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You can grow asparagus in Washington State if you pick the right spot and plant at the right time.
The cool, wet climate west of the Cascades is actually perfect for asparagus, and even the drier eastern side can work with a little extra irrigation.
Asparagus is a perennial, so once you get a bed going, it will keep producing spears for 15 to 20 years.
If you have been wondering how to grow asparagus in Washington state, the short answer is: plant crowns in early spring, give them full sun, and be patient for two years before your first real harvest.
In this post, we will walk through how to grow asparagus in Washington state, from choosing the right variety to harvesting your own homegrown spears.
How to Grow Asparagus in Washington State
Growing asparagus in Washington state comes down to three things: location, soil, and timing.
1. Pick a Sunny, Well-Drained Spot
Asparagus needs at least six to eight hours of direct sun each day.
On the west side of Washington, that means finding the sunniest corner of your yard because our cloudy springs can slow growth.
Good drainage matters even more than sun.
Asparagus roots rot in soggy soil, and western Washington has plenty of wet winters.
If your ground stays soggy, build a raised bed at least 12 inches tall.
2. Test and Amend Your Soil
Asparagus grows best in loose, sandy loam with a pH between 6.5 and 7.5.
Most Washington soils are naturally acidic, especially west of the mountains, so you will likely need to add lime.
Work in plenty of compost and a balanced fertilizer before planting.
Asparagus is a heavy feeder, and healthy soil is the foundation of how to grow asparagus in Washington state successfully.
3. Plant Crowns in Early Spring
The best time to plant asparagus in Washington is March through April, once the soil is workable but still cool.
You can start from seed, but crowns are faster and far more reliable in our short growing season.
Dig a trench about 12 inches wide and 6 to 8 inches deep.
Set the crowns 12 to 18 inches apart, cover them with 2 inches of soil, and fill the trench gradually as the spears grow.
Best Asparagus Varieties for Washington State
Choosing the right variety makes growing asparagus in Washington state much easier.
1. Mary Washington
This is the classic heirloom variety and it thrives in our climate.
It is disease resistant and produces reliable, flavorful spears for decades.
2. Jersey Knight and Jersey Supreme
These all-male hybrids produce higher yields because they do not waste energy on seed production.
They are excellent choices for both sides of the state.
3. Purple Passion
If you want something a little different, Purple Passion adds color to your plate and tends to be sweeter.
It is a fun option when learning how to grow asparagus in Washington state.
Caring for Your Asparagus Bed
Once planted, asparagus needs steady care to establish well.
1. Water Consistently
Water deeply once a week during dry spells, especially east of the Cascades.
West of the mountains, you can water less often, but do not let the bed dry out completely in summer.
2. Mulch and Weed
Spread 2 to 3 inches of compost or straw mulch to hold moisture and smother weeds.
Weed carefully by hand because asparagus roots sit close to the surface.
3. Fertilize Twice a Year
Feed in early spring before spears emerge and again after harvest.
A balanced fertilizer or aged manure keeps the bed productive for years.
4. Leave the Ferns Standing
Let the ferny stalks grow all summer.
They feed the crown for next year’s crop, so cut them back only after they turn brown in late fall.
When and How to Harvest Asparagus in Washington
Do not harvest anything the first year, and only a few spears the second.
By the third spring, your bed is ready for a full harvest.
Pick spears when they are 6 to 8 inches tall and snap them off at ground level.
Harvest for about six to eight weeks, then stop and let the ferns grow.
This rest period is the secret to how to grow asparagus in Washington state for the long haul.
So, How to Grow Asparagus in Washington State?
You can grow asparagus in Washington state by planting crowns in early spring, choosing a sunny spot with well-drained soil, and caring for the bed patiently.
Pick the right variety, water and mulch consistently, and resist harvesting too early.
Do those things, and your asparagus bed will reward you with fresh spears every spring for the next two decades.