When to plant eggplant in Kent, Renton and Auburn, WA

Start eggplant from seed indoors Mar 1–15, then plant the young plants in the garden in Kent, Renton and Auburn May 10–31.

Tricky here Plant young plants (starts)

Difficulty: Tricky here
Sun: Full sun; the hottest spot you have
Spacing: 18 to 24 inches apart
Planting depth: Plant starts at the depth they grew in the pot
Frost: Killed by frost
First harvest: About 80 days after planting

Why these dates

Kent, Renton and Auburn's typical last spring frost is March 20. Frost kills eggplant, and warm-season crops also need warm soil. Soil here stays cold for weeks after the last frost, so planting waits until about May 10.

West-side valleys. The Willamette Valley, Puget Sound and southern Oregon valleys. Long frost-free seasons, but soil stays cold and wet into May, so warm crops wait for warm soil, not just the last frost.

How to grow eggplant in Kent, Renton and Auburn

Start seeds indoors Mar 1–15 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.
Harden off the young plants: about a week before planting, set them outside for a few hours a day, a little longer each day.
Plant them in the garden May 10–31, 18 to 24 inches apart. Plant starts at the depth they grew in the pot.
Water deeply once or twice a week rather than a little every day, and mulch once the soil is warm.
Harvest: Pick when the skin is glossy and springs back when pressed. Dull skin means it's overripe and seedy.

Key numbers

75–90°FSoil to sprout
Nights stay above 55°FPlant out when
5.8–6.8Soil pH
Flea beetles, cool nightsBiggest risk

Growing notes

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

Soil, warmth and feeding

Eggplant loves heat even more than peppers. Give it well-drained soil rich in compost with a pH of about 5.8 to 6.8, and wait to plant until nights stay above about 55°F and the soil has warmed. Plants set out into cold soil stall and often never recover their pace. Feed with a balanced fertilizer at planting and lightly again when fruit sets. Water deeply and evenly, about an inch a week.

Growing it east vs west of the Cascades

West of the Cascades, eggplant is a challenge because summers are mild and nights are cool. Choose small-fruited, early varieties like Hansel, Fairy Tale and Orient Express, plant them in your hottest spot, and use black plastic mulch and row cover early in the season. Growing in a large dark container against a south wall also works well. East of the Cascades, hot valleys grow eggplant easily. Flowers can drop in extreme heat, though, so steady water and mulch help there.

Flea beetles, wilt and harvest

Flea beetles chew many tiny holes in young leaves and can stunt small plants. Keep row cover on until plants grow strongly, then remove it so bees can reach the flowers. Verticillium wilt, a soil disease shared with tomatoes and potatoes, causes leaves to yellow and wilt on one side; rotate so eggplant doesn't follow those crops. Pick fruit when the skin is glossy and springs back when pressed. Eggplant doesn't store long: keep it a few days in a cool spot, since the fridge can cause brown spots and pitting.

Common questions

When is the last frost in Kent, Renton and Auburn, WA?

Typically March 20. In 9 years out of 10, frost is over by April 8. These are 1991–2020 NOAA climate normals for Kent.

Is it too late to plant eggplant in Kent, Renton and Auburn?

The spring planting window runs through May 31. Later plantings may not have time to produce before the first fall frost, which usually arrives around November 10.

When should I start eggplant from seed indoors in Kent, Renton and Auburn?

March 1 to March 15, which is 10 to 8 weeks before the May 10 planting date. Or buy young plants at a garden center instead.

Why isn't my eggplant producing fruit?

Cool nights are the most common cause in the Northwest, and extreme heat can do the same in eastern valleys. Plants also need pollinators, so remove row cover once flowers open. Small, early varieties set fruit most reliably here.

What are the tiny holes in my eggplant leaves?

Flea beetles. They're worst on young plants in spring. Use row cover until plants are growing strongly, and older plants usually outgrow the damage.

How do I know when eggplant is ripe?

Look for glossy skin that springs back when pressed gently. Dull skin and brown seeds mean it's overripe. Cut the stem with pruners rather than pulling, since the stems are tough and sometimes spiny.

Also plant in Kent, Renton and Auburn around the same time

Planting dates for eggplant in nearby areas

Seattle and Tacoma, WA May 10–31
Everett, WA May 10–31
Olympia, WA May 10–31
Bremerton and Port Orchard, WA May 10–31
Shelton, WA May 10–31
Portland, OR May 10–31

Full planting calendar for Kent, Renton and Auburn · Eggplant in every city