The Strawberry: Its History, Description, and Care
The History of the Modern Strawberry
It is believed that strawberries have grown in temperate climates all around the world since ancient times. The wild strawberry was known to the ancient Greeks and Romans. Two of the earliest records of the strawberry are found in writings of Roman poets, Ovid and Virgil. The strawberry was included in a first century encyclopedia of nature written by a Roman scholar named Pliny. During the first centuries, the wild strawberry was utilized not only for food, but also as an ornamental flower and as medicine. The leaf, root, and berry were used to alleviate symptoms of depression, bad breath, fever, throat infections, and diseases of blood, liver, and spleen. It is also know that the strawberry was being cultivated by the peoples of the Americas prior to the arrival of the early European explorers and colonists. There are records also of a strawberry plant that produced yellow flowers native to India.
The development of the modern strawberry has an intriguing history that blossomed with the exploration and colonization of the New World. In the 1300's the French began to cultivate the wood strawberry (Fragaria vesca) mainly for ornamental use. Near the end of the 1500's three European species had been identified: the wood strawberry (F. vesca), the musky strawberry (F. moschata), and the green strawberry (F. virdis). The two strawberries cultivated in gardens were the wood (F. vesca) and musky strawberry (moschata), both were described as being small, and good-tasting. Sometime during the early 1600's a new species was introduced to Europe from eastern North America, the Virginia (F. virginiana). This was to be the father of today's large modern strawberry. It was a larger berry than European varieties, but lacked flavor. No one is sure as to how this plant was brought to Europe, but is thought that it first arrived in England or France and then gradually moved throughout Europe. Another significant event influencing the cultivation of the modern strawberry was in 1714. Louis XIV sent a group to spy on the Spanish fortifications in South America. An engineer, Amédée Francios Frézier, took extensive notes regarding Spanish strengths and weakness, operations of the church, customs of Indians, agricultural products, and drew maps to show best approaches for attack. He described in detail the exceptionally large-fruited strawberry which grew on the coast near Concepción. He took several strawberry plants back to France as gifts for the king and for himself. This fruit was the mother of the modern strawberry, the Chilean Strawberry (F. chiloensis).
The discovery of the modern strawberry's heritage was due to the work of French and English botanist. The French botanist, Antoine Nicholas Duchesne (1747-1827) is recognized for his research in the genus of strawberries, his conclusions remain generally valid today. He began his work at the age of seventeen when he used the pollen of the musky strawberry (F. moschata) with the Chilean berry (F. chiloensis); the result was a fruiting F. chiloensis. This was a very rare specimen, since there were no males of the F. chiloensis variety in Europe. A pot of these strawberries were presented to King Loius XV, who honored Duchesne's achievement by allowing him to use the royal kitchen garden at Versailles to study and collect all varieties of strawberries known in Europe. He preformed a detailed study of the plant family, Fragaria. His book described their genus and an examination of ten species and eight varieties that he classified. He also traced the history, cultivation, and distribution in Europe. He was the first to recognize the separation of sexes in some varieties of strawberries such as the F. chiloensis.
During the late 1700's and 1800's the English involvement in the breeding of strawberries led to the development of many new varieties. One man who largely influenced this movement was Thomas Andrew Knight (late 1700's-1838). He is credited for developing basic breeding techniques used today. He made the first scientific attempt at strawberry breeding on a large scale; two of his most well known varieties are the Downton strawberry and the Elton. Another Englishmen who influenced the progress of the modern strawberry was grower named Michael Keens. He was the first to raise and market a large-fruit strawberry he had developed known as the Keen Seedling. This variety is used in practically all varieties today. Many growers were motivated by the success of these two men to develop more varieties in search of the perfect strawberry. Today there are more than one hundred varieties.
The Characteristics of the Strawberry and Its Care
The strawberry plant, a low perennial herb, is a native to temperate climates around the world. The strawberry is unique in that it is the only fruit with seeds on the outside of the fruit rather than the inside. The plant consists of a crown and stems from which the roots grow downward. Half of the root system is in the upper six inches of the soil. The upper portion of the plant is 6 - 8 inches tall, spreading about 1 foot in diameter. The leaves are light green, rounded with jagged edges; the flower is formed by five white petals that will develop into red fruit after pollination. Development of the fruit from pollination to ripeness takes 20 to 60 days, depending on the cultivar and weather conditions.
