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Crisp green celery stalks with leaves
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When to plant celery in Walla Walla, WA

Start celery from seed indoors Feb 20 – Mar 6, then plant the young plants in the garden in Walla Walla May 1 – Jun 5.

Tricky here Plant young plants (starts)

Difficulty
Tricky here
Sun
Full sun; light afternoon shade east of the Cascades
Spacing
10 to 12 inches apart
Planting depth
Plant starts at the depth they grew in the pot
Frost
Handles light frost
First harvest
About 100 days after planting

Why these dates

Walla Walla's typical last spring frost is March 27. Celery handles light frost, but a week or two of nights below about 50°F makes young plants bolt to seed, so planting waits until nights warm up, around May 1.

Columbia Basin and low eastern valleys. Hot, dry summers and quick spring warm-up. Warm crops go in earlier than west of the Cascades, and irrigation matters more than rain.

How to grow celery in Walla Walla

  1. Start seeds indoors Feb 20 – Mar 6 in trays or small pots under a grow light or in your sunniest window. Or skip this step and buy young plants (starts) at a garden center.
  2. Harden off the young plants: about a week before planting, set them outside for a few hours a day, a little longer each day.
  3. Plant them in the garden May 1 – Jun 5, 10 to 12 inches apart. Plant starts at the depth they grew in the pot.
  4. Water deeply once or twice a week rather than a little every day, and mulch once the soil is warm.
  5. Harvest: Cut outer stalks as you need them, or cut the whole plant at soil level once the stalks are full-sized, usually from late summer into fall.

Key numbers

Growing notes

What makes the difference in Northwest gardens, in plain language.

Starting celery from seed

Celery seed is tiny and slow. Sow it indoors 10 to 12 weeks before planting time, pressing it onto the surface of the mix without covering it, since it needs light to sprout. Keep it at about 70°F; it can take two to three weeks to come up. Seedlings grow slowly at first, so be patient. Buying starts is a good shortcut.

Why timing matters

Celery is a biennial: it normally makes leaves one year and flowers the next. A week or more of nights below about 50°F convinces a young plant it has been through winter, and it bolts to seed in summer instead of making stalks. That's why the planting dates here wait for warmer nights than other cool-season crops.

Harden seedlings off gradually, and if a cold snap comes after planting, cover them with row cover.

Water, food and blanching

Celery has shallow roots and comes from marshy ground, so it needs water every week of summer. Dry soil gives you stringy, bitter, hollow stalks. Mulch the bed and use a soaker hose. Feed with compost at planting and a balanced fertilizer once a month.

Blanching (wrapping stalks in paper or cardboard for the last two weeks) makes them paler and milder, but it's optional. Many gardeners prefer the darker, stronger-flavored green stalks for cooking.

Common questions

When is the last frost in Walla Walla, WA?

Typically March 27. In 9 years out of 10, frost is over by April 22. These are 1991–2020 NOAA climate normals for Walla Walla Regional Airport.

Is it too late to plant celery in Walla Walla?

The spring planting window runs through June 5. Later plantings tend to struggle in summer heat.

When should I start celery from seed indoors in Walla Walla?

February 20 to March 6, which is 10 to 8 weeks before the May 1 planting date. Or buy young plants at a garden center instead.

Why is my celery bitter and stringy?

Usually not enough water or heat stress. Celery needs steady moisture all season; mulch and water deeply every week.

Why did my celery flower in its first summer?

It got too many cold nights while young. Wait until nights stay above about 50°F before planting out.

Can I regrow celery from the base?

A store-bought base will sprout leaves in water or soil, but it rarely makes full stalks. It's a fun project, not a crop.

Also plant in Walla Walla around the same time

Planting dates for celery in nearby areas

Full planting calendar for Walla Walla · Celery in every city