Pearl onions
![pearl onions pearl onions](https://i5.walmartimages.com/asr/d63ced73-8354-413d-a42f-9cd14c860fe1_1.88683fe5be51e5af6f7210363eb61e46.jpeg)
Time of bulbing is an important factor in determining onion bulb size.
![pearl onions pearl onions](http://www.amodestfeast.com/wp-content/uploads/2016/11/Pearl-Onions-With-Pancetta.jpg)
Overcast skies and cool temperatures delay bulbing. High temperatures and bright days can "compensate" for some day length, causing onions to bulb sooner than they would otherwise. Temperatures and light intensity and light quality (red:far red) can modify onion bulbing response. These are grown in southern states, generally below the 35th parallel, and are not suitable for bulb production in the northwest, except as pearl or boiler varieties, or for overwinter production. Short-day varieties are those requiring only 10 to 12 hours of day length for bulbing to occur. Technically, all onions are "long-day" plants, in that bulbing begins as day length increases. Onions for "sets" or "boiler" production may be short, intermediate, or long-day types also grown at high populations and using planting dates that capitalize on optimum warm summer temperatures at bulbing. Pearl onions are short-day varieties grown under the Northwest's long-day summer conditions and planted at very high plant populations to produce the necessary yields. Small bulb onions are usually produced in the Northwest by using techniques that capitalize on the onion's response to day length, plant density, and temperature. Variety, plant density, photoperiod, and temperature are several important ones. Onion bulb size is influenced by a number of factors. For more information on onion culture, refer to the files Dry Bulb Onions - Eastern OregonĀ and Dry Bulb Onions - Western Oregon.
![pearl onions pearl onions](https://www.5starpeeled.com/wp-content/uploads/2019/11/Unpeeled_Red_pearl-onion.jpg)
Note: This file contains only information specific to production of pearl, set, and boiler onions.