When to Plant Onions Where You Live!

An article by Travis Key from Lazy Dog Farm

Onions are a staple in many backyard gardens, but choosing the right type for your region is key to growing a successful crop. Onions fall into three categories based on how much daylight they need to form bulbs: short-day, intermediate-day (also known as day-neutral), and long-day onions.

Each type thrives in different parts of the country due to variations in day length and climate. Understanding these differences will help you determine the right variety to plant and the best time to plant it.

Short-Day Onions

Short-day onions begin forming bulbs when daylight reaches 10-12 hours. These varieties are well-suited to southern regions, where winters are mild, and days are shorter. They require less daylight than other onions to trigger bulb formation, which means they begin bulbing earlier in the season.

Short-day onions grow best in areas like the southern U.S., including states like Texas, Louisiana, Georgia, and Florida. These regions experience milder winters and shorter days, ideal for short-day onions to begin bulbing before the summer heat arrives.

In southern regions, short-day onions are typically planted in the fall (October to December) for a spring harvest. Planting in the fall gives onions time to establish roots and foliage before bulbing begins as the days start to lengthen in the spring. In warmer climates, onions can also be planted in late winter.

Intermediate-Day Onions

Intermediate-day onions, also called day-neutral onions, form bulbs when daylight reaches 12-14 hours. These onions are more adaptable than short-day and long-day varieties and can be grown in a wider range of climates. They are ideal for regions with moderate winters and springtime daylight of moderate length.

Intermediate-day onions thrive in central parts of the U.S., such as the Mid-Atlantic, southern Midwest, and parts of California. States like Tennessee, Kentucky, and Virginia offer ideal growing conditions for these onions.

In regions suitable for intermediate-day onions, planting typically occurs in late winter to early spring (January to March). Gardeners should aim to plant these onions when the risk of severe frost has passed, but before temperatures climb too high, which could stress the plants before they have a chance to bulb.

Long-Day Onions

Long-day onions require 14-16 hours of daylight to form bulbs, making them ideal for northern regions with long summer days. These onions grow best in areas where the summer days are lengthy, allowing them the extended daylight hours they need to produce large bulbs.

Long-day onions are best suited for northern areas of the U.S., including states like Washington, Oregon, Michigan, and New York. These regions have cooler summers and experience longer daylight hours, which are perfect for long-day onions to reach their full potential.

In northern regions, long-day onions should be planted in early spring (March to April). Gardeners should wait until the soil is workable and has warmed up, but it’s important to plant before the long summer days arrive to ensure the plants have enough time to develop before bulbing begins.

Planting Onions Across the U.S.

To help you figure out when to plant onions in your region, here are some general guidelines based on your location and the type of onion you are planting:

1. Southern U.S. (Zone 7 and warmer):

• Best onion type: Short-day onions
• Planting time: October to December (fall planting) or January to February (late winter)
• Example locations: Texas, Louisiana, Mississippi, Alabama, Florida, and Georgia

2. Central U.S. (Zones 6-7):

• Best onion type: Intermediate-day onions
• Planting time: January to March (late winter to early spring)
• Example locations: Tennessee, Kentucky, Oklahoma, Virginia

3. Northern U.S. (Zones 5 and colder):

• Best onion type: Long-day onions
• Planting time: March to April (early spring)
• Example locations: New York, Michigan, Oregon, Washington

By understanding the daylight needs of onions and choosing the right variety for your region, you can enjoy a bountiful onion harvest. Whether you're in the sunny South or the cooler North, selecting the right type and planting at the appropriate time is the key to success.

Thousands of gardeners have been tuning in to The Lazy Dog Farm YouTube channel where Travis covers a variety topics ranging from how to successfully start seedlings to how to make a flavorful hot sauce that packs a punch. Accompanied by his wife Brooklyn and their two boys, the gardens on their 2 acre homestead in southwest Georgia are always filled with a wide variety of vegetables that are enjoyed fresh or preserved for later.