How to Grow Onions in Kitsap County: Best Varieties, Planting Times, and Tips for a Successful Pacific Northwest Harvest

If you've ever pulled a soft, disappointing onion from the ground after months of waiting, you know how deflating it can be. Growing onions in Kitsap County isn't difficult, but it does require a little local knowledge. The Pacific Northwest has its own rhythm, and onions respond strongly to day length, soil temperature, and seasonal moisture. Get those factors working in your favor and you can harvest beautiful, full-sized bulbs by midsummer.

May is a good time to take stock of where your onion bed stands. Transplants should be in the ground, sets may still be going in, and the soil is finally warming enough to push real growth. Here's what you need to know to make the most of the season ahead.

Why Day Length Matters More Than You Might Think

Onions are triggered to form bulbs by the number of daylight hours, not by temperature or calendar date. This is the detail that trips up many first-time onion growers. There are three categories to know:

• Long-day onions bulb up when days reach 14 to 16 hours of light. These are the right choice for Kitsap County and most of Washington state.
• Short-day onions are bred for southern climates and will bulb too early here, producing small, underdeveloped results.
• Intermediate-day onions can sometimes work in the Pacific Northwest but are less reliable than long-day types.

Kitsap County sits at a latitude where summer days are long enough to trigger excellent bulb development in long-day varieties. Choosing the right type from the start is the single most important decision you'll make.

Best Onion Varieties for the Pacific Northwest

Not all long-day onions perform equally well in our cool, maritime climate. These varieties tend to do well for Kitsap County home gardeners:

• Walla Walla Sweet — A Pacific Northwest classic. Mild, large, and well-suited to our region. Best for fresh eating rather than long storage.
• Yellow Sweet Spanish — A reliable producer with good size and mild flavor. Stores reasonably well.
• Copra — An excellent storage onion. Smaller than Sweet Spanish but keeps for months if cured properly.
• Red Zeppelin — A long-day red onion with good storage potential and bold color.
• Patterson — One of the best storage onions available for the Pacific Northwest. Worth seeking out if long-term storage is a goal.
• Cipollini types — Flat, small, and sweet. Great for roasting. Less common but a nice addition for home chefs and specialty cooks.

If you're also growing garlic this season, it's worth reading our guide on growing garlic in Kitsap County, since both belong to the allium family and share similar soil needs and rotation considerations.

When and How to Plant Onions in Kitsap County

Onions can be started three ways: from seed, from transplants, or from sets (small bulbs). Each has its place depending on your goals and timeline.

From seed:

• Start indoors 10 to 12 weeks before your transplant date, typically January or early February for Kitsap County
• Seeds need consistent warmth to germinate, around 65 to 70 degrees
• Transplant outdoors once seedlings reach pencil thickness, generally late March through April

From transplants:

• The most reliable method for home gardeners
• Plant out in late March through April, or by early May at the latest
• Space transplants 4 to 6 inches apart in rows 12 inches apart
• Plant shallowly, no deeper than an inch, with the root end just below the soil surface

From sets:

• The quickest to establish but more prone to bolting
• Best planted in March through April
• Sets are better suited for green onions or scallions than large storage bulbs

Onions need well-drained, fertile soil. If your beds tend to hold water through our wet spring months, raised beds can make a real difference. Our guide on building raised garden beds in Kitsap County covers drainage and soil setup in detail.

Caring for Onions Through the Season

Once your onions are in the ground, consistent care through spring and early summer sets the stage for a good harvest.

Watering:

• Onions need steady moisture while developing foliage, roughly 1 inch per week
• Reduce watering in July as bulbs begin to mature and tops start to fall over
• Overwatering during bulb development can encourage rot

Feeding:

• Onions are moderate feeders. A nitrogen-rich amendment worked into the bed before planting gives them a strong start
• Side-dress with a balanced organic fertilizer or compost in late April or May if growth seems slow
• Pull back on nitrogen once bulbs begin to swell, typically June onward

Weeding:

• Onions have shallow roots and compete poorly with weeds
• Keep beds weeded consistently, especially in May and June
• Mulch lightly to suppress weeds without burying the bulb shoulders

Rotation:

• Onions belong to the allium family, along with garlic, leeks, shallots, and chives
• Avoid planting alliums in the same bed within 3 to 4 years to reduce disease and pest pressure
• Follow alliums with legumes like peas or beans the next season to rebuild soil nitrogen. Our guide on growing peas in Kitsap County is a helpful next read

Harvest and curing:

• Harvest when about half the tops have fallen over and begun to dry, usually July through August in Kitsap County
• Cure bulbs in a warm, dry, well-ventilated spot for 2 to 4 weeks before storing
• Storage onions like Copra or Patterson can keep for several months when cured and stored properly

How Roots & Wings Can Help

Growing onions well takes a bit of planning, from choosing the right long-day variety to managing soil drainage through our wet Pacific Northwest springs. At Roots & Wings Gardening, we work with Kitsap County families to build productive, well-planned food gardens that take the guesswork out of growing.

We think in terms of whole systems, not just individual plants. That means your onion bed fits into a thoughtful rotation plan, your soil is prepared to support what you're growing, and your garden is set up to produce season after season.

If you're building out a vegetable garden this year or looking for guidance on what to plant where, we'd be glad to help. Reach out to schedule a consultation with our team.