- How to Grow Asparagus in a Container Garden
- 17 Apart
- Potted Asparagus Plants – Can You Grow Asparagus In Containers
- Potted Asparagus Plants
- Growing Asparagus in a Planter
- Planting Asparagus
- Mulching and Watering
- Starting Asparagus From Seed
- Solving Pest Problems and Defects
- Harvesting Asparagus
How to Grow Asparagus in a Container Garden
asparagus image by William Berry from Fotolia.com
Asparagus is one of the few perennial vegetables available to the home gardener. The plant produces shoots, referred to as spears, in spring and early summer. Then it is allowed to produce foliage for the rest of the gardening season, as the foliage helps replenish the roots for next year’s growth. Since asparagus lives for so long, planting it in a permanent bed can be problematic if your garden design changes or if you move often. Plant asparagus in containers to free up garden space while still enjoying this vegetable.
Set a planter in an area that receives full sunlight, preferably on the south side of the home in an area that isn’t shaded by trees. Use a container that is at least 30 inches deep and 20 inches in diameter. Use only planters that have drainage holes on the bottom.
Mix a soil-less potting mixture with a 10-20-10 analysis, slow-release fertilizer, following the label instructions for exact application rates. Soil-less mixes consist mainly of peat moss and compost, and drain better than soil mixes.
Fill the container to within 8 inches of the rim with potting mix and fertilizer combination. Sprinkle a superphosphate fertilizer at the rate recommended for a single plant on top of the soil.
Set the asparagus crown on top the soil, placing it in the center of the soil surface root-side down. Cover the asparagus crown with enough soil so that the bottom of the crown sits about 6 inches beneath soil level.
Water the container from the top until the excess moisture begins to drain from the bottom of the pot. Asparagus shoots will begin growing within a week. Water thereafter when the top 1 inch of soil begins to feel dry. This may be daily during hot weather.
Fertilize plants once a month beginning in the 10th week after planting. Use a water-soluble, balanced fertilizer at the rate recommended on the package. Fertilize until the asparagus dies back in fall, then resume in spring when new growth appears.
So! We’ve been successfully growing asparagus in containers over the past couple of weeks, something we’ve wanted to do for years, and can’t wait to share all the details here on the blog.
You may remember earlier this month we were over the moon to discover a small patch of wild asparagus just starting to emerge from the ground during a weekend trip to the country:
Since that trip and the small bunch of spears we brought home to cook with, we couldn’t shake the idea of trying to grow fresh asparagus ourselves. We’re always on the lookout for new edible perennials to add into our garden mix and asparagus has been our list for years. We actually thought we’d planted asparagus last spring, but now realize what we thought were asparagus, were probably asparagus ferns (seen in the red pot below) — the ornamental variety. #Fail #Keepingitreal
Since we’re in the ideal asparagus planting window of early spring, we decided to try again. After a quick search, we found Plant World, an Etsy shop in North Carolina specializing in established asparagus crowns and other edible perennials. We’ve purchased plants online before (like our fiddle leaf fig, rubber plant and climbing rose), so figured we’d take the chance and give them a go, opting for the smallest bunch of 5 Jersey Knight root crowns.
They are established 2-year crowns and we’ve read that the Jersey Knight variety is one of the most adaptable to any soil and region. Not even a few days after placing the order, a huge batch of root crowns arrived at our doorstep — here’s what 2 look like:
They were dirty and a little stiff, but we could visibly see where little white nubs were already poking up from the top of the root system — these little nubs are the starts to asparagus.
To plant, we portioned out the crowns 1-2 per container and created mounds of a compost/soil mixture to rest the top of the crowns on, fanning out the roots down and around the sides.
After topping the crowns with more compost mixed soil, we gave them a good watering and set them in the sun to get acquainted in their new home. After about 3 days in the soil, we noticed some of the formerly white nubs beginning to emerge from the soil, turning purple and taking the shape of an asparagus spear.
