Washington’s varied climate zones require morning glory planting after nighttime temperatures stay above 50 degrees. The Best Time To Plant Morning Glory In Washington depends heavily on where you live, from the mild coastal regions to the colder eastern areas. Getting the timing right ensures your vines bloom beautifully through late summer and fall.
Best Time To Plant Morning Glory In Washington
Morning glories are warm-season annuals that thrive when soil is warm. In Washington, the safe window to plant seeds or transplants is typically from mid-May to early June. But this varies by your specific location and microclimate.
If you plant too early, cold soil can rot seeds. Too late, and you miss the peak growing season. Let’s break down the timing for different parts of the state.
Coastal And Western Washington
Areas like Seattle, Tacoma, and Olympia have milder springs. Here, you can plant morning glories around mid-May. The soil warms faster near the coast.
Check your local frost dates. The last frost in western Washington is usually between April 15 and May 1. Wait at least two weeks after that to plant.
Eastern Washington And Higher Elevations
Spokane, Yakima, and the Cascade foothills have colder springs. The last frost can be as late as mid-May or early June. Plant morning glories here from late May to early June.
Soil temperature is key. Use a soil thermometer. Wait until the soil at 2 inches deep reads 60°F or higher. This usually happens a few weeks after the last frost.
Using Microclimates To Your Advantage
Your garden might be warmer or cooler than the general area. South-facing walls and raised beds warm up faster. Plant a week or two earlier in these spots.
Shady or low-lying areas stay cooler. Delay planting there until the general safe window. You can also start seeds indoors to get a head start.
Understanding Washington’s Climate Zones
Washington has diverse climates. The west side is mild and wet. The east side is drier with hotter summers and colder winters. This affects when you can plant.
Morning glories need warm soil and air. They are sensitive to frost. Even a light frost can kill young plants. So knowing your zone helps.
USDA Hardiness Zones In Washington
Most of western Washington is zones 8a to 8b. Eastern Washington ranges from zones 5b to 7b. Higher mountains are zone 4 or colder.
But hardiness zones only tell you about winter cold. For planting timing, focus on last frost dates and soil temperature. These are more accurate for morning glories.
Last Frost Dates By Region
- Seattle area: April 15 to May 1
- Port Angeles: April 20 to May 5
- Spokane: May 10 to May 25
- Yakima: May 5 to May 20
- Wenatchee: May 1 to May 15
- Mountains (e.g., Leavenworth): May 20 to June 5
These are averages. Check your local extension service for more precise dates. A cold snap can happen after the average last frost.
Preparing Soil And Site For Morning Glories
Morning glories are not fussy, but they do best in well-draining soil. They need full sun to bloom well. At least 6 to 8 hours of direct sunlight daily.
Prepare your planting area a week before planting. Remove weeds and rocks. Loosen the soil to about 12 inches deep. Mix in some compost or aged manure.
Morning glories like soil with a pH between 6.0 and 7.5. You can test your soil with a simple kit. Adjust pH if needed with lime or sulfur.
Choosing The Right Location
Pick a spot where vines can climb. A trellis, fence, or arbor works well. Morning glories also grow well in containers with a support.
Avoid areas with strong winds. The vines can get damaged. A sheltered spot near a wall or fence is ideal.
Soil Temperature Check
Use a soil thermometer. Insert it 2 to 4 inches deep. Wait until the temperature is consistently above 60°F. This is the minimum for morning glory seeds to germinate.
If soil is below 60°F, seeds may rot. Wait a few more days. You can warm the soil by covering it with black plastic for a week before planting.
Starting Seeds Indoors For Earlier Blooms
If you want earlier flowers, start seeds indoors 4 to 6 weeks before your last frost date. This gives you a head start. Transplants are also less vulnerable to cold.
Use small pots or seed trays. Fill with seed-starting mix. Plant seeds 1/4 inch deep. Keep the soil moist and warm, around 70°F.
Morning glory seeds have hard coats. Soak them in warm water for 12 to 24 hours before planting. This speeds up germination.
Transplanting Seedlings Outdoors
Harden off seedlings before moving them outside. Place them in a sheltered spot for a few hours each day. Gradually increase time over a week.
Transplant after the last frost and when soil is warm. Space plants 6 to 12 inches apart. Water well after planting.
