How To Grow Asparagus: All You Need To Know

Ed Wike
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Asparagus: Quick Care Guide

Growing asparagus is extremely easy, however, your asparagus garden needs to be tended on a few different levels in order to ensure your asparagus will grow to maturity. In this article, we'll cover how to grow asparagus from seed and how to keep it healthy during each stage of its life.

Sow in Spring or Autumn

Asparagus seeds are viable for up to three years, so it's wise to store them properly and sow them as soon as the temperatures are just (or are likely to be) above freezing.

Asparagus seeds are extremely small and should be sown 1/8" deep. Asparagus grows best in loose, sandy soil. It can be sown directly in the ground, or in pots in trays. Cover the seeds and keep them moist but not wet.

Asparagus seedlings can be transplanted to the garden after 8 weeks, or when they're the size of a pencil. You can also sow the seeds outside in the fall and let them grow over the winter.

This variety has pencil thin stalks of up to 18 inches. They are best eaten freshly harvested or preserved.

Asparagus plumosus

They grow upright and produce white flowers, which have both male and female parts. They are usually harvested before the fruits appear.

Asparagus officinalis caespitosus

This form grows upright with pencil thin stalks of up to 18 inches. They are best eaten freshly harvested or preserved.

Planting Asparagus

Asparagus is best planted in early spring or late fall. Although, you can skip the whole asparagus growing process and just buy asparagus at the supermarket, two weeks before a hard frost.

Asparagus plants can live for many years and you can plant them even if you live in a colder area and you just need to protect them from frost. In cold climates, start growing asparagus as soon as the soil can be worked.

It is very important to prepare the soil before you begin planting your new Asparagus plants.

Thoroughly remove weeds and grass from the area you have chosen, as weeds may compete with your new plants.

It is crucial to dig a hole that is deeper than the asparagus roots. This way the tops will not be exposed to sun or other harsh weather conditions.

Make sure you water your new asparagus plant a day or two before planting and then set it into the hole. Remember to cover the roots with about two inches of soil.

Water your plants after planting, making sure the ground is moist and not soggy.

Finally, you can mulch the bed with compost or pine needles. This keeps the soil cool and moist around the new asparagus plant.

When To Plant Asparagus

Planting Asