Do you want to grow periwinkle in Washington, but don’t know when to plant them?
Planting periwinkle is not as easy as it seems.
- Periwinkle are not able to survive frost or cold weather under 50 degrees Fahrenheit.
So if you plant them outside too early in the fall they will die. And if you plant them too late, your periwinkle won’t produce a bloom.
Today, I’m going to teach you the ideal time to plant periwinkle in Washington:
- To Learn More About HOW to Grow Periwinkle, Check Out This GUIDE!
When to Plant Periwinkle in Washington
As you may have already guessed, you need to pay very close attention to your local weather in the fall. Specifically, you are going to need to watch when the last frost occurs.
In general, when there hasn’t been a frost for two weeks, you are SAFE to plant your periwinkle outside in Washington!
For your reference, I have created this table for average frost dates for most major cities in Washington. If your city is not listed below you can find its Last & First Frost Dates HERE.
Washington Last & First Frost Dates
Unfortunately, Mother Nature plays cruel tricks on us every year.
It should be noted that the above dates are just averages.
There are years when the last frost comes MUCH later. Sometimes, the last frost happens much earlier and you can get your periwinkle planted outside in Washington much quicker.
Like I said before, you need to be very diligent in checking your local weather.
So what happens if a frost comes AFTER you plant your periwinkle?
When you know a frost is coming you need to take action.
- If periwinkle are in pots, bring them inside
- If periwinkle are in the ground, cover them in burlap and hope they survive
Also, make sure not to plant your periwinkle in your garden too late.
- Planting periwinkle too late will cause small blooms or even worse, no blooms.
When Should You Start Your Periwinkle Seeds Indoors?
Depending on the type of periwinkle, it takes roughly 14 to 21 days to grow periwinkle from seed indoors and then transplant them to your garden. And then another 10 to 12 weeks to bloom!
For a specific date that you should start periwinkle seeds indoors you should:
- Find the last average frost date HERE
- And then subtract 14 days from it
Not only this, but I recommend again paying close attention to your local weather report.
It should also be noted that the best technique for bringing your periwinkle plants outside is to introduce them (in their pots) outside for an hour. And then increase the amount of time they spend outside each day by an hour until they have been outside for 8 hours.
This will “harden” your periwinkle plant, increasing its chances of fighting off diseases, insects, droughts, and wet conditions.
If you want to learn WHEN to plant ANY Flower in Washington, head over to HERE and just type in the flower you want to grow.