Rainline Garden
When to plant zinnias in Ephrata and Quincy, WA
Plant zinnias from seed, directly in the garden in Ephrata and Quincy, Apr 29 – Jun 10.
- Difficulty
- Easy
- Sun
- Full sun
- Spacing
- 9 to 12 inches apart
- Planting depth
- ¼ inch deep
- Frost
- Killed by frost
- Flowers
- Blooms about 60 to 75 days after sowing
Why these dates
Ephrata and Quincy's typical last spring frost is April 22. Frost kills zinnias, so planting starts once frost risk drops, around April 29. 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 zinnias in Ephrata and Quincy
- Prepare the bed: loosen the soil and mix in an inch or two of compost.
- Plant seeds Apr 29 – Jun 10, ¼ inch deep, 9 to 12 inches apart.
- Keep the soil evenly moist until sprouts appear, which can take one to three weeks in cool soil.
- Harvest: Cut when stems are stiff right below the flower (give it a gentle wiggle test). Cut long stems often; the more you cut, the more they bloom.
Key numbers
- 70–80°FSoil to sprout
- 5.5–7.5Soil pH
- 60–75Days to bloom
- Powdery mildewBiggest risk
Growing notes
What makes the difference in Northwest gardens, in plain language.
Wait for warm weather
Zinnias come from hot, dry regions and do nothing in cold soil. Seeds sown too early west of the Cascades often rot, and seedlings sit stunted and yellow. Sow once the soil is warm and nights are mild, usually late May to early June on the west side. They catch up fast: a sowing in early June often blooms by midsummer.
You can start them indoors a few weeks early, but transplant them young, since older seedlings don't like root disturbance.
Pinching and cutting
When a young plant is about a foot tall with three or four pairs of leaves, pinch out the top just above a leaf pair. The plant branches, and those branches give more stems and longer ones for cutting.
Cut flowers often and cut deep, down to a leaf pair low on the stem, so new branches have room to grow. Check for ripeness with the wiggle test: a stem that stays stiff just below the flower will last in the vase, while a floppy one wilts quickly.
Mildew, and east vs west
Powdery mildew coats leaves with white powder in late summer, when warm days and cool, damp nights alternate, a typical west-side pattern. Space plants for airflow, water the soil instead of the leaves and choose resistant varieties like Zahara. It looks bad but rarely stops flowering.
East of the Cascades, zinnias thrive in the heat and mildew is less of a problem, though steady water keeps them blooming. Slugs on young seedlings are the bigger west-side issue.
Common questions
When is the last frost in Ephrata and Quincy, WA?
Typically April 22. In 9 years out of 10, frost is over by May 6. These are 1991–2020 NOAA climate normals for Ephrata Municipal Airport.
Is it too late to plant zinnias in Ephrata and Quincy?
The spring planting window runs through June 10. Later plantings may not have time to bloom well before the first fall frost, which usually arrives around October 17.
When do zinnias bloom?
Blooms about 60 to 75 days after sowing. Cut when stems are stiff right below the flower (give it a gentle wiggle test). Cut long stems often; the more you cut, the more they bloom.
Should I pinch my zinnias?
Yes, for cut flowers. Pinch the top when plants are about a foot tall; they'll branch and give many more long stems. Skip pinching on dwarf bedding types.
What is the white powder on my zinnia leaves?
Powdery mildew, a fungus common in late summer. Remove the worst leaves, water at the base and give plants more room. Next year, try resistant varieties like Zahara.
Why don't my zinnias last in a vase?
They were likely cut too early. Use the wiggle test, cut in the cool of the morning, strip the lower leaves and change the water often. Zinnias prefer clean water without much floral preservative.
Also plant in Ephrata and Quincy around the same time
Peas
Radishes
Lettuce
Carrots
Beets
Kale
Broccoli
CabbagePlanting dates for zinnias in nearby areas
- Yakima, WA May 15 – Jun 26
- Tri-Cities (Pasco, Kennewick, Richland), WA May 4 – Jun 15
- Walla Walla, WA Apr 25 – Jun 6
- Moses Lake, WA May 4 – Jun 15
- Ellensburg, WA May 15 – Jun 26
- Sunnyside, Grandview and Prosser, WA May 8 – Jun 19
Full planting calendar for Ephrata and Quincy · Zinnias in every city