I still remember the incredible taste of that first juicy asparagus spear I picked from my own garden. The sweet flavor was unmatched, far superior to the ones I had bought from the store. It was then that I realized the importance of the soil in growing this perennial delicacy. Asparagus requires specific conditions to thrive, and by following a few tips, you can cultivate a healthy and productive asparagus bed.
The Importance of Soil Quality
Asparagus is a unique vegetable because you harvest before letting it grow. The edible spear emerges from the soil, but you pick it while it’s young and tender. To ensure a bountiful crop, pay attention to the soil in your asparagus bed. The plant prefers sandy, well-drained soil, as moisture can lead to root rot and disease. Here are some tips for prepping and maintaining the soil for your asparagus:
1. Load Up on Phosphorus
Asparagus craves phosphorus, which is essential for its growth. To keep the soil phosphorus-rich, consider adding composted manure, bone meal, or rock phosphate as amendments.
2. Hold the Salt
While asparagus can tolerate salt and even thrive in coastal gardens, adding salt to the asparagus bed can harm the soil quality. Avoid this practice to maintain a healthy growing environment.
3. Don’t Rotate Beds
Asparagus prefers to settle in one place for a long time. The plant can live and produce for over two decades, but it dislikes having its roots disturbed. Choose a location where your asparagus can establish its roots and avoid digging or cultivating the soil around it.
4. Keep It Weed-Free
Because asparagus is a long-lived plant, it is crucial to eliminate perennial weeds from the planting area. Invasive weeds like bermuda grass, bindweed, quack-grass, and buttercup can outcompete your asparagus and hinder its growth. Regularly monitor and remove weeds from the asparagus patch.
5. Top-Dress Every Spring
To maintain a healthy asparagus patch, top-dress it every spring. Apply a layer of 2 to 3 inches of composted manure followed by a 2-inch layer of resistant cultivars such as shredded arborist’s woodchips, straw, or finished compost. This top-dressing will provide the soil with nitrogen and phosphorus, suppress weeds, and improve its quality.
6. Fertilize Twice A Year
Asparagus is a heavy feeder. While the spring top-dressing provides nutrients and organic matter, it is beneficial to fertilize lightly in early spring and mid-summer with a high-phosphorus organic fertilizer like fish meal. This will enhance the growth and productivity of your asparagus bed.
7. Minimize Disease and Pest Risk
Well-drained soil rarely experiences disease issues with asparagus. However, fusarium wilt, purple spot, needle blight, and asparagus rust can infect your crop. If these diseases are prevalent in your area, consider planting resistant cultivars recommended by your local extension program. Practicing good sanitation and removing fronds and debris at the end of the growing year can also minimize disease risk.
8. Companion Plant and Cover Crop
Asparagus benefits from being planted alongside perennials like rhubarb and fruiting shrubs. However, make sure to give enough space to minimize competition. Moreover, to improve soil fertility naturally, consider under-seeding the established asparagus patch with a low-growing, nitrogen-fixing cover crop like crimson clover. You can also interplant with phosphorus bio-accumulators like yarrow. Choose the right cover crops for your region to prevent invasiveness.
9. Start Out Right
You can start asparagus from seeds or crowns, with crowns offering beginners a head start. If starting from seeds, sow them directly into well-drained, fertile soil after the last frost. Soak the seeds in cool water or dilute compost tea before planting. If you prefer crowns, plant them in well-drained, sandy soil, and make sure to spread the roots gently. Hill up the soil around the growing crowns as the shoots emerge to promote better growth.
By following these tips, you can grow a thriving asparagus bed that will reward you with delicious spears for years to come. Though it requires initial effort, once established, asparagus will become a cherished culinary treasure in your garden.
