University of Nebraska - Lincoln DigitalCommons@University of Nebraska - Lincoln

Historical Materials from University of Nebraska-Lincoln Extension Extension

2000

EC00-1207 Growing , , and

Susan Schoneweis University of Nebraska-Lincoln

Laurie Hodges University of Nebraska at Lincoln, [email protected]

Loren J. Giesler University of Nebraska-Lincoln, [email protected]

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Schoneweis, Susan; Hodges, Laurie; and Giesler, Loren J., "EC00-1207 Growing Onions, Shallots, and Chives" (2000). Historical Materials from University of Nebraska-Lincoln Extension. 2012. https://digitalcommons.unl.edu/extensionhist/2012

This Article is brought to you for free and open access by the Extension at DigitalCommons@University of Nebraska - Lincoln. It has been accepted for inclusion in Historical Materials from University of Nebraska-Lincoln Extension by an authorized administrator of DigitalCommons@University of Nebraska - Lincoln. University of Nebraska Cooperative Extension EC00 -L207 -B Growing Onions/ Shallots, and Chives

Susan Schoneweis, Extension Coordinator for Environmental/Home Horticulture; Laurie Hodges, Extension Specialist-Horticulture; and Loren Giesler, Extension Plant Pathologist

The common ( cepa) is the most popu- often indicates that mechanical damage or decay has lar and widely grown A1lium in Nebraska home gar- occurred. Heat destroys alliinase, so whole boiled on- dens. Many members of the onion family (Alliaceae) ions tend to have little flavor because the flavor precur- are used in flower gardens because of their interesting sors have little chance to react with the enzyme. flowers and foliage, but here we're going to focus on the onion as a crop. Types of Onions Or:rions are thought to have first been domesticated in the mountainous regions of Turkmenia,IJzbeckistan, Tajikstan and northern Iran, and have been cultivated Onions are often grouped according to taste. The for more than 5,000 years. As people two main groups are the strong-flavored types (American) moved all over the world, the and the mild types (European or Bermuda). onion and its relatives in Generally, the more pungent onions produce the Allium genus or that are smaller and have a firm or Alliaceae families dense texture and a better keeping moved and quality than the milder, sweeter adapted to their onions. Each type new homes. On- has three dis- ions, and tinct colors - other have yellow, white, been used through- and red. Red out history for both onions have a culinary and medicinai deep red to pur- purposes. Scientists plish-red skin found that the various sul- which makes them fur compounds contained attractive in salads or in onions and that wherever raw onion give them their distinctive rings are used. Sweet on- flavors also have anti-mi- ions, such as the Vidalia crobial and anti-fungal and Walla Sweets, are low properties, giving valid- in sulfur compounds, but ity to their historic me- their flavor may be altered dicinal value. by the soil sulfur level. Whenfreshoniontis- Onions also may be sue is damaged, flavor grouped according to the du- precursors react with the ration of light required to trig- enzyme alliinase and the ger formation - short, flavors and aromas de- intermediate, or long-day on- velop. This is why whole ions. Generally, a short-day onions do not have an odor onion will form bulbs when the until they are damaged. The pres- day length is between 10 and 11 ence of an odor from intact alliums hours long, conditions occurring

Issued in furtherance of Cooperative Extension work, Acts of May 8 and June 30, 1914, in cooperation with the U.S. Department of Agriculture. Elbert C. Dickey, Interim Director of Cooperative Extensiory University of Nebraska, Institute of Agriculture and Natural Resources. DU MNE university of Nebraska Cooperative Exteroion ed ,:i5.,il:,ilT'Jilil:'S:;:i*5",::X*'f,lTnation policies of the university of Nebraska-Lincoln in Nebraska in early February. Long-day onions require They are then harvested in the summer and stored for a minimum of 14 hours of daylight before bulbs form. replanting the following spring. The main reason to use In Nebraska, daylight hours exceed the long-day mini- sets is for earliness or to allow mature bulb develop- mum by early May. Since the size of the bulb is directly ment in areas with short growing seasons. Usually related to the number of leaves formed prior to bulb onion sets are labeled by color, not specific cultivar. Sets initiation, long-day or intermediate-day onion culti- can be used for green onions (also called scaliions) or vars are best for Nebraska. can be left to grow for mature storage bulbs. Green Each onion cultivar within a photoperiod group onions can be pulled when plants are 6 inches or taller. (Iong-, short-, or intermediate-day) needs a specific There are also cultivars to grow from seed that will number of hours of daylight to induce bulbing. Once the produce a true bunching onion or that does not daylength (photoperiod) requirement is met, other fac- form a bulb. tors can reduce leaf size and result in premature bulb One disadvantage of planting onions from sets is formation or smallbulbs. These factors include drought their tendency to bolt (form seed stalks) and bloom. To stress, hail damage, insect damage, close spacing, and reduce bolting, sort and select small onion sets, 7/2 to weed competition, arnong others. Although short-day 1/3 inch in diameter from the larger sets. Plant the onions, such as the onion cultivar "Granex33" grown in larger sets (over 3/4 inch diameter) for early harvests of Vidalia, Georgia or the 1015Y can be grown in green onions as they are more likely tobolt if the young Nebraska, it is necessary to plant sets in very early shoots are exposed to prolonged temperatures below February and grow them rapidly to obtain large onions. 45.F. Some Nebraska gardeners have grown these success- Plant onion sets one to tlvo inches deep, close fully by using black plastic mulch or occasionally with- together and thin to 3- to 4-inches apart as r-ou han est out mulch, but it can be a challenge in our climate. green onions. If you don't pian to hart'est green onions, Most cultivars adapted to Nebraska conditions are the initial spacing should be 3 to -1 inches betu'een sets. fairly pungent and generally keep better than the mild, Rows should be 16 to 24 inches or more apart depend- sweet onions produced in the spring. The cultivars used ing on the method of cultivation. For rvide rou'plant- as storage onions are yellow and fairly pungent. The ing, plants or sets are placed on 3 to $inch centers. European or Bermuda onion cultivars are mild and Onions are ideal for wide row planting, but keep in several long- and intermediate-day cultivars are avail- mind that weeding then must be done br- hald. able, such as Sweet Spanish, Sweet Sandwich, Ring- master, and the Walla Walla Sweet. These do not store Plants well but are fine for use within a month or so of harvest. Onion plants often are produced in the south from Growing Onions seed planted in the fall and are usuallv bundled in the field in groups of 50 to 100 plants. Onion. lrom trans- Onions may be grown from seed, sets or trans- plants and seed usually do not form flou'er stalks the plants for use both as green onions and dry bulbs for first year. Garden stores may sell packs of locallr- grown storage. Using onion sets is the easiest way to grow a transplants or you can grow them under plant Lights by crop, followed by transplanting and direct seeding. starting seed in early February. Unlike sets, bundles of Onions are adapted to a wide range of temperatures onion plants are identified by cultivar so vou can choose and are frost-tolerant. Early spring planting is essential the type you want. Garden centers often sel1 short-day because best growth occurs when cool temperatures cultivars as well as long-dav srveet and (55'F to 75'F) prevail and several leaves can develop storage onions. For best yields of short-dav cultivars, bef ore bulbing begins. Nebraska gardeners should note transplant them as early as the soil can be rvorked, iate the size, shape and use as described in seed catalogs and February or early March. If transplant roots seem dry, select intermediate- or long-day cultivars when grow- trim them slightly and soak in tepid water for a few ing from seed or transplants. Short-day onions, which hours to re-hydrate them before planting. Set the base often are available as transplants in garden stores, must of the plants 1 to 2 inches deep and 3 to 4 inches apart, be planted very early in order to produce well. lightly firm the soil, and irrigate. Onions gron, w,ell when grown on raised beds mulched with black plastic Sets and using drip irrigation. The plastic mulch not only controls weeds but also raises the soil temperature for Onion sets are small onions grown from seed with more rapid growth and development. Cut holes in the the growth arrested so that it can resume at a later time. plastic, spacing the holes about 3 inches apart. The set Sets often are produced by planting a short-day onion or transplant is then planted in the hole. cultivar under long-day conditions to induce early bulbing. They are planted very thickly to limitbulb size. Transplants Cultivar Color Comments Early Harvest Yellow Medium round to flat Onion transplants can be easily grown indoors. Use shape a pasteurized planting mix of equal parts by volume of Early Yellow Globe Yellow More pungent flavor, good vermiculite, sphagnum peat, loam garden soil and keeper perlite. Seed of short-day cultivars started indoors in Downings Yellow More