Emerging asparagus shoots signal the arrival of spring.
Garden asparagus or asparagus is a spring vegetable that loves soaking up the sun. It is packed with nutrients such as Vitamin A, C, E, fiber, folate, and more. Mainly grown for its tender shoots or spears, asparagus is a great plant to grow in your garden.
As they are perennial, once established, asparagus can produce delicious spears for more than 15-20 years, sometimes even up to 30 years. In addition, its fern-like foliage makes a stunning ornamental display.
In this guide, we will tell you how to plant asparagus from seeds to growing and harvest.
Best Time to Grow Asparagus
You can start sowing asparagus seeds indoors 12-14 weeks before the last frost date. The best growing seasons for asparagus are from mid-February to May when the soil is warm and workable.
Plant seeds or crowns outdoors in early spring when the soil is at an average temperature of 50 degrees for best results.
Where to Plant Asparagus
Asparagus is a perennial vegetable that keeps coming back year after year. For this, it needs a permanent planting site where it’s left undisturbed and can thrive for more than 15 years.
Plant your asparagus seeds or transplant the seedlings in areas that receive full sun with good aeration. You can either plant them in raised garden beds or containers.
How to Plant Asparagus from Seeds
Here’s how you can plant asparagus from seeds by following the below steps.
- Soak asparagus seeds in water for up to 24 hours before planting.
- Start seeds indoors in seed starter trays or individual peat cups.
- Sow them 1 ½ inch deep in moistened seed starting mix or loose nutrient-rich soil.
- You can expect seed germination between 7-21 days at an ideal temperature of 75 degrees.
- When asparagus seedlings reach 12 inches in height, hardened them off and transplant the young seedlings in a greenhouse or under a floating row crop cover.
- Grow them in these temporary raised beds until the outdoor temperatures are warm between 60-70 degrees.
- Identify the male asparagus plants which produce more spears than their female counterpart, and transplant them to their final planting areas. Female flowers are smaller and shorter than male asparagus flowers.
Tips for Growing Asparagus
Now that you know about the crucial planting aspect, the next step is the maintenance and care of asparagus plants. Read on to find out certain simple but effective tips for growing asparagus plants.
- Plant asparagus crowns during spring when the soil is warm and in areas that receive full sun exposure.
- Dig a trench that’s 8-10 inches deep and 12 inches wide.
- Plant the crowns and cover them at least 2 inches deep with compost.
- Gradually cover them over the growing seasons till the trenches are full but not covering the crown tips.
- Asparagus are susceptible to weeds which can reduce the yield. You can use natural mulch or vegetable garden covers to prevent and contain any unwanted growth.
- Water them 1-2 inches deep per square foot every week. The soil beds need to be kept moist but not waterlogged. Use drip irrigation to avoid overwatering.
- Asparagus requires a consistent supply of nutrients to thrive. You can go for balanced organic fertilizers occasionally during its growing season.
Asparagus can be harvested in its third year after planting. Skip harvesting them in their first and second year, this can allow the crowns to fully develop. It’s ready to harvest when the spears reach 8-10 inches in height with a thickness of ½ and ¾ inches. You can simply cut the spears at ground level with the help of scissors or a sharp knife.
After harvest, fertilize and trim down the ferny foliage to the ground during early summer. By autumn, new asparagus spears will emerge and be ready to be harvested again.
Following are some frequently asked questions regarding asparagus planting, growth, and harvest.
How many Asparagus Seeds per hole
Plant one asparagus seed per hole in a seed starting tray, or peat cups which is 2 inches deep. You can also try sowing 2-3 seeds per hole and then thin out the seedlings later.
What companion plants can be grown besides Asparagus
Grow basil, tomatoes, parsley, and other herbs as companion plants near asparagus. Avoid root vegetable plants as they can disrupt asparagus plants from developing fully.
How long does it take to grow Asparagus
It can take 2-3 years to grow mature asparagus plants. This allows ample time for the crowns to grow and fully develop. Once established, they can be grown year after year.
How many Asparagus spears do you get from one plant
Once the asparagus is ready to be harvested, you can yield 8-10 spears from a single plant. Though, it depends on the planting location, seed type, and other environmental factors.
How do you get rid of Asparagus beetles and other pests
You can use an organic method like neem oil applied on new spears or use insecticidal sprays and soaps to ward off unwanted pests.