Asparagus is a long-lived perennial vegetable that grows in USDA Zones 3-8. It requires rich, well-drained soil, constant moisture, and no weed competition. What better place to grow asparagus plants than in a raised bed, where you can easily fill it with organic matter and control planting conditions! Asparagus can easily live for 20 years, so you need to carefully plan the location of your raised asparagus bed.
The advantage of planning your bed of asparagus is that you can easily control many of the conditions asparagus plants like and easily perform long-term maintenance of your bed. Asparagus can be obtained from seeds, but it is most commonly planted in the garden as two-year-old crowns with long roots.
With a few simple steps, you can prepare for decades of gardening in an easily accessible raised bed! Growing in a raised bed can also help control soil quality and moisture over time. If you want to learn more about the benefits of growing asparagus in a raised bed, read on!
Why an asparagus raised bed?
A special asparagus raised bed is a good choice for the garden. Source: Rigid
There are many reasons why you should grow your asparagus in a raised bed garden.
Soil quality: Since you fill the raised bed yourself, you can use a much higher quality soil than you would use for planting in the ground. It's much easier to change the soil throughout the bed from the start and you have complete control over how much compost and what soil changes you add. In addition, the soil in a raised bed has good drainage, which protects the root system from rot.
Easy maintenance: A raised bed is easier to handle in everyday life, as a raised bed contains far fewer weeds and can be easily pulled by hand. Higher raised beds also require less bending over! You can easily install drip irrigation or a waterer hose system to cut down the time it takes to water your plants.
Protection for perennials: Asparagus will come back year after year so you can easily protect them in a separate bed. So if you need to use raised beds to protect the plants from pests or wildlife, you don't have to worry about harming other plants around them.
Optimization for your type of system: Another benefit of having an elevated asparagus bed is that you can optimize conditions for just asparagus without worrying about other plants nearby. This can include things like your watering and fertilizing schedule, when and how much you mulch, and the types of row covers you use for your plants.
Faster soil warming: This is important because asparagus is often one of the first plants to appear in early spring. To do this, however, he needs warm, protected soil. If you plant in a raised bed, your soil will heat up faster than the soil. You can use different covers to speed up the heating process and protect the plants from sudden changes in temperature. This gives your asparagus a head start over plants that are in the ground.
Style: Raised asparagus beds are not only functional, they also add style to your garden! Since asparagus is perennial, it can be a special plant in your garden. Put your asparagus bed somewhere to show off the wispy asparagus ferns in the summer season or use them as a fun conversation starter!
Longevity: One reason using a raised bed is useful, especially a galvanized steel modular style like the beds in the Epic Gardening store, is because metal beds can outlast wooden beds. A wooden bed will eventually rot and crumble. However, metal beds, especially well-made, should last for decades … just like your asparagus plants!
Easy harvest: Last but not least, it's much easier to harvest asparagus from a high raised bed than it is to pluck it from the ground. In a high bed, you can just walk by and break off spears as they grow!
Asparagus spacing in raised beds
Typically, you would plant asparagus crowns or seeds in rows 18 inches apart, then several feet apart. This protects the delicate root systems and gives the plant plenty of room to spread out and room for you to walk along the rows and access your plants while you care for them.
In a raised bed you don't have to place the "rows" so far apart! Since you can walk around your bed with ease, there are no large rows required to access your plants. You can easily place the asparagus crowns 18 inches from any other plant. This enables a greater density of plants in a smaller space and at the same time offers plenty of room for future growth.
Tips for growing asparagus in raised beds
Here are some tips for growing asparagus in raised beds and how to care for them for epic harvests. There aren't many specialty accessories that you will need.
The location is the key
Choose a spot in your garden where you don't mind making space for growing a perennial vegetable for a long time. Whether you are growing an older plant or starting from seeds, you will care for (and harvest) this plant for a long time.
Start with rich soil. Change your soil with compost before you even plant your plants. This is how you prepare for success! Fill the bed with compost and organic matter. Be careful not to skimp on this part as the asparagus will grow for a long time in this raised garden bed.
Plant asparagus about 30 cm deep in the ground. Asparagus likes to grow in rich soils and over time it consumes the nutrients. Make sure you modify the planting area with organic matter and soil amendments like compost if you haven't already. Use a soil mixture that is rich in organics.
Dig holes 12 inches deep and 18 inches apart. Put the crown or seed in the hole and gently distribute the roots. Gently slide the compost over it and fill in the hole.