After a full week, it was undeniable that we had asparagus:
At this stage, the spear was too small to snap off (they are perfect at 6-8 inches in height and about the thickness of a pencil) and we had a trip up to NYC on the schedule, so we wished the plants well and were eager to see their progress when we got back.
Upon returning home only 8 days later, that little asparagus start had already grown from spear stage into the fern formation and we now have 2 more spears emerging, for a total of 3:
We’ve heard asparagus can grow up to 6 inches in a single day when the conditions are right, but were definitely surprised to see it in person. It definitely makes sense why harvesting is recommended every day to few days when the seasonal window is open.
We’re both really happy to have successful plants in containers and aren’t as worried about harvesting them this year. We’ve also heard that 2-3 year crowns are best for a beginning harvest, so we are happy to give these guys a year in their new environment to get happy before reaping the edible benefits next spring.
We’ll most likely just let the spears that emerge continue to grow and reach that full fern formation, which we’ve heard is critical to the success of the next season’s growth. The tips should turn feathery and continue to grow throughout the summer, providing essential nutrients to the roots for next year.
So that’s how we’re faring with growing asparagus in containers — gotta say we’re pretty proud. We’ll look forward to watching for new spears and be sure to keep you updated with the progress.
Potted Asparagus Plants – Can You Grow Asparagus In Containers
Asparagus is a hardy, perennial crop that serves as a wonderful addition to formal kitchen gardens, as well as permaculture food forests. Once plants have become established, gardeners can expect yearly crops of tender asparagus shoots. The introduction of new cultivars has made the process of growing and caring for these plants easier than ever before. But can you grow asparagus in a pot? Read on to learn more about container grown asparagus plants.
Potted Asparagus Plants
Ideally, asparagus plants are grown outside in garden soil in USDA zones 4-8. Thriving in deeply cultivated and consistently moist soils, growers can expect to harvest from plants for upwards of twenty years. Ample garden space is key to growing healthy asparagus, as the plant’s root system can grow quite large.
Fortunately, for those of us growing in tight spaces, there is another option. Whether gardening on a small apartment balcony or simply not in the position to plant long-term perennials, asparagus may also be grown in containers. When planting asparagus in a pot, however, there are a few considerations one must take into account.
Asparagus plants are quite slow-growing when compared to other kitchen garden plants. When grown from seed, the plants will require at least 2-3 years to become established. During this period, the plant should not be harvested. This long waiting period is the main reason that many gardeners choose to purchase plants in the form of asparagus crowns. Simply, crowns are plants that have already been grown for 1-2 years. Therefore, decreasing the waiting period between planting and harvest.
Though growing asparagus in containers is beneficial as a space-saving technique, it will negatively impact the life span of the plants. When growing asparagus in a planter, gardeners can expect only 2-4 seasons of actual asparagus harvests after the establishment period has passed.
Growing Asparagus in a Planter
In the early spring, select a container. For each crown, choose a large container at least 18 inches (46 cm.) deep and 12 inches (30 cm.) across. Planting in larger containers is essential, as asparagus crowns must be planted deeply.
Create drainage holes in the bottom of the pot if none are present. While most planters will already have drainage holes, many gardeners choose to add additional drainage to pots. This will help to prevent the growth of fungus, as well as root rot.
Fill the bottom two inches (5 cm.) of the pot with gravel. Then, fill the remainder with a mix of high quality potting soil and compost.
Plant the asparagus crown into the container by following the package instructions, most often, planting the crown about 4-6 inches (10-15 cm.) deep. Water well. Place outdoors in a sunny location that receives at least 8 hours of sunlight each day.
After planting, shoots should appear within a week. Allow the plants to grow and become established during the first two seasons. Mulching around the plants will ensure that there is no competition from weeds, and that the soil remains adequately moist.
Since these perennials are hardy, leave the containers outdoors throughout the fall and winter. Dormant plants will resume growth in the spring when the weather begins to warm.
