When to plant arugula in La Grande, OR

Plant arugula from seed, directly in the garden in La Grande, Apr 1 – May 13. For a fall harvest, plant again Aug 13 – Sep 3.

Easy Plant seeds in the ground

Difficulty: Easy
Sun: Full sun to part shade
Spacing: Thin to 4 inches apart
Planting depth: ¼ inch deep
Frost: Handles light frost
First harvest: About 35 days after planting

Why these dates

La Grande's typical last spring frost is May 6. As a cool-season crop that handles light frost, this crop doesn't need to wait for that date. In the Inland Northwest, though, the soil usually isn't ready to work until about April 1.

Inland Northwest. Higher, colder interior valleys. Cold springs and an earlier fall mean a shorter season; quick-maturing varieties pay off.

How to grow arugula in La Grande

Prepare the bed: loosen the soil and mix in an inch or two of compost.
Plant seeds Apr 1 – May 13, ¼ inch deep, Thin to 4 inches apart.
Keep the soil evenly moist until sprouts appear, which can take one to three weeks in cool soil.
Plant again Aug 13 – Sep 3 for a fall harvest.
Harvest: Pick leaves when they're 2 to 3 inches long, about three weeks after sowing. Young leaves are the mildest.

Key numbers

40–85°FSoil to sprout
6.0–7.0Soil pH
About 3–5 weeksDays to harvest
Flea beetlesBiggest risk

Growing notes

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

Soil and sowing

Arugula isn't fussy. Ordinary garden soil with a little compost and a pH of about 6.0 to 7.0 grows it well. It sprouts in cool soil, often within a week, so it's one of the first crops you can sow in spring. Scatter seed thinly, cover lightly, and keep the soil moist. Thin plants to about 4 inches apart and eat the thinnings. Steady moisture keeps leaves tender and mild; dry soil makes them tough and peppery.

Why arugula bolts and gets spicy

Arugula is a cool-season green that flowers as days get long and warm. Heat and drought speed this up and make the leaves sharper. Sow small batches every two or three weeks in spring, take a break in midsummer or give it afternoon shade, then sow again in late summer for fall. Fall arugula is often the best, and west of the Cascades it can last well into winter under row cover. Wild arugula (Sylvetta) grows slower, handles heat better and often comes back from the roots.

Flea beetles and harvest

Flea beetles are tiny black beetles that jump like fleas and chew small round holes in leaves, especially in warm spring weather. Lay row cover on right after sowing and seal the edges; damage drops off once plants grow fast or the weather cools. Pick leaves when 2 to 3 inches long, cutting outer leaves or shearing the whole patch an inch above the soil to regrow. If plants bolt, the small white flowers are edible and mild. Store leaves in a sealed container in the fridge for several days.

Common questions

When is the last frost in La Grande, OR?

Typically May 6. In 9 years out of 10, frost is over by May 26. These are 1991–2020 NOAA climate normals for La Grande.

Is it too late to plant arugula in La Grande?

The spring planting window runs through May 13. If you miss it, plant again for fall from August 13 to September 3.

How long until I can harvest arugula?

About 35 days after planting. Pick leaves when they're 2 to 3 inches long, about three weeks after sowing. Young leaves are the mildest.

What is making tiny holes in my arugula?

Flea beetles. They're worst in spring. Cover seedlings with floating row cover from sowing day, and keep plants growing quickly with steady water.

Why is my arugula so bitter?

Heat, dry soil, and age all make arugula stronger. Pick leaves young and keep the soil moist. Spring and fall crops are mildest.

Does arugula grow back after cutting?

Yes, if you cut an inch or so above the crown, it will regrow for a few more harvests. Production slows once the plant starts to bolt. Sow a fresh batch every few weeks for a steady supply.

Also plant in La Grande around the same time

Planting dates for arugula in nearby areas

Baker City, OR Apr 20 – Jun 1
Pendleton, OR Mar 20 – May 1
The Dalles, OR Mar 20 – May 1
Hood River, OR Mar 20 – May 1
Hermiston, OR Mar 20 – May 1
Ontario, OR Mar 20 – May 1

Full planting calendar for La Grande · Arugula in every city