Direct Sowing Seeds In The Garden
Direct sowing is easier and works well for morning glories. Wait until soil is warm and frost danger is past. This is usually from mid-May to early June.
Plant seeds 1/2 inch deep. Space them 6 inches apart. You can thin later to 12 inches apart. Water gently after planting.
Seeds germinate in 5 to 14 days. Keep the soil moist but not waterlogged. Once seedlings appear, water less frequently.
Succession Planting For Continuous Blooms
For a longer blooming season, plant a second batch 2 to 3 weeks after the first. This ensures flowers from midsummer into fall.
In warmer parts of Washington, you can plant as late as July. But later planting may mean fewer blooms before frost.
Caring For Morning Glories Through The Season
Morning glories are low-maintenance. But a little care goes a long way. Water deeply once a week if there is no rain. More often in hot weather.
Fertilize lightly. Too much nitrogen encourages leaves, not flowers. Use a balanced fertilizer or one high in phosphorus. Apply once a month.
Train vines onto supports early. They will climb on their own. But you can guide them gently. Remove dead flowers to encourage more blooms.
Common Pests And Problems
Morning glories are generally pest-free. But aphids and spider mites can appear. Spray with water or use insecticidal soap.
Powdery mildew can occur in humid conditions. Ensure good air circulation. Water at the base, not on leaves.
Dealing With Washington’s Weather
Washington summers can be dry east of the Cascades. Water more frequently there. In western Washington, rain is common. But morning glories still need water during dry spells.
If a late frost threatens, cover young plants with a cloth or row cover. Remove it in the morning. This protects them from cold damage.
Best Varieties For Washington Gardens
Some morning glory varieties perform better in Washington’s climate. Choose ones that bloom well in cooler conditions.
- Heavenly Blue: Classic sky-blue flowers. Blooms well in mild weather.
- Grandpa Ott’s: Deep purple with a red star. Very hardy.
- Flying Saucers: Blue and white striped. Tolerates some cool weather.
- Scarlet O’Hara: Bright red. Good for warmer spots.
- Early Call: Mixed colors. Blooms earlier than many varieties.
These varieties are reliable in Washington. They bloom from midsummer until the first frost in fall.
Where To Buy Seeds Or Plants
Local nurseries and garden centers carry morning glory seeds. Look for them in spring. Online seed companies offer more variety.
Check the Washington State University Extension website for local recommendations. They often have tips for your specific area.
Frequently Asked Questions
Can I plant morning glory seeds in April in Washington?
It depends on your location. In western Washington, April is often too early. Soil is still cold. Wait until mid-May. In eastern Washington, April is definitely too early. Wait until late May or June.
What is the latest time to plant morning glory in Washington?
You can plant as late as early July in most areas. But later planting means fewer blooms. The first frost in Washington can come as early as September in some areas. Aim for June for best results.
Do morning glories come back every year in Washington?
Morning glories are annuals in Washington. They die with frost. But they reseed easily. If you let some flowers go to seed, new plants may appear next year. But they are not reliable perennials here.
Should I soak morning glory seeds before planting?
Yes, soaking helps. Morning glory seeds have hard coats. Soak them in warm water for 12 to 24 hours. This softens the coat and speeds up germination. Plant them right after soaking.
Can I grow morning glories in containers in Washington?
Yes, containers work well. Use a pot at least 12 inches deep. Provide a trellis or stake. Water more often than in-ground plants. Place in full sun. Container plants warm up faster, so you can plant a bit earlier.
Final Tips For Success
Timing is everything for morning glories in Washington. Wait for warm soil and no frost. Use a soil thermometer to be sure.
Start seeds indoors if you want earlier blooms. But direct sowing is simpler. Choose a sunny spot with good drainage.
Water consistently but not too much. Fertilize lightly. Train vines onto supports. Enjoy the flowers from midsummer to fall.
Morning glories are forgiving plants. Even if you plant a little late, they will still bloom. Just give them warmth and sun.
Remember that Washington’s weather can be unpredictable. Have row covers ready for unexpected cold. And don’t worry if some seeds don’t germinate. Plant a few extra to be safe.
With the right timing, your morning glories will thrive. They will climb and bloom, adding color to your garden. The key is patience. Wait for the soil to warm. Then plant and watch them grow.
Your garden will thank you. And you will have beautiful blooms all summer long. Happy planting in Washington.