and foot (pod-), making reference to the goosefoot shape of the leaves. You may also find these plants listed under name Amaranthaceae which means "unfading in color", referring to their vibrant leaves. Chenopodiaceae grow in temperate zones and are a small family of vegetables, the most well known are spinach and beets and swiss chard, which is (botanically speaking) an underdeveloped beet root with tasty leaves.
Cucurbitaceae
"The Gourd Family"
Squash Pumpkins Cucumbers Melon Zucchini
Veggies in the Cucurbitaceae family grow quickly, in climbing or sprawling tendrils. Their fruit also expand relatively quickly and are filled with a water based sap. They can get so big that this family is known to grow the biggest fruit in the world! Cucurbitaceae do well in temperate and tropical zones and several varieties, such as pumpkins, are native to North America.
Fabaceae
"Pea Family"
Snow peas Shelling peas Green beans Black bean Soy beans Lentils Crimson clover
Solanaceae
"The Nightshade Family"
Potatoes Tomatoes Peppers Eggplant Tobacco
The Solanaceae family gets its name from the Latin solacum (nightshade). Many plants in this family have toxic leaves or berries (in fact, the only toxic free part of a potato is the tuber!). Solanaceae are tropical perennials but are grown as annuals in temperate zones. Certain varieties are temperature sensitive, when growing peppers for example, the hotter the region, the hotter your peppers will be! The Solananceae family is large and many of its veggies now serve as staples in diets around the world.
Now that you know...
Crop rotation in your garden doesn't need to happen overnight but it is a good goal to have in mind when designing your beds and it is an important part of growing the healthiest veggies you can. Please note that if you are still worried about the bed space needed to accomplish crop rotation, you could consider companion planting and plant two compatible families together in one bed, maximizing your space and the needs of your plants!
Resources
An Encyclopedia of Country Living Guide: Growing Your Own Vegetables by Carla Emery and Lorene Edwards Forkner
Stearn's Dictionary of Plant Names for Gardeners by William T. Stearn
The Vegetable Book by Colin Spencer