pungent flavor, good keeper ]anuary and transplanted to the garden in mid-March Ebenezer Yellow or white should produce a harvest in Long-day cultivars ]une. Chieftan Yellow can be started in mid-February and set out in late March Fiesta Yellow to mid-April. They will be ready to harvest in August to First Edition Yellow Large bulbs, bronze skin, September. Sow the seeds thickly and keep at 70. to good flavor, good keeper 72'F. As soon as seedLings emerge, place in a sunny Buffalo Yellow Large bulbs, good storage window or under a fluorescent light for 10 hours per Bullseye Yellow Large bulbs day. Harden seedlings for about two weeks by gradu- Golden Cascade Yellow Large bulbs ally exposing them to cooler temperatures and direct ol6 Yellow Very large bulbs, poor sunlight. Transplant them with 3- to 4-inch spacing in keeper all directions between plants. Cache Yellow Medium to large bulbs, good keeper Norstar Yellow Medium, good storage Seed onion, light brown skins Prince Yellow Medium, good storage Direct seeding of long-day cultivars may be done in onion, longer time to early spring. Since onion seeds will germinate in soils maturity than Norstar, rich darker 40'F or higher and the best seedling growth tempera- brown skins ture range is from 68. to 77"F, seeds planted in March Bermuda Yellow or white Small, flattened, mild and April in Nebraska can yield well. flavor, poor keepers Seeds should be sown 1 /4 inch to 3 /4 inch deep and Sweet Spanish Yellow or white Large bulbs, mild flavor, 2 to 3 inches apart in clay and clay-loam soils and fair keeper slightly deeper in loam to sandy soils. Seed can be Bennie's Red Red Large bulbs with mild planted singly in rows or broadcast over rows or beds flavor, pink to white interior color, poor keeper 1,2 to 24 inches wide. Onions can be slow to emerge, so Red Burgundy Red Large bulbs with mild sprinkle a few radish seeds in the row to mark the flavor, poor keeper location and help break any soil crust. Harvest the Ruby Red Small, flattened, mild radishes and thin the onions at the same time, leaving flavor, poor keeper 3 to 4 inches between onion plants. If left crowded, you Candy Yellow Intermediate day length can produce small bulbs for boiling, pickling or pearl with early maturing large onions. bulbs with a sweet, mild The main disadvantage with wide rows is that flavor. weeding between plants must be done by hand rather than with a hoe and if the ohions are left too crowded they will not form large bulbs. Onion Nutrition and Fertilization

Cultivars for Nebraska Unlike most plants, onion roots rarely branch and do not have root hairs. Compared to other crops, their root systems are considered to be small and shallow There are hundreds of onion cultivars and several and compete poorly with weeds. Therefore, it is impor- dozen of these are available home to gardeners tant to keep them weed-free and cultivate carefully so through seed catalogues, especially if you are inter- the roots are not damaged. ested in growing onion transplants or directly from Because of their shallow, coarse roots, onions do seed. Select cultivars that are appropriate for your not obtain soil nutrients as efficiently as other crops. It intended use cooked or fresh, winter - storage or is not necessary to fertilize onions until rapid growth is seasonal use, etc. and then evaluate them under your seen in the late spring. Then, a few light applications of growing conditions.- An assortment of seed catalogues nitrogen are better than a heavily fertilized bed, espe- can be found in NebFact 92-80, General and Speciatty cially in sandy soils where nitrogen is easily leached. Be Mail-Order Seed Sources, available through University careful not to over-fertilize or fertilize too late in the of Nebraska county extension offices or on the Intemet season. Onions tend to develop thick necks, be soft and at http : www. / / ianr.unl. edu / pubs / horticulture / not store well when over-fertilized. Generally, long- nf80.htm. The following includes list a few of the onion day onions in Nebraska should not be fertilized after cultivars that do well in Nebraska. the first week of July to allow the plant time to mature before frost. Onions grow best in a loose, well-drained soil with Onions must be cured if they are to keep well in plenty of organic matter. A soil pH of 5.0 to 6.5 is best. storage. Cure onions by placing them in a warm, well- Heavy clay or silt soils can be loosened by adding ventilated area until the necks are thoroughly dry. If organic matter. Using raised beds will improve drain- you have only a small crop of onions for storage, twist age and the soil will warm earlier in the season, promot- the leaves of each bulb a few times to pinch off the neck, ing growth. Organic matter also canbe added to sandy or cut the leaves 7 7/2 nch above the bulb to hasten soils to improve their water-holding capacity. Use soil closure of the necks. This will reduce moisture loss and test results as a guide for lime and fertilizer applica- help prevent decay organisms from entering through tions. Arrangements for soil testing canbe made through the neck. your local University of Nebraska Cooperative Exten- With warm temperatures, good air circulation and sion office, Fertilizers of a 1,-2-2 ratio (5-10-10, for low humidity, curing should be completed within two example) are good for onion production as they pro- weeks after harvest. After curing, onions are best stored mote good bulb development. in a very cool (close to 32"F), moderately dry area in After bulbing begins, high temperatures and low ventilated containers. relative humidity extending into the harvest and curing If you wish to hang your crop, do not trirn the tops, period are desirable. A constant, moderate supply of but braid them with a cord for reinforcement. Other- moisture while the bulbs are expanding is necessary for wise, place the onions in mesh bags, old nylon stock- good quality bulbs. Onions that suffer a growth check ings, or slatted boxes. Do not store onions in plastic or may produce double or splitbulbs, reducing the quality paper sacks or solid-sided boxes because these restrict of the crop. A light mulch will help conserve moisture needed air circulation. for uniform growth. Apply 1 inch of dry grass clip- pings, ground corn cobs or other mulching material Weed Control after sets or transplants are planted or seeds have germinated and plants are several inches tall. Do not Dense weeds in and around the garden not only rob mulch heavily or hill soil around the necks when culti- the crops of moisture, light, and nutrients, but also can for the vating as this will encourage stem and neck rot. Provide harbor insects and create an ideal microclimate consistent moisture, especially after bulbs begin enlarg- development of many diseases. Eliminate young weed ing in earlyJune,but stop irrigating when the topsbegin seedlings with shallow hoeing or cultivating. Always to fall over in August. pull or mow weeds around your garden area before they set seed. For large plantings, there are a few Harvesting, Curing and Storage herbicides which can be used. Pre-emergence herbi- cides kill weed seedlings before they emerge from the soil. Examples of herbicides that can be applied to the Harvest onions when about two-thirds of the tops soil to or at the time of planting include DCPA have fallen over and dried. Handle carefully to avoid prior (Dacthal) and trifluralin (Preen or Treflan). Grasses bruising and reduce storage rots. There is no truth to the after they emerge by applying old belief that one should break over the green onion may be controlled fluazifop-P-butyl (Grass-B-Gone, Fusilade 2000) or tops to make the onion bulbs larger. The bulb is stored sethoxydim (Poast or Poast Plus). Always read, under- food that is transported from the leaves. If the leaves are stand and follow label directions before using pesti- knocked over or broken off, they cannot transport food cides. to the bulb. Breaking over the tops also increases neck rot and storage problems. Better ways to hasten bulb Onion Stresses Wind, Pests maturity are to reduce irrigation and fertilizer and/or - undercut the roots with a shovel late in the season. and Diseases On dry, sunny, breezy days, onions may be pulled Wind and left in the garden for a day or two to drybefore they are taken to a curing area. It is best to put the onions on to injury. Often they screens off the ground so that dew and moisture from Onions are very sensitive wind the soil will not affect the bulbs. Bulbs should be are the only plants up in the garden in March and early protected from sunscald by covering with the tops, April and are exposed to the full force of our spring tender. Sand newspaper, or an old bed sheet. Separate out any bulbs winds. Onion leaves are narrow and very can abrade the leaves, creating with thick necks and use them first as they will not store and even silt particles plant. well. Also separate out anybruised or damaged onions openings for disease organisms to infect the the onions from direct and don't try to store these as they are likely to become Using a windbreak protects the protected diseased. mechanical injury and allows the soil in Do not peel or remove the outer skins of onions area to warm quicker resulting in more rapid growth. annual rye grass along the until you are ready to use them. The skins help prevent Planting a narrow row of time moisture loss, bruising and help keep out insect and north and southborders of the garden at the same some Wood disease organisms. you plant onions will provide protection. or plastic snow fencirg also can be used to decrease the Onion