Growing asparagus plants using a raised bed garden is a great way to go. The vegetable can be expensive to purchase, so growing your own every year can be beneficial.
All you need in your garden is a cool and secluded location where to place your raised bed. From then, you can easily grow this delicious plant. Of course, no gardening is effort-free, and you have to tend to your plants as you would any other crop.
Growing asparagus in raised beds is ideal as it helps these annual plants grow undisturbed year after year. In our gardening guide, you can learn how to make sure your asparagus gardening adventure goes without too many hiccups by not having an ideal raised bed.
By the end of our guide, you’ll see how growing asparagus in a raised bed can set you up for a constant supply. You’ll also learn how to prepare the ideal raised bed for years of healthy growth. (Learn How to Grow Potatoes)
Does Asparagus Do Well in Raised Beds?
Asparagus spears grow exceptionally well in raised beds. There are, however, a few things to know to get the best results. Here are some insights and tips on how asparagus will grow in your raised beds rather than your regular vegetable garden.
- Asparagus will grow unaffected when planted correctly, and doing so means you won’t expel lots of effort to grow delicious plants.
- Plants need spacing about 18 inches apart (1 1/2 feet apart), which is the minimum for the best results; the further apart, the better.
- Because you need a wide area, you’ll need a raised bed big enough to hold the asparagus plants you want to grow. An ideal-sized raised bed should be 12 inches tall, as this depth helps the soil accommodate the plants.
- Asparagus grows best in several inches deep, nutrient-rich soil, and with a correctly prepared raised bed, you can grow asparagus in the same bed for at least ten to 20 years.
- As part of the care, you need to till the soil to a depth of 12-inches. While doing this, add compost into the soil so it’s full of nutrients and can retain water.
- You may only get two rows in a standard 4 foot wide grow bed, though this can deliver great results.
- Before planting asparagus, make cone-shaped piles of dirt that are four- 6 inches high. Place these in the furrow’s bottom, and there are at least 18 inches apart.
- Position your asparagus’ crown on each dirt pile in the furrows to plant it. Plant asparagus roots so that they can drape out over the pile of dirt.
- After you’ve mounted the asparagus, fill your furrows until the crowns are covered with one inch of soil.
- Water your asparagus plants often and keep the surrounding soil moist. Don’t over-wet the soil, although watering asparagus plants is vital for them to grow into tall stalks.
- As your asparagus starts growing, fill the furrows with another couple of inches of soil. In addition, keep covering any developing asparagus spears until your raised bed furrows are filled to the soil level.
- Start harvesting spears in the second or third year, and make sure to choose one that stands more than 8 inches tall. Cut just below the soil line to harvest.
- You will only harvest for two weeks during the first year and then harvesting asparagus plants for four weeks in the next year.
- Cut the plants to the ground level each year when they die back over the winter.
How Big of a Raised Bed Do I Need for Asparagus?
Growing asparagus in raised garden beds offers the ideal seclusion for your controlled growing conditions for perennial asparagus plants.
By using your raised bed, you enable the plant’s development without hindrance from other plants. (Learn When to Harvest Kale)
A raised bed will help reduce weeds and grasses from your asparagus seed and your crops. It is vital to do this as planting asparagus doesn’t compete well with weeds because of the shallow root system.
You can use a 2-foot-wide barrier of landscape fabric or even use a perforated black plastic sheet, then cover this with bark or mulch to help keep pesky weeds at bay.
Raised beds can also present the ideal soil conditions as you need to fill them and tailor them to the needs when you grow asparagus plants.
Make sure you add fertile, well-drained soil that has been amended with plenty of compost, organic matter, or manure.
Plants need at least 18 inches apart for spacing so that a four-foot-wide bed would offer you two rows. A bed that is eight feet long will allow you to plant five plants, In total, you can get ten asparagus plants in a conventional sized raised bed. (Read Mulch For Vegetable Garden)
How Deep Should an Asparagus Bed Be?
Here you can see how to plant asparagus roots as the bed depth is crucial. Asparagus crowns will only be available for harvest once per year in the early spring. (Read How Long Does It Take for Grass Seed to Grow)
Dig a 12-inch trench after your raised bed is weed-free. Add a shovel of compost and a cup of all-purpose, organic fertilizer in your new trench at intervals of 18-inches where you plant your crowns.
How Do You Prepare a Raised Bed for Asparagus?
While asparagus can be grown from seed, it is much easier to plant bare-root crowns directly into the ground. Asparagus crowns are plants that have been dormant for a year. The majority of asparagus varieties are sold as bare-root crowns.
Gardeners traditionally plant bare-root asparagus crowns throughout the spring. However, you plant them in the fall when the soil is colder, which helps your plants establish faster.
After two years, a single row of about 10-12 plants can yield a decent crop. For the very first two years following planting, you wouldn’t be able to harvest your asparagus; you need to let them grow.
Once established; however, each asparagus crown may produce 25 spears annually can harvest for up to 20 years or until you have a 25-year-old plant.
Asparagus needs pH levels of 6.5-7.5; if your soil isn’t in this range, add lime to your raised bed space.
Don’t replant into old asparagus beds using new asparagus crowns. It is a better gardening practice to establish a new raised bed for your perennial asparagus.
In a standard raised bed that is 4 feet wide, dig a trench or two 12 inches deep down the center of the bed. You can follow the planting instructions from above.
Add plenty of well-rotted manure and compost before the previous winter. Adding horticultural grit in preparation can help with soil drainage before you add your plants; asparagus likes moisture but not a soaked garden bed.
Caring for your asparagus crowns does take some attention, yet the maintenance tasks are straightforward. (Read Raised Bed Gardening Layouts)
Here are a few of the tasks you need to do as you go through the growing season and other times of the year.
- Spring: Feed using a general fertilizer every March
- Summer: Keep the plants well-watered during hot periods to prevent them from drying out. Adding mulch can help yet remember asparagus plants have shallow roots so drying out can occur rapidly. Shallow roots can be easily damaged when using a hoe, so you are advised to deal with weeds by hand.
- Fall: Cut back any yellowing foliage as you mulch crowns using well-rotted manure. Doing this adds nutrients and helps protect against frost and stop weeds.
- Winter: Cover the beds with opaque weed matting as this will keep your beds weed-free by stopping weeds from germinating. Your asparagus at this stage won’t be showing much action and won’t until the perennial plants are a couple of years old. It takes a couple of years for new asparagus plants to be ready for harvest.
Asparagus year-by-year harvesting guide
First Year: Resist any temptation to harvest spears in the first growing season. Rather, leave your plants to grow and develop foliage as it encourages stronger and healthier growth.
Second Year: Now, you can harvest a limited crop. Only take around half of the spears during the second year. Cut your spears once they are around 6-inches tall.
Third Year: You can now harvest all spears from your asparagus bed for about six weeks. The time for this is mid-April onward where you would cease cutting toward the end of May.
Limiting this avoids weakening plants and promotes good cropping from your asparagus bed in the years to come.
Year 4 onward: You can harvest asparagus spears for eight weeks from mid-April each year.
Harvest your asparagus beds using a sharp knife when they’re around 6-8 inches tall. Cut to half an inch below ground level. Spears are fast-growing, so check crops every day in the harvest season.