Circular 935
Robert R. Westerfield, Extension Horticulturist
If vegetables are not harvested at the proper stage of maturity, physiological processes occur that permanently change their taste, appearance and quality. The texture, fiber and consistency of all vegetables are greatly affected by the stage of maturity at harvest, by post-harvest handling and by the time interval between harvesting and serving.
Some vegetables are more highly-perishable than others. Sweet corn and English peas are difficult to maintain in an acceptable fresh state for even a very short time, while other vegetables have a much longer shelf life.
Harvesting most vegetables when they are young and storing them properly will help extend their shelf life. In some cases, newer hybrid varieties have helped add shelf life to certain vegetables. Lowering the internal temperature also helps to slow both the respiration process and quality decline. This is one reason for harvesting vegetables early in the day before the heat from the sun has warmed them. After the harvest, most vegetables should be kept cool and out of direct sunlight until they are either processed or consumed.
While harvesting too soon may result in only a reduction in yield, harvesting too late can result in poor quality due to development of objectionable fiber and the conversion of sugars into starches. A late harvest can also cause plants to terminate, or stop producing as they complete their reproduction process. Fully-mature vegetables left on the plant also attract more disease and insect problems. The following table gives suggestions for determining the proper stage of maturity for harvesting many vegetables.
| Vegetable | Part Eaten | Too Early | Optimum Maturity | Too Late |
|---|---|---|---|---|
| Artichoke, Globe | Immature bloom | Small flower buds | When buds are 2" to 4" in diameter | Large buds with loose scales or bracts |
| Asparagus | Stem | Insufficient length | 6" to 8" long; no fiber | Excess woody fiber in the stem |
| Beans, Lima | Seed | Insufficient bean size | Bright green puffy pod; large seed | Yellow pods |
| Beans, Pole Green | Pod and seed | Insufficient size | Bean cavity full; seed ¼ grown | Large seed; fibrous pods |
| Beans, Snap Bush | Pod and seed | Insufficient size | Turgid pods; seeds just visible | Fibrous pods; large seed |
| Beets | Root and leaves | Insufficient size | Roots 2" to 3" in diameter | Pithy roots; strong taste |
| Broccoli | Immature bloom | Insufficient size | Bright green color; bloom still tightly closed | Loose head; some blooms beginning to show |
| Brussels Sprouts | Head | Insufficient size; hard to harvest | Bright green; tight head | Loose head; color changes to green-yellow |
| Cabbage | Head | Insufficient leaf cover | Heads firm; leaf tight | Loose leaf; heads cracked open |
| Cantaloupes | Fruit | Stem does not want to separate from fruit | Stem breaks away easily and cleanly when pulled | Yellow background color; soft rind |
| Carrots | Root | Insufficient size | ½" to ¾" at shoulder | Strong taste; oversweet |
| Cauliflower | Immature bloom | Head not developed | Compact head; fairly smooth | Curds open; separate |
| Celery | Stems | Stem too small | Plant stands 12" to 15" tall; medium-thick stem | Seed stalk formed; bitterness |
| Collards | Leaf | Insufficient leaf size | Bright green color; small midrib | Large midrib; fibrous |
| Corn, Sweet | Grain | Grain watery; small | Grain plump; liquid in milk stage | Grain starting to dent; liquid in dough stage |
| Cucumber | Fruit | Insufficient size | Dark green skin; soft seeds | Skin beginning to yellow; hard seeds |
| Eggplant | Fruit | Insufficient size | High glossy skin; side springs back when mashed | Brown seeds; side will not spring back when mashed |
| Lettuce, Head | Leaves | Head not fully formed | Fairly firm; good size | Heads very hard |
| Okra | Pod | Insufficient size | 2" to 3" long; still tender | Fiber development; tough pods |
| Onions, Dry | Bulb | Tops all green | Tops yellow; ¾ fallen over | All tops down; bulb rot started |
| Peas, English | Seed | Peas immature and too small to shell | Peas small to medium; sweet bright green | Yellow pods; large peas |
| Peas, Southern (green) | Seed and pod | Peas immature and too small to shell | Seeds fully developed but still soft; soft pods | Hard seeds; dry pods |
| Pepper, Pimiento | Pod | Insufficient size | Bright red and firm | Shriveled pod |
| Pepper, Red Bell | Pod | Chocolate-colored pods | Bright red and firm | Shriveled pod |
| Potato, Irish | Tuber | Insufficient size | When tops begin to die back | Damaged by freezing weather |
| Potato, Sweet | Root | Small size; immature | Most roots 2" to 3" in diameter | Early plantings get too large and crack; damaged by soil temperature below 50°F |
| Rhubarb | Stem | Small size; immature | Stem 8" to 15" long is best | Fleshy stem becomes fibrous |
| Soybeans | Seed | Seeds not developed | Thick pods; bright green | Dry pods; seed shatters out |
| Squash, Summer | Fruit | Insufficient size | Rind can be penetrated with thumbnail | Penetrating with thumbnail is difficult; large seed |
| Squash, Winter | Fruit | Soft rind | Rind difficult to penetrate with thumbnail | Damaged by frost |
| Tomatoes | Fruit | May be harvested in three stages: Mature green – tomato is firm and mature, color changes from green to light green, no pink color showing on blossom end. These tomatoes will store one to two weeks in the refrigerator. Pink – pink color about the size of a dime on the blossom end. At room temperature, these tomatoes will ripen in about three days. Ripe – tomato is full red but still firm. Should be used immediately. | ||
| Watermelon | Fruit | Green flesh; green stem is difficult to separate | Melon surface next to the ground turns from a light straw color to a richer yellow | Top surface has a dull look |
Acknowledgement is made to Willie O. Chance III and Darbie Granberry for authoring the original manuscript of this publication.
Status and Revision History
Published on May 01, 1999
Published with Full Review on Nov 08, 2011
Published with Full Review on Nov 30, 2014
Published with Full Review on Aug 18, 2022
In the realm of horticulture and agriculture, understanding the nuances of vegetable harvesting and post-harvest handling is crucial. The article you mentioned touches upon the critical factors influencing vegetable quality: stage of maturity at harvest, post-harvest handling, and the subsequent impact on taste, appearance, and longevity.
When it comes to ensuring vegetables maintain their optimal quality, several key concepts come into play:
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Maturity Stage: Harvesting vegetables at the right stage of maturity is paramount. For instance, beans harvested too early might lack flavor or texture, while harvesting them too late could result in fibrous pods and oversized seeds.
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Post-Harvest Handling: Proper handling post-harvest significantly affects shelf life. Cooling vegetables and protecting them from direct sunlight are essential measures to slow down degradation processes.
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Shelf Life Extension: Newer hybrid varieties often contribute to extending shelf life. Additionally, maintaining a lower internal temperature after harvest can slow down the degradation of quality.
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Determining Maturity: The article provides a comprehensive table detailing the ideal maturity stages for various vegetables. For example, it mentions the right size, color, texture, or specific conditions indicating the optimal harvest time for each vegetable, from asparagus and beans to tomatoes and watermelon.
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Impact of Late Harvest: Harvesting too late can lead to negative consequences such as increased disease susceptibility, texture changes, and reduced overall quality. This not only affects taste but also influences the plant's life cycle and susceptibility to pests.
Understanding these principles helps farmers and gardeners maximize the quality and yield of their vegetable produce. By adhering to proper harvesting practices and post-harvest care, they can ensure vegetables reach consumers in their best possible condition.
The mentioned article by Robert R. Westerfield acts as a comprehensive guide for growers, providing detailed insights into determining the right maturity stage for harvesting various vegetables and the subsequent implications on their quality and taste.