Maggots, larvae of the onion fly, tend to be force of the wind on the young plants. Some gardeners a problem on soils high in organic matter during cool, will use a row of straw bales for early protection and wet springs. The fly overwinters as a pupa in onion then disperse the straw as a mulch in late June. Gaps in debris or cull onions left in the garden. The fly emerges the row can funnel the winds resulting in even more in late May or early June and lays eggs in soil at the base wind injury than if no bales were placed for wind of onion plants. The fly is attracted by the odor of protection so be sure whatever you use is a continuous, onions, and plants more than 12 weeks old are rarely although not necessarily solid, barrier. It is actually infected unless the plant or bulb has been injured. There better if the windbreak can act as a fine sieve for the air is no difference in susceptibility to onion maggot be- since this creates a longer protected zone downwind tween transplants, sets, or seeded onions. The fly also from the barrier. Wind injury to onion leaves often tends to prefer to lay eggs where onion plants are looks similar to injury caused by thrips. closely spaced. A second generation of the fly emerges in earlyJuly. There maybe as many as three generations Insects each year in the midwest. Rotating the location of onion plantings is essential to control onion maggot. It also is Thrips occur in all areas where onions are grown. very important to avoid physically injuring onion plants There are two species, the onion thrip and the westem during cultivation or harvesting so that the flies are not flower thrip, that commonly attack onions, garlic, and attracted to the plants. Be sure to remove any damaged related plants. Both species also feed on a wide variety onions from the area. If you find onions infested with of other , flowers, weeds and grasses. In maggot, do not compost these plants! Put them in a Nebraska, thrips are a problem from mid-June on, covered trash container to remove them from your especially in rural areas when wheat is drying. yard. Fewer problems are seen in onions grown on Thrips are hard to see because adults are very small sandy loam soils or on raised bed where there is good (7 / 25 nch long) and they usually feed deep in the neck drainage. Don't mulch too heavily as that also makes of the onion leaves where they are protected from the onions attractive to the flies laying eggs. Onion fly natural enemies and pesticide sprays. attacks only plants in the Alliaceae (onions, , Thrips puncture fhe outer liyei of the leaves with garlic, chives, shallots) and there is no known genetic their rasp-like mouthparts and feed on sap and bits of resistance. leaf tissue. Damage is seen on the leaves after they've elongated. Leaves develop silvery blotches, streaks or Diseases scratch-like markings. Light infestations tend to delay plant growth and retard maturity. Heavy infestations Onion smut is a common disease in temperate cause the leaves tobecome curled, crinkled and twisted, growing regions, especially where onions are grown growth stops, and plants may die. Injury to the plant is from seed. Most onions and related crops are suscep- more severe under hot, dry conditions. They produce tible to smut which attacks only juvenile plant tissue. several generations each summer. Hot, dry weather is Lesions appear as dark streaks seen first on the cotyle- favorable for increased activity and injury. Thrips are dons soon after emergence. On older plants, the streaks hard to control since they hide and feed between the initially appear as long blisters on the leaf surface. As compressed leaves. the lesions mature, they tum brown to black and con- Good cultural practices can limit onion thrips popu- tain a black, powdery mass of spores that give the tops lations. Destruction of volunteer plants and crop resi- a sooty appearance. Diseased leaves may curve down- due after harvest eliminates many favorable ward and usually are shed prematurely. Smut-infected overwintering sites. \zVhen injury is first noticed, apply plants normally are stunted and produce bulbs highly two sprays of insecticide seven days apart. Because prone to soft rot. onion leaves have a waxy surface, it is important to add The onion smut fungus survives in soil as resting a surfactant to the insecticide if it does not already spores that may remain dormant for several years. contain one. Spray with malathion or diazinon, cover- Infection occurs in spring when spores infect young ing the leaves and down into the neck where the insects germinating seeds before the seedlings reach the first hide. leaf stage. The fungus grows with the plant and causes the streaks to appear as true leaves Yellow-Striped Army Worm, a relative of the cut- develop and mature. Infection is occur