Assoc. Editor's note: Consideration of family relationships, particularly between crops and weeds is important for disease and weed management, regardless of production methodology being used. This article is taken with permission from the Vegetable and Small Fruit Gazette, Penn State Horticulture, Vol. 9 #5.
Knowing which family a plant belongs to can be useful in making decisions about crop rotations for managing pests and soil fertility. Plants that are in a family are genetically related, so they share similar characteristics. As an example, members of the Cucurbitaceae, among other shared characteristics, have deeply lobed or divided leaves, separate male and female flowers on each plant (termed "monoecious" plants) with five fused petals, similar fruit types, and tendrils for climbing. Besides having similarities in appearance, plants in the same family often have similar susceptibilities to various problems such as diseases, insects, or nematodes.
In general, it is not recommended that a field be planted with members of the same family in succession to avoid the build-up of shared pests. Some crops should not follow members of other families either because of susceptibility to common pests. For example, strawberries (or other crops in the Rosaceae) should not be planted after members of the Solanaceae (and vice versa) because they are all susceptible to verticillium wilt. Keep in mind that various weeds also belong to these same families, and can also host the same pests. Knowing plant families can also be useful in determining appropriate pesticides to use, when warranted, as effects within families are often similar. This can apply to both wanted effects, and unwanted effects such as phytotoxicity to crop plants from certain pesticides.
Crops can be rotated to manage soil fertility. This is done by including crops in the rotation to improve the fertility status of the soil and rotating among heavy users of certain nutrients. For example, members of the Fabaceae can be grown to add nitrogen to the soil and many members of the Liliaceae are heavy users of potassium.
The table below lists several vegetables, herbs, fruit, cut flowers, cover crops and weeds by plant family. Plant family names can be easily identified because they end in '-ceae'; however, some families also have 'old' names which end in '-ae'. Old names as well as common names are included in the table. Note than some plants are listed in more than one grouping.
|Solanaceae||solanaceous crops; potato, tomato or nightshade family||peppers (bell and chile), tomatoes, potatoes, eggplant, tobacco, tomatillo||petunia, million bells||nightshade, jimsonweed, henbane, groundcherry, buffalobur, horsenettle|
|Brassicaceae||Cruciferae; brassicas; cole crops; cruciferous crops; mustard family||horseradish, cabbage, cauliflower, broccoli, kohlrabi, kale, Brussels sprouts, turnips, Chinese cabbage, radish, rapeseed, mustard, collards, watercress, pak choi, bok choi, rutabaga||stock, alyssum, candytuft||shepherd's-purse, field pennycress, yellow rocket|
|Cucurbitaceae||cucurbits; cucumber family; squash family||cucumber, melons, watermelon, summer squash, pumpkin, gourds, winter squash|
|Rosaceae||rose family, rosaceous plants||apples, peaches, apricots, nectarines, plums, strawberries, blackberries, raspberries, pears, cherries||multiflora rose|
|Fabaceae||Leguminosae; leguminous crops; legumes; bean, pea or legume family||beans, peas, lentils, peanut, soybean, edamame, garbanzo bean, fava beans, hairy vetch, vetches, alfalfa, clovers, cowpea, birdsfoot trefoil, black medic||various vetches, clovers, black medic|
|Poaceae||Gramineae; grass family||corn, wheat, barley, oats, sorghum, rice, millet, rye, ryegrass, sorghum-sudangrass, fescue, timothy||ornamental grasses||brome, wild oats, crabgrass, orchardgrass, barnyardgrass, quackgrass, fall panicum, foxtail, Johnsongrass|
|Polygonaceae||Knotweed family||buckwheat, rhubarb||knotweed, smartweed|
|Liliaceae||lily family; alliums (for members of the Allium genera)||asparagus, onions, leeks, chives, garlic, shallot||tulips, daffodils, hosta, hyacinth, daylily||wild garlic and onions|
|Lamiaceae||Labiatae; mint family||lavender, basil, marjoram, oregano, rosemary, sage, thyme, mints, catnip||salvia, Molucella (bells-of-Ireland)||mints, catnip, henbit|
|Ericaceae||heather or blueberry family||blueberries, cranberries||rhododendrons, azalea, heather|
|Chenopodiaceae||goosefoot family||spinach, beets, chard, sugar beets||kochia, lambsquarters|
|Apiaceae||Umbelliferae; carrot family||carrots, parsnips, celery, dill, chervil, cilantro, parsley, caraway, fennel||Trachymeme, Buplerum||poison-hemlock, wild carrot|
|Asteraceae||sunflower family; aster family, Compositae||sunflowers, lettuce, endive, escarole, radicchio, dandelion, Jerusalem artichoke, artichoke, safflower, chicory, tarragon, chamomile, echinacea, sunflowers||marigold, mums, zinnia, aster, Calendula, cosmos, Rudbeckia, Tithonia, Centaurea, Helichrysum, yarrow, Leucanthemum, echinacea, sunflowers||dandelion, Jerusalem artichoke, chicory, echinacea, thistles, knapweeds, cocklebur, yarrow, ragweeds, goldenrod, groundsel, galinsoga, sunflowers|
Originally printed in Virginia Vegetable, Small Fruit and Specialty Crops – May-June 2005.
Virginia Cooperative Extension materials are available for public use, reprint, or citation without further permission, provided the use includes credit to the author and to Virginia Cooperative Extension, Virginia Tech, and Virginia State University.
Issued in furtherance of Cooperative Extension work, Virginia Polytechnic Institute and State University, Virginia State University, and the U.S. Department of Agriculture cooperating. Edwin J. Jones, Director, Virginia Cooperative Extension, Virginia Tech, Blacksburg; M. Ray McKinnie, Administrator, 1890 Extension Program, Virginia State University, Petersburg.
August 17, 2009