Beloved for its delicious young shoots, asparagus is one of the first crops of spring harvest. Growing asparagus is a boon to your health too, as this perennial vegetable is rich in B vitamins, vitamin C, calcium, and iron. And it just so happens that fresh-picked spears are far more tender and tasty than store-bought asparagus.
Asparagus thrives in any area having winter ground freezes or dry seasons. In fact, the mild, wet regions of Florida and the Gulf Coast are about the only places where it’s difficult to grow asparagus. Here’s everything you need to know about growing asparagus, whether you start from seed or spear.
Select and prepare your asparagus bed with care — this crop will occupy the same spot for 20 years or more. It can tolerate some shade, but full sun produces more vigorous plants and helps minimize disease. Asparagus does best in lighter soils that warm up quickly in spring and drain well; standing water will quickly rot the roots.
Prepare a planting bed for your asparagus, like this simple raised bed, that’s about 4 feet wide by removing all perennial weeds and roots and digging in plenty of aged manure or compost.
Asparagus plants are monoecious — meaning each individual asparagus plant is either male or female. Some varieties of asparagus, such as Jersey Knight and Jersey Giant, produce all male or primarily male plants, so they’re more productive — male plants yield more harvestable shoots because they don’t have to invest energy in producing seeds. Choose an all-male asparagus variety if high yield is your primary goal.
If you like to experiment, you may also want to grow an heirloom asparagus variety or a purple-stalked variety like Purple Passion. With an all-male variety, 25 plants are usually adequate for a household of four; plant double that amount for standard varieties. (Ardent asparagus lovers recommend tripling these quantities.)
Starting asparagus from one-year-old crowns gives you a year’s head start over seed-grown plants. Two-year-old crowns are usually not a bargain. They tend to suffer more from transplant shock and won’t produce any faster than one-year-old crowns. Buy crowns from a reputable nursery that sells fresh, firm, disease-free roots. Plant them immediately if possible; otherwise, wrap them in slightly damp sphagnum moss until you are ready to plant.
To plant asparagus crowns, dig trenches 12 inches wide and 6 inches deep (8 inches in sandy soil) down the center of the prepared bed. Soak the crowns in compost tea for 20 minutes before planting. Place the crowns in the trenches 1½ to 2 feet apart; top them with 2 to 3 inches of soil. Two weeks later, add another inch or two of soil. Continue adding soil periodically until the soil is slightly mounded above surface level to allow for settling.
Mulching and Watering
Apply mulch to smother weeds, which compete with the young spears and reduce yields. Carefully remove any weeds that do appear. Water regularly during the first two years after planting. As asparagus matures, it crowds out most weeds and sends long, fleshy roots deep into the earth, so watering is less critical. Fertilize in spring and fall by top-dressing with liquid fertilizer (such as compost tea) or side-dressing with a balanced fertilizer.
Leave winter-killed foliage, along with straw or other light mulch, on the bed to provide winter protection. Remove and destroy the fern-like foliage before new growth appears in spring; it can harbor diseases and pest eggs.
If you want to grow white asparagus, which has a slightly milder flavor than green asparagus, blanch the spears by heaping up soil or mulch over the bed before they emerge.
Starting Asparagus From Seed
It takes patience to start your asparagus patch from seed, but there are advantages to gain from the extra wait. Seed-grown plants don’t suffer from transplant trauma like nursery-grown roots, and you can buy a whole packet of seed for the same price you’ll pay for one asparagus crown. Most seed-grown asparagus plants eventually out-produce those started from roots. Growing from seed also allows you to selectively discard female asparagus plants and plant an all-male bed, no matter what variety you choose to grow.
In the North, start seedlings indoors in late February or early March. Sow single seeds in newspaper pots, place the pots in a sunny window, and use bottom heat to maintain the temperature of the mix in the pots at 77 degrees. When the seeds sprout, lower the temperature to 60 to 70 degrees. Once the danger of frost is past, plant the seedlings (which should be about 1 foot tall) 2 to 3 inches deep in a nursery bed.
When tiny flowers appear, observe them with a magnifying glass. Female flowers have well-developed, three-lobed pistils; male blossoms are larger and longer than female flowers. Weed out all female plants. The following spring, transplant the males to the permanent bed.
Solving Pest Problems and Defects
Healthy asparagus foliage is necessary for good root and spear production. Asparagus beetles, which chew on spears in spring and attack summer foliage, are the most prevalent problem. The 1/4-inch-long, metallic blue-black pests have three white or yellow spots on their backs. They lay dark eggs along the leaves, which hatch into light gray or brown larvae with black heads and feet. Control by hand picking; spray or dust seriously infested asparagus plants with an insecticidal soap.
These methods also control the 12-spotted asparagus beetle, which is reddish brown with six black spots on each wing cover. Asparagus miner is another foliage-feeding pest; it makes zig-zag tunnels on the stalks. Destroy any infested ferns.
Avoid asparagus rust, which produces reddish brown spots on the stems and leaves, by planting resistant cultivars. Minimize damage from Fusarium wilt, which causes spears, leaves, and stems to be small with large lesions at or below the soil line, by purchasing disease-free roots and using good garden sanitation. Crown rot causes spears to turn brown near the soil line. Prevent crown rot by planting in raised beds, maintaining good drainage, and keeping soil pH above 6.0.
If your asparagus bed does become infected by disease organisms, your best option is to start a new bed in a distant part of the garden, using newly purchased or grown plants.
If young spears turn brown and become soft or withered, they may have been injured by frost. Cover spears with mulch or newspaper when freezing nights are predicted.
Don’t harvest any asparagus spears during the first two years that plants are in the permanent bed. They need to put all their energy into establishing deep roots. During the third season, pick the spears over a four-week period, and by the fourth year, extend your harvest to eight weeks. In early spring, harvest spears every third day or so; as the weather warms, you might have to pick your asparagus twice a day to keep up with production. Cut asparagus spears with a sharp knife or snap off the spears at, or right below, ground level with your fingers.
Growing asparagus in pots from crowns takes patience. This vegetable is a perennial plant that produces an edible stem. They need lots of sun, with at least 8 hours of full sun a day.
Asparagus needs lots of room for their roots, and thus the pot size will limit the number of plants within a pot. A pot size of 20 inches deep by 20 inches in diameter is needed for one plant. Ensure your pot has several drainage holes in the base.
Planting asparagus from crowns will allow for harvesting much quicker than seeds. Mix together equal parts of potting soil, compost, sharp sand and aged manure. Dig a hole 6-8 inches deep and 14-18 inches wide. Add a mound of compost at the center of the hole to cradle the roots. Spread the roots evenly over the mound and cover the crown with 2 inches of soil, just to hold the roots in place. When the shoots start to appear, add more soil until the hole is full..
Keep the ground moist but not wet. Overwatering will cause root rot that can kill your plant. You can fertilize with a 0-20-0 fertilizer according to package instructions or choose compost for an organically grown asparagus.
Growing asparagus from a crown will allow you to harvest two years after planting. The plant will deteriorate in yield and health if it is harvested earlier. In the first year let the asparagus produce bushy stems and cut the asparagus to ground level in October. In the second year of growing asparagus in pots, rake the soil and give your plant a small amount of fertilizer in the early part of spring. It is best if you mulch your asparagus with compost to keep it nourished and protected from weeds. Still, do not harvest your spears. Once in the third year you are now able to harvest spears, but leave the very thin spears on the plant to produce ferns. This will help your plant build up strength to produce even more spears for the next year. You can harvest the spears when they reach 4 to 5 inches in length, then cut them a few inches beneath the soil. Only harvest up until mid-summer to give the plant time to replenish for the following years growth.
A good website that describes in detail how to grow vegetables in containers is:
Good luck growing your asparagus.