worm/ appears in late May and early june. It chews on not likely to at soil temperatures greater the outer surfaces of the foliage and then bores into than 80"F. Because smut is disease juvenile leaves and hides inside. Their chewingcauses the leaves a that attacks tissue, seed applied fungicides provide to fall over prematurely. Birds inflict more damage on excellent con- trol. Onion sets and the onions because they like to eat the caterpillars. you transplants are not affected unless attacked in the field as seedlings. Therefore, can minimize infestations of yellow-striped army worms purchase onion sets by keeping the area free of weedy host plants. and plants from a reliable source to avoid purchasing pre-infected plants or sets. Bacterial Soft Rot occurs mainly on maturebulbs in nutrient deficiencies or drought (leaf tips being white, storage. This disease also can develop on onions in the yellow, or brown). Early season infection can result in garden with continued irrigation or rain when the early bulbing and plants with pink root are easily leaves are drying. Thebacteriumenters thebulb through pulled, as with Basal Rot. wounds as a result of mechanical injury, insect injury, Basal Rot and Pink Root can be managed by grow- or sunscald. Affected scales appear water-soaked and ing more tolerant cultivars in gardens with a history of may be light brown or gray. As the rot progresses, these disease problems. Resistant cultivars are avail- scales become soft and sticky and the bulb interior able for Pink Root. These are both soil-borne fungi that breaks down. This rot usually has a foul smell associ- can be present for many years in the garden. Dipping ated with it and liquid can be squeezed from the neck seedlings into a fungicide treatment at transplanting of infected bulbs. can reduce basal rot. Early planting can reduce both To control bacterial soft rot, avoid damaging diseases, as the pathogens are not as active at soil the bulbs during harvest and cultivation and properly temperatures below 75"F. dry bulbs before storage. Avoid overhead irrigation when possible, especially when leaves are drying. Other Cultural Problems Sour Skin and Slippery Skin are bacterial dis- are caused by dry soil during eases. Symptoms appear as one to two leaves that turn Split or double bulbs bulb formation. Irrigate regularly to provide 1 inch of light brown in color, with a watery rot developing at the base of the discolored leaves that proceeds into the water per week as needed to supplement normal rain- when the tops begin to neck. These will be in the center of the leaf cluster if fall. Stop irrigating turn yellow caused by the sour skin pathogen. Scales become in- and fall over. Some cultivars tend to have more double centers than others when grown under the same condi- fected as the disease progresses. The outermost or inner more doubles (center) bulb scales usually are not affected with sour tions and large bulbs are likely to form read descrip- skin. This is a differentiating characteristic from slip- than smaller bulbs. Carefully the cultivar single-centered bulbs are pery skin for which the inner most scales are infected tions in seed catalogues if first. important for you. maybe causedby too late To control these two bacterial diseases, avoid dam- Very smallbulbs planting soil, too close together, aging the bulbs during harvest and properly dry bulbs for the cultivar, dry planting before storage. Cut tops are an excellent point of entry and/or weed competition. for these bacteria. Avoid overhead irrigation as bulbs approach maturity. Onions and Health Purple Blotch mainly infects the leaves. Older Onions have been used in folk medicine for thou- leaves are more susceptible than younger leaves. Leaf sands of years to treat many different ailments. Today, lesions usually have white centers and the edges of the scientists continue to research the role of onions in lesions are brown to purple with yellow tissue around human health. Studies show that regular consumption the lesion. As the lesions mature, dark rings of fungal of onions can help prevent heart disease by lowering spores form throughout the lesions. Severe leaf infec- cholesterol, lowering blood pressure and helping to tion can result in the bulb being infected. Initial bulb thin the bloodl. You can find more information on infection appears bright yellow, but turns a character- scientific studies at libraries, through your physician, istic dark red as symptoms progress. pharmacist, or health-care provider, and by searching Prolonged leaf wetness can lead to Purple Blotch. on the World Wide Web. Avoid overhead irrigation and crowding plants if this Onions contain alliin which is broken down by disease has been a problem in your garden. If overhead alliinase into allicine, and other sulfur-containing