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A pile of long purple eggplants
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When to plant eggplant in Ontario, OR

Start eggplant from seed indoors Feb 20 – Mar 6, then plant the young plants in the garden in Ontario May 1–22.

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

Ontario's typical last spring frost is April 21. Frost kills eggplant, so planting starts once frost risk drops, around May 1. Keep row cover or a frost blanket handy for the first couple of weeks, since a late frost is still possible.

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 eggplant in Ontario

  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 1–22, 18 to 24 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: Pick when the skin is glossy and springs back when pressed. Dull skin means it's overripe and seedy.

Key numbers

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 Ontario, OR?

Typically April 21. In 9 years out of 10, frost is over by May 8. These are 1991–2020 NOAA climate normals for Ontario Municipal Airport.

Is it too late to plant eggplant in Ontario?

The spring planting window runs through May 22. Later plantings may not have time to produce before the first fall frost, which usually arrives around October 14.

When should I start eggplant from seed indoors in Ontario?

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 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 Ontario around the same time

Planting dates for eggplant in nearby areas

Full planting calendar for Ontario · Eggplant in every city