Classification of Vegetable Crops
Updated: May 8
Webster's dictionary refers to vegetables as "any plant" whose parts are used as food. To put it quite plainly, there are about 10,000 plant species that are used as vegetables. Of those, only about 50 are commercially "important". To help identify and catalogue the large volume of information these plants provide, a systematic method for grouping different plants has been created.
Broadly there are five methods of classifying vegetables, but their value depends on its usefulness to the person using it.
- Hardiness or Temperature
- Life Cycle
- Plant Part Used
Botanical classification involves grouping of plants into 7 mandatory ranks (there are more but aren't mandotory): Kingdom, Division, Class, Order, Family, Genus and Species.
Out of these classifications, the Genus and Species constitute the scientific name. Scientific names are the most widely excepted but are only useful for students of Olericulture and academicians but is of little value to a grower.
All vegetable crops requiring similar cultural and climatic requirements.
Cole Crops: belong to the Brassicas family, these crops are winter season and transplanted.
These include: Cauliflower, Cabbage, Chinese Cabbage, Sprouting Broccoli, and Brussels Sprouts, etc.
Leafy Vegetables: these crops are directly seeded.
These include: Spinach, Leaf Beet, Coriander, Amaranth, Swiss Chard, etc.
Salad Vegetables: these crops are mainly eaten raw.
These include: Lettuce, Celery, Chicory, Parsley.
Bulb Vegetables: belong to the Alliaceae family, these crops grow just below the surface and produce a fleshy bulb, and a leafy shoot above ground.
These include: Onions, Leeks, Garlic, etc.
Root Vegetables: these crops have a fleshy underground structure and are direct seeded winter season crops.
These include: Radish, Carrot, Turnip, Beetroot, Parsnip, Rutabaga, etc.
Cucurbit Crops: belong to the Gourd family, these crops have tendrils, fleshy fruit and are direct seeded summer season crops.
These include: Melons, Gourds, Cucumber, Pumpkin and Summer Squash.
Perennial Vegetables: these crops grow for more than two years, and can grow up to 15 years.
These include: Asparagus, Artichoke, Chayote, Ivy Gourd and Pointed Gourd.
Solanaceous Crops: belong to the nightshade family, most these crops are perennials, but treated as annuals and are summer season transplanted crops.
These include: Tomato, Chili, Bell Pepper and Eggplant.
Tuber Vegetables: these crops are vegetables which grow underground on the root of a plant. Tubers are usually high in starch.
These include: Potato, Sweet potato, Taro, Cassava/Tapioca, Yams
Pea and Beans (Pod Vegetables): belong to the pea family, these crops are legume vegetables and are directly seeded.
These include: Pea, French Bean, Dolichos Bean, Broad Bean, Cluster Bean, Lima Bean, Winged Bean and Cowpea.
Hardiness or Temperature
Hardiness or Temperature classification is probably one of the earliest attempts to group plants. It is based on the ability of crop plants to tolerate frost and is either classified as warm- or cool-season plants. This classification helps growers and farmers know when to plant these crops.
Hardy or Cool-Season Crops are:
- Adapted to growing in 10-18C monthly temperatures.
- Crops that can tolerate frost. Essentially cold or cool season crops.
Frost is defined as ice crystals that form on the surface of vegetables, while;
Freezing is ice formation inside the plant tissues.
- Further divided into:
Hardy/Tolerant vegetables, which include asparagus, Brussel sprouts, cabbage, collard, kale, garlic, leek, onion, parsley, pea, radish, spinach, turnip, etc.
Semi-Hardy/Semi-Tolerant vegetables, which include carrot, cauliflower, celery, globe artichoke, lettuce, leaf beet, parsnip, potato, etc.
Non-Hardy or Warm-Season Crops are:
- Thrive best under high temperatures, 18-30C.
- Often tropical origin and are perennial plants, but are grown as annuals in regions that get cold.
- Crops that are intolerant to frost and are sensitive to chilling. Essentially warm season crops.
Tropical and subtropical crops are prone to chilling injury, not the same as freezing injury.
Chilling injury occurs when the vegetables are exposed to 10-13C.
- Further divided into:
Tender/Sensitive vegetables, which include chilli peppers, tomatoes, corn and snap bean, etc.
Very Tender/Very Sensitive vegetables, which include amaranth, okra, bell and chilli pepper, Lima and cluster bean, summer squash, pumpkin, cucumbers, etc.
How long a plant last can be classified into three groups: annuals, biennials and perennials. This classification is important for the growers and farmers.
Annuals: complete their life cycle in a single growing season.
Biennials: complete their life cycle in two growing seasons. First season it has vegetable growth, the second it goes to seed to reproduce.
Perennials: they grow for more than two years, and can grow up to 15 years.
Plant Part Used
This classification is important from the consumer and post-harvest handling point of view. The important thing to know for consumers is that:
- Vegetables are perishable, they cannot be stored for long-periods.
- After harvest they need to be cooled down and stored under ambient temperature to preserve the quality.
- Tubers and bulbs can be stored at room temperature for a period of time without loosing quality.
Fruits: Tomato, Eggplant, Chilli, Bell Pepper, Melons, Cucumber, Pumpkin, Summer Squash, Indian vegetables, Choko, Courgette and Scallopini, Okra, etc.
Seeds: Pea, Corn, Snap Pea, Snow Pea, Beans, etc.
Flowers: Broccoli, Cauliflower, Globe Artichoke
Leaves: Cabbage, Lettuce, Spinach, Leaf Beet, Amaranth, Fenugreek, Fresh Herbs, etc.
Stems: Asparagus, Celery, Rhubarb, Kohlrabi, etc.
Tubers: Potato, Sweetpotato, Cassava, Taro, Kûmara.
Roots: Celeriac, Radish, Turnip, Carrot, Beetroot, Ginger, Yam, Rutabaga, Parsnip, Swedes, etc.
Bulbs: Fennel, Onion, Shallot, Spring Onion, Garlic, Leek, etc.
Photo from Understanding Food Principles and Preparation