Asparagus can also be planted by digging a trench. Plant asparagus in the trench 18 inches apart and cover it with compost and organic matter. The crown should be covered with several inches of earth between 8 and 12 inches. Fill the trench deep with compost and water.
If you are starting out with seeds, be sure to start your seeds in containers so they can form larger roots before planting them out in the garden. Plant seeds just half an inch deep in the ground.
Protect young plants
Asparagus spears stick out of the ground. Source: MrPants
Protect your young asparagus plants. Do not let the crowns dry out while planting and let the bed water well, especially in the first year. If you establish healthy plants in the first year, you can grow better in the following seasons.
In a raised bed, you can add light floating row covers over the bed to prevent the asparagus beetle or other pests from infecting your plants before they become established.
In addition to using floating row covers, you can put a cold frame over the bed in late winter to warm the floor for spring as needed. If you need to heat your floor quickly, use black plastic to trap the sun's heat. It depends on which zone you are growing in.
When the summer sun gets too hot for the asparagus, swap out your floating row cover for a shade cloth to protect the growing fronds.
Grow your asparagus
The asparagus plant takes time to form its roots. When you start seeding, allow three seasons to pass before you harvest spears. If you plant crowns, you can harvest asparagus spears within the first two years.
Once planted, keep your asparagus plants watered with about 1 inch of water per week. You can set up drip irrigation or a waterers hose, or even use buried clay pots to make watering more convenient. In a high raised bed, this becomes even easier as you don't have to bend over!
Don't waste space! Asparagus hates root competition, but you can use the space between your plants to grow plants with shallow roots like spinach and lettuce. The asparagus fronds shade the leafy vegetables and protect them from too much sun. You can also grow herbs like basil and parsley or marigolds and tomatoes that will help ward off asparagus beetles.
Prevent weeds from entering your bed by deep mulching, filling any open space with companion plants or cover crops, and making sure the bed is weed-free by pulling weeds regularly by hand to prevent takeover.
It is better to pull weeds by hand rather than using special machines. Asparagus roots are delicate and you want to protect them from damage.
Weed regularly to protect the delicate asparagus roots from overcrowding or competition. If you are struggling with weeds, consider planting companion plants, as filling the bed with plants will prevent weeds from growing in empty spaces.
Harvesting asparagus is like an art form! For the first few years, you want to harvest few spears within two weeks. Then let the asparagus fronds develop and stop harvesting spears. If you harvest too many spears too soon, your plant will not develop the strong root system it needs to survive.
In the following years, increase the number of weeks you harvest spears by one week. For example, in your third year, you could harvest spears for three weeks, but after that you should stop and allow the plant to grow out its fronds.
The longest time you should harvest your asparagus is ten weeks. Remember, this is a plant that can live for decades. So you want to give her time to recover from the harvest!
Your bed of asparagus won't look like much in the winter months. Source: Livewombat
Once you've harvested your asparagus for the season, let the tall asparagus fronds grow out. This enables the system to store energy for the next year. Once the fronds turn yellow, but before any of the red berries falls off (if you have female plants), cut the fronds within a few inches of the soil.
If you live in a climate with severe winters, leave the fronds in place during the winter for additional frost protection. In the spring, remove the fronds and place them in your compost or discard them to prevent hibernating pests from settling.
Once you've removed the fronds and the soil warms up, apply a layer of compost to encourage your new spring growth.
Mulch heavily to keep the moisture in the soil, but wait until the weather is warmer as mulch actually cools the soil temperature. Your asparagus needs warm soil in order to be able to grow early in spring.
And there you have it! Planting asparagus in a raised garden bed can be a thrilling adventure and has many advantages over planting near the ground. A well-planned bed of asparagus can meet various fertilization, irrigation, and pest control needs. It's easy to access and maintain, especially in high raised beds. Growing this crop should be pretty easy with these tips and tricks!
About the writer Rebecca Hendricks:
Hello, my name is Rebecca! I grew up with plants that are loving, but they haven't always loved me. My grandparents and great-grandmother always let me help out in their gardens from a young age, but I couldn't figure out the gardening all by myself.
For a year I decided to do some research to find out how to grow peppers on my balcony and it worked! I realized that gardening is a skill to be learned, not an innate talent to be born with.
I am a volunteer master gardener in Florida and am currently in my sophomore year flipping my entire lawn yard (front and back) to a mix of native, pollinator and wildlife friendly spots, a food forest and raised beds. I raise Coturnix quails and one day I would like to add chickens to my flock.
I love to share my gardening knowledge with others and am always happy to help!
The green fingers behind this article: