How to Grow Asparagus to Enjoy the Vibrant Spring Vegetable for Years to Come
This edible perennial plant is a delicious investment that can continue yielding tender spears for 15-20 years or more. Use these tips for planting, growing, and harvesting asparagus.
As the weather finally begins to warm up after the winter, one of the first plants to make an appearance in vegetable gardens is asparagus. If you like to fill your springtime menu with this plant's tasty spears, it's well worth it to grow your own. Whether roasted, grilled, or thrown into your favorite recipes, asparagus makes an elegant and nutritious addition to your plate. This perennial plant needs at least a couple years of growing before it will be ready for harvesting, but after that, it will reward you with its vibrant green stems for many springs to come. Here's how to grow asparagus successfully in your own garden.
1. Prepare the Soil and Asparagus Crowns
To get started in your asparagus growing adventure, pick a location in full sun where your plants won't be disturbed over the years. Then, as soon as soil can be worked in spring, dig a trench in compost-enriched, well-draining soil that is roughly 6-12 inches deep and 12 inches wide. Soak the bare-root crowns in water for half an hour, then place them 18 inches apart in the trench. Plant 20 crowns for a family of four asparagus enthusiasts.
Test Garden Tip: Asparagus is hardy in Zones 3-9, but it's best to select varieties designed for your climate. For example, 'Jersey Giant' ($24, Etsy) is a good bet for northern areas with long, cold winters. In warmer regions, try 'UC-157' ($24, Etsy).
2. Cover and Water the Asparagus Crowns
Backfill the trench and firm soil around the crowns with your hands. Water well, making sure the soil over the asparagus crowns stays level with the surrounding soil. Continue watering throughout the first growing season, especially through dry spells, to encourage vigorous root growth.
Test Garden Tip: Good drainage is very important for preventing root rot. If you have heavy clay soil, consider planting your asparagus crowns in raised beds.
3. Keep Pests and Weeds Away
When growing asparagus (or anything for that matter), you'll want to protect those precious starter plants from pests. Asparagus beetles eat spears and foliage, which will damage the plants. If you see beetles or their dark eggs, pick them off and drop them in soapy water. Carefully hand pull any weeds in your asparagus bed (using a hoe or cultivator could damage your plants' tender roots).
Test Garden Tip: Keep weeds at bay with a 4-6 inch layer of mulch applied once the shoots start to appear.
4. Harvest the Asparagus
You'll know asparagus is ready to pick when the spears reach about 8-9 inches tall. To give the plants time to establish deep roots, don't harvest any spears the same year you plant it, and only harvest lightly the next two years. How do you cut asparagus from the garden? Use a sharp garden knife ($10, The Home Depot) to slice through the stems or break spears slightly above soil level. Don't cut the asparagus below the soil because this may injure the buds that will eventually send up new spears. The small stub above the soil will eventually dry up and disintegrate.
Test Garden Tip: Choose spears with tightly closed tips. Once they start to leaf out, they'll become too tough to eat. Stop harvesting once the new shoots are smaller around than a pencil.
5. Maintain Asparagus Foliage
After harvest season passes, the ferny green asparagus foliage will grow 4-6 feet tall. Keep the plants watered, weeded, and mulched all summer. Use an organic, balanced fertilizer ($12, The Home Depot) throughout the growing season, according to label instructions. Cut the stems back to 2-inch stubs in late fall once they have turned brown, usually after a few frosts.
Test Garden Tip: After cutting down the foliage in fall, gently rake away any mulch and add a 2-inch layer of compost. Then rake the mulch back on top. This will provide the plants with nutrients, while continuing to improve the soil.
It may take a couple seasons to start actually enjoying asparagus dishes made from your harvests, but it'll be worth the wait. New to gardening? Be sure to check out this beginner vegetable gardening guide.