Strawberries are generally classified as day neutral, everbearing, or June-bearing. June-bearing varieties will produce one crop per year, in late spring or early summer. Everbearing and day neutral varieties flower and set fruit throughout the year as long as the weather is appropriate. Day neutral berries are a new variety of everbearing strawberries that bears evenly throughout the season. The harvest of the older everbearing variety will peak in early summer, continue to produce fruit through fall, and peak again in fall. The fruiting pattern varies and is dependent on variety and weather conditions. Strawberry plants will not produce flower buds when nighttime temperatures remain above 60ˇF (16ˇC). If daylight is shorter than 14 hours and temperatures are below 45ˇF (13ˇC), the plant will be in dormant state.
Optimal conditions for growing strawberries is in full sun in soil with a water pH of 7.0. The soil should be kept evenly moist and well drained. In warm-winter climates which have an average January temperature of 50ˇF (10ˇC), plant in fall. Fall/winter planting has several advantages in that the plants will provide early fruit, have a more even fruit production, higher yields, and are less costly than summer plantings. In cold-winter climates, plant in spring. The advantages of spring/summer plantings are that they are more tolerant of soil salinity and tend to have less leaf spot diseases than winter plantings.
The best time to plant is dependent on variety and weather. Choosing the correct date for planting helps to improve yields and reduce pest problems. Generally, strawberries are transplanted rather than seeded. It is important to protect transplants from drying out during the planting process. Place them into raised beds with soil moisture to near capacity. Plant in rows with 4-6 inch irrigation furrows in between rows. Proper placement of plant into soil is critical. Be sure that the top of the crown is level or slightly above the soil surface. The holes should be deep enough for the roots to extend downward. Recommended spacing for winter plantings, is 10-12 inches between rows and 12-16 inches between plant in the rows and for summer plantings it is 12-14 inches between rows and between plants in the row.
Strawberries like to grow in well-drained, evenly moist soil. Irrigate summer plantings frequently to keep the field bed to near capacity. Avoid standing water in furrows since excessive water amounts lead to disease. Summer plantings will need constant irrigation for 6-8weeks. For winter plantings, place mulch on plants as soon as possible and continue to irrigate enough to keeps soil moist until rainy weather starts or the danger of frost is past.
Most strawberry varieties reproduce by sending out runners that develop into daughter plants. If large plants with small yields of big berries are desired, then pinch off runners during the first 3 months after planting. If the desire is to have heavy yields with smaller berries, then allow runners to grow into offset plants about 7-10 inches apart. When the plants have made enough offsets, pinch off the runners.
Harvest fruit when it is fully colored. Once the berry is picked it does not continue to ripen. Dispose any over ripe fruit or fruit with signs of decay, since decay spreads quickly throughout the collected berries. The following procedures will help to prevent decay and prolong shelf life during harvest:
- Provide shade for fruit held in the field
- Protect fruit from warm winds
- Remove fruit from the field within 1 to no more than 2 hours following harvest.
- Cool fruit to 32ˇ-34ˇF (0ˇ-1ˇC) as quickly as possible and prevent warming during storage, loading, and transit.
Diseases that effect strawberries are botrytis (fruit rot), red stele (root rot), yellows (virus), or verticillium wilt (fungus) To reduce the risk of strawberries acquiring diseases replant every 1-2 years. To avoid mold problems, cut out damaged fruit and use mulch to keep fruit off the ground. Mulch also helps to reduce weed growth. Spider mites and aphids are usually controlled by spray of insecticidal soap or garlic spray.
Cover cropping enhances pest control and helps to improve soil structure. Rotate strawberries with crops such as rye, barley, or bell beans. Broadleaf herbicides cause serious problems with strawberries, so a cover crop of rye or barley that compete with weeds will be an effective weed control. Incorporation of cover crop residues loosens the soil and can help with soil drainage. Be sure to allow enough time for cover crop to decompose before preparing the field for planting.
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