com- irrigation is necessary, apply it in the moming. Under pounds. Ajoene is a breakdown component of high disease pressure and wet conditions, a broad and helps to prevent clumping of platelets2. spectrum protective fungicide can be used. Quercetin is a bioflavonoid found in onions, especially the outer Basal Rot is apparent by symptoms of yellowing, rings of red and yellow onions. As an antioxidant, curling and necrotic leaf tips. As symptoms progress/ quercetin inhibits the production of free radicals (oxi- entire leaf blades wither and decay. Infected roots are dants). In the cardiovascular system, it is believed to dark and sometimes hollow. White fungal growth (myce- prevent free radicals from oxidizing low-density lipo- lium) may be present at the base of the bulb and infected proteins (LDL) or "bad" cholesterol3. plants pull easily due to a stunted, decayed root system. 1Duke, Pink Root is similar to Basal Rot. The name "pink James A.1999.Dr. Duke's Essential Herbs. St. Martin's Press. ISBN 1-57954-183-6 root" describes the most obvious symptom of this ,Ibid disease. Roots become deeper pink to red as symptoms 3lau, Benjamin. 1999. Garlic and You; the Modern Medicine. Apple progress. Severely infected plants appear to suffer from Pub Co Ltd; ISBN: 1895817025 This brief overview of onions in human health is sterile. Propagation is primarily by using the bulbils, meant to increase your knowledge of research in the which are planted in the fall. role of plants in human health. Because everyone is different, a physician must diagnose conditions and Multiplier Onion or supervise the use of diet, herbs, or supplements to treat individual health problems. You should talk with your The potato or multiplier onion (Allium cepa var. doctor before adding supplements or large amounts of solanium) also is grown from vegetative parts rather onions or onion extracts to your diet. Since onions and than true seed. The underground portion is a com- garlic can reduce blood clotting time, one should be pound bulb formed from the segregation of a large especially careful if one already takes prescription anti- motherbulb. Eachbulb in the compound bulb produces coagulants. six to 12 plants. The bulbs are about the size of a , Pet owners should be aware that, while many flattened on one end. The multiplebulbs are enclosed in animals like the flavor of cooked garlic and onions, they the sheath of the mother bulb until they are well devel- can make cats, dogs, horses, sheep, cattle and other oped. Commercially, their principal use is to produce animals very ill. Compounds in onions and garlic de- early greenbunching onions. Lr the home garden, they stroy the red blood cells of many animal species causing can supply a never ending source of onions if allowed hemolytic anemia. Prolonged or exclusive feeding of to grow continually. onions may cause death of the animal. Multiplier onions are planted in the fa1l, overwin- tered with some mulch protection, and brought into Other Onions production in the early spring. Due to this method of culture, the onions are referred to as "winter onions." Seedlings can be eaten in the fall, but are commonly Green Bunching Onions () left until the following spring. If picked before flower- Any standard onion cultivar can be used for pro- ing, these onions make an excellent green onion for use ducing green onions. For the home gardener, green in soups and salads. The mother plant can be con- onions are usually the by-product of thinning over- sumed; however, the seedlings are much preferred. crowded rows. Onions can be used as green onions The mother plant can be left to provide a continuous starting about 30 days after planting if grown from source of new seedlings. Like chives, perennial onion plants or sets. The cultivars 'southport \A/hite Globe' plants produce offshoots. Therefore, the patch should and 'White Sweet Spanish' are often grown for green be renewed by division every four or five years to onions rather than bulbs. control and rejuvenate its growth. True green bunching onions are cultivars of. A. Pearl Onions. True pearl onions are classified as fistulosum that do not formbulbs. 