Virginia Beach sits at 36.82 degrees north, and on the longest day of the year it gets 14 hours and 32 minutes of daylight. That single number decides which onion varieties will actually form a bulb here and which ones will just sit in the ground making leaves. This page sorts out both, plus when to plant and what kind of onion your climate is built to grow.
How long your longest day is
Start with the two numbers that matter more than soil, fertilizer, or watering schedule: 36.82 degrees north, and 14 hours 32 minutes of daylight at the June solstice. That’s the figure measured at the reference station near Virginia Beach (NAS Oceana), and it’s the one an onion plant is actually reading. Onions don’t bulb because the weather warms up. They bulb because the day gets long enough to flip a switch in the plant, shifting it from growing leaves to swelling a bulb underground.
At just over 14 and a half hours, this location clears the roughly 12-hour threshold that triggers short-day varieties, and it also reaches into the range where intermediate-day types start bulbing. It falls short of the 15-to-16-hour ceiling that some long-day northern varieties want before they’ll switch over, though several long-day types have wide enough ranges to still work here. That’s the whole story of this page in one sentence: intermediate-day onions are the safe bet, some long-day varieties will work, and short-day onions bred for the Deep South or Gulf Coast will bulb too early and stay small. For a full breakdown of dates, see When to Plant Onions in Virginia.
Virginia is not one climate. It’s a state that runs from the Atlantic coast to the Blue Ridge and on into the mountains near Tennessee and Kentucky, and that’s several degrees of latitude end to end. A gardener in Virginia Beach and a gardener in Abingdon are not gardening under the same sky, even though both live in “Virginia.” If you’re near the coast, the 36.82N figure above is close to yours. If you’re up near the West Virginia line or tucked into the mountains in the southwest corner of the state, your actual daylight hours will run a little different, and it’s worth checking your own latitude rather than assuming the coastal number applies to your backyard.
Which varieties bulb in Virginia
Twelve documented varieties have a published latitude range that covers 36.82N, which means they’re built to bulb reliably at this day length. That list leans intermediate-day, with a couple of long-day exceptions that happen to have a wide enough range to reach this far south. For a closer look at each of these, see The Best Onion Varieties for Virginia.
- Bridger (long-day, 35-50N)
- Cabernet (intermediate-day, 35-45N)
- Calibra (intermediate-day, 35-45N)
- Candy (intermediate-day, 33-40N)
- Elsye (intermediate-day, 32-45N)
- Expression (intermediate-day, 32-45N)
- Monastrell (intermediate-day, 35-46N)
- Red Long of Tropea (intermediate-day, 35-48N)
- Scout (intermediate-day, 32-46N)
- Sierra Blanca (intermediate-day, 32-45N)
- Walla Walla Sweet (long-day, 35-55N)
- White Castle (short-day, 30-38N)
Now the list that actually matters more, because this is the mistake that costs a whole season. Eleven varieties are published for latitudes that don’t include 36.82N at all, and if you plant one anyway, here’s exactly what happens. Five are short-day types bred for latitudes below this one, meaning the day here gets long enough to trigger bulbing while the plant is still too small to make anything worth harvesting. You end up with a marble-sized onion instead of a fist-sized one. That’s not a fertilizer problem. That’s a variety problem.
- Gabriella (short-day, 20-35N)
- Madalyn (short-day, 20-35N)
- Red Sensation (short-day, 25-35N)
- Texas Grano 1015Y (short-day, 25-35N)
- Vidora (short-day, 25-35N)
The other six run the opposite direction: long-day varieties bred for latitudes above this one. Plant one of these in coastal Virginia and the day never gets long enough here to flip the switch at all. The plant just keeps making leaves all summer, then rots in the ground once the heat and humidity catch up to it. No small onion, no onion at all.
- Frontier (long-day, 40-50N)
- Powell (long-day, 43-47N)
- Red Carpet (long-day, 40-45N)
- Redwing (long-day, 43-65N)
- Safrane (long-day, 42-50N)
- Talon (long-day, 42-50N)
Eight more varieties sit within a degree and a half of their published boundary, close enough to this territory that they might bulb, might not, and are worth trying only if you already have a favorite from this group and want to gamble a few feet of row on it: Ailsa Craig, Barolo, Blush, New York Early, Patterson, Red Long of Florence, Red Rock, and Rossa di Milano. Treat that group as a maybe, not a plan.
When to plant onions in Virginia
Planting time follows day length, which is why it shifts as you move around the state and around the country. At the reference station near Virginia Beach, the 1991-2020 climate normals put the last spring frost between March 20 and April 3, and the first fall frost between November 10 and November 24. Those are averages built from decades of data, not a promise about any single year, so treat them as the range to plan around rather than a date circled on the calendar.
For most of Virginia, intermediate-day onions go in as young transplants or sets in late winter to early spring, timed so the bulk of leaf growth happens before the longest days of June trigger bulbing. Onions tolerate a light frost fine once established, so gardeners here typically get transplants or sets into the ground several weeks ahead of that March 20 to April 3 last-frost window rather than waiting for it to pass. That head start matters because the plant needs a decent root and leaf system built up before day length forces it to switch into bulb-making mode.
The frost-date caution matters more the farther you get from the coast. Coastal Virginia Beach represents the mild end of the state’s climate. The Blue Ridge and southwest Virginia run their last frost weeks later in spring and their first frost weeks earlier in fall, which compresses the whole growing window. A gardener in those regions should push planting later in spring and expect to pull a shorter season overall, using local extension frost data for their specific county rather than the coastal numbers above.
Sweet onions or onions that keep
Here’s the trade-off Virginia gardeners actually face, and it’s chemistry, not luck. Onion bite comes from volatile sulfur compounds, and those same compounds are what protect a bulb in storage. Sweet varieties have fewer of them, which makes them better eaten fresh but poor candidates for a root cellar. University of Missouri Extension states it plainly: as a rule, sweet onions do not store as well as the more pungent types.
This lines up directly with day length. Short-day varieties, the ones bred for the Deep South, tend to run sweeter and store shorter. Long-day varieties, bred for the far north, tend to run sharper and keep longer, sometimes into spring. Virginia’s day length sits in intermediate territory, and so does its onion crop: expect flavor and storage life that split the difference rather than lean hard either way.
Walla Walla Sweet, one of the long-day varieties whose range does reach this latitude, is a case in point. It’s genuinely sweet and genuinely short-keeping, closer in behavior to a southern onion than its long-day label suggests. Most of the intermediate-day varieties on the list above (Candy, Cabernet, Scout, Sierra Blanca, and the rest) fall into a middle ground: milder than a classic storage onion, firmer and longer-lasting than a true sweet.
What that means for the pantry: a Virginia garden won’t produce the kind of onion that lasts, sound and firm, all the way to next year’s harvest the way a hard northern storage onion can. Expect good eating from midsummer through fall, with quality onions fading out sometime over the winter rather than holding cleanly into March. If long storage matters more to you than sweetness, look toward the longer-keeping end of the intermediate-day varieties on the list rather than expecting a true northern storage onion out of this climate.