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Asparagus crowns should be buried about 6 to 8 inches deep for the best results.
That said, the exact depth can vary slightly depending on your soil type and the age of the crowns you’re planting.
If you’ve been wondering how deep to bury asparagus crowns, you’re in the right place.
Getting the depth right is one of the most important steps in growing a healthy, productive asparagus bed that lasts for decades.
In this post, we’ll walk through how deep to plant asparagus crowns, why depth matters so much, and the best way to get it right the first time.
Why You Bury Asparagus Crowns at That Depth
When you bury asparagus crowns at the right depth, you set your plants up for years of strong growth.
Here’s why 6 to 8 inches is the sweet spot for planting asparagus crowns.
1. It Protects the Crowns From Frost
Asparagus crowns are perennial, meaning they stay in the ground year after year.
If you bury asparagus crowns too shallow, winter cold can reach them and damage the crowns.
Burying asparagus crowns 6 to 8 inches deep gives them a natural buffer against freezing temperatures.
2. It Encourages Deep Root Growth
Asparagus sends out roots that can reach several feet down over time.
When you plant asparagus crowns deep, you encourage those roots to grow downward in search of moisture and nutrients.
Shallow planting leads to shallow roots, which means weaker plants and smaller spears.
3. It Keeps the Crowns From Drying Out
The crown is the heart of the asparagus plant, and it needs consistent moisture to thrive.
Burying asparagus crowns at the proper depth keeps them cool and moist during hot spells.
This is especially important in the first season while the crowns are getting established.
4. It Prevents the Spears From Emerging Too Early
If you plant asparagus crowns too close to the surface, the spears push up early and often get nipped by late frosts.
When you bury the crowns deeper, the soil warms more slowly in spring, which helps the spears emerge at the right time.
How to Bury Asparagus Crowns Step by Step
Knowing how deep to bury asparagus crowns is one thing, but getting the process right is another.
Here’s a simple method for planting asparagus crowns correctly.
1. Dig a Trench About 12 Inches Deep
Start by digging a trench that’s roughly 12 inches deep.
This gives you room to mound soil at the bottom and still bury asparagus crowns at the right depth.
The trench should be wide enough to spread the roots out without bending them.
2. Add a Mound of Soil in the Trench
Place a mound of loose soil or compost at the bottom of the trench.
Set each crown on top of the mound with its roots draped down the sides.
This positioning helps you bury asparagus crowns at the correct depth while giving roots room to spread.
3. Cover the Crowns With 2 to 3 Inches of Soil
At first, cover the crowns with just 2 to 3 inches of soil.
As the spears grow through the season, keep filling the trench in.
By fall, the trench should be full, and you’ll have buried asparagus crowns at their final 6 to 8 inch depth.
4. Water Deeply After Planting
Give the bed a deep watering right after you bury the crowns.
This settles the soil around the roots and helps the crowns start growing.
Keep the soil consistently moist, but never soggy, through the first season.
Common Mistakes When Burying Asparagus Crowns
Even seasoned gardeners sometimes get asparagus crown depth wrong.
Watch out for these common mistakes when you bury asparagus crowns.
1. Planting Them Too Shallow
The biggest mistake is planting asparagus crowns too close to the surface.
Shallow crowns dry out fast and produce thin, weak spears.
Always aim to bury asparagus crowns 6 to 8 inches deep once the trench is filled.
2. Burying Them All at Once
Many growers dump all the soil back in right after planting.
Instead, fill the trench gradually as the spears grow.
This gradual approach is the safest way to bury asparagus crowns without smothering them.
3. Skipping Soil Preparation
Asparagus loves loose, well-drained soil rich in organic matter.
If your soil is heavy clay, amend it with compost before you bury the crowns.
Good soil prep makes a huge difference in how well your asparagus crowns take off.
4. Forgetting About Drainage
Asparagus crowns rot in waterlogged soil.
Make sure your bed drains well before you bury asparagus crowns, or plant them on a slight ridge.
Raised beds are a great option if your native soil stays wet.
So, How Deep Do You Bury Asparagus Crowns?
You bury asparagus crowns about 6 to 8 inches deep, working up to that depth gradually over the first season.
That depth protects the crowns from frost, encourages deep roots, and helps your spears emerge at the right time.
If you’ve been asking how deep to plant asparagus crowns, the answer is simple: start with a 12-inch trench, cover with 2 to 3 inches at planting, and fill in as the spears grow.
Get the depth right, and you’ll enjoy fresh asparagus from the same bed for 20 years or more.
Happy planting.