'Ishikura', 'Evergreen Allium ampeloprasurn (Ampeloprasum group) and are \ /hite Bunching' or 'Welsh Onion' ('He Shi Ko') are distinctly different from regular onions because they examples. They are winter hardy but are usually grown form just one storage leaf and so true pearl onions do as an annual crop. In Japan and China, transplants are not have rings. Commercially, pearl-size onions often planted in a furrow and soil is mounded around the are produced in the north by planting short-day culti- plants to blanch the elongated pseudostem or basal vars of common onions such as 'Grano' and 'Crystal part. If not blanched, they are grown for the green tops. Wax.' Although we are accustomed to scallions or green onions with a white base, cultivars are available that Shallots (Allium cepa var. ascalonicum) are hardy members have an attractive purple or reddish base. The cultivar of the onion family and have a mild flavor 'Bunching', is the result of a chance cross between prized by gourmet cooks. They are often called for in French cooking and be A. fistulosum and A. cepa and will form small bulbs may used in the green onion or swollen leaf bases. stage or as bulbs. Originating from the beginning of Christianity, they are likely only a modification of a cultivar of onion. Shallots are cultivated Egyptian-, Walking-, Top- or Tree-onions like onions, though they may be planted in the fall or early spring Those plants known as Egyptian-, walking-, top- and mature earlier in the summer. There are a few listed or tree-onions are in another group withnAllium cepa. cultivars of varying pungency and ability to overwin- They produce clusters of smallbulbs (bulbils) at the top ter, but often they are simply listed as "shallots." Plant- of the seed stalk in late summer and are exceptionally ing stock may be purchased from garden stores, seed winter-hardy. The bulbils often sprout while still on the companies or the produce section of some grocery seed stalk and when the stalk falls over, they begin to stores. grow. Hence, they "walk" across the garden and may Shallots produce a cluster of bulbs from a single spread into a large patch. The bulbils also may be planted bulb. To plant, divide the clump of shallots into harvested and used as tiny onions, for example, in individual bulbs and separate them by size. Plant the salads. Although these may form flowers, they are often small bulbs and use the large bulbs for cooking. Plant early in the spring, as soon as the soil can be worked. Chives are easily started from seeds, or clumps Like other onions, shallots thrive in rich, loose soil. may be divided and transplanted in the spring. A few Plant the individual bulbs 1 to 1,1. /2 inches deep and 4 plants or small patch will be sufficient for the average to 5 inches apart, or if in wide rows, space the bulbs 5 family. They do not spread rapidly and seldom become inches apart in all directions. Shallot bulbs develop on a weed. As chives multiply by offshoots, a patch will top of the ground. Do not cover with soil when cultivat- begin to crowd itself out as it spreads. The plants may ing. lose vigor and die. Rejuvenate a crowded patch by Shallots also can be planted in mid- to late-October. dividing the plants, thinning them andlor transplant- Plant the bulbs 2 to 3 inches deep and mulch lightly. ing them to another area of the garden. Shallots are very hardy and will survive most winters Small amounts of chives may be snipped off for without a heavy mulch. fresh use throughout the growing season. If you plan to Shallots may be pulled as green onions when their fueeze or process the chives, remove a1l growth about2 tops are 6 to 8 incheshigh. Eachbulb ("scallion")willbe inches above the ground. This should be done only once 3/8 inch or larger in diameter. For dry bulbs, allow the ayear, before mid-]uly, to al1ow the bulbs to replenish tops of the plants to die down in July. Harvest and their food reserves before winter. Where winters are handle in the same manner as dry onions. The dry bulbs severe with little snow cover, a 2 inch layer of mulch can may be placed in a mesh bag and stored under cool, dry be placed over the patch in late fall to help prevent conditions. Shallots keep well and are easily stored winter injury. until planting time in the fall or spring. Garlic Chives or Chinese Chives (Alll um tuber o sum) are similar to chives except their leaves are flat and they Chives have a mild garlic flavor. Plants grow in clumps that spread by tillering. The leaves are harvested when they are about 8 inches long. The flower stalks and flowers Chives (Allium schoenoprasum) are a mild-flavored are also eaten, ideally when about 14 inches tall and the member of the onion family often considered more of buds are still green and closed. These are used in stir-fry an herb than a vegetable. They have been grown as a dishes or soups to add a mild garlic flavor. The bulbs of crop in Europe since the 16th century. The fine-textured garlic chives are very small and of no consequence. The foliage is chopped and used in soups, stews, salads, and flowers are fertile and scatter seeds, so they often other recipes. The bulb is small and not usually con- become weeds. The culture is the same as for chives but, sumed. Chives also are used as an edible omamental to reduce the problem of self-seeding, prune off the flower, bearing lavender blossoms spring to early in flowers before they produce seed. summer which can be used to gamish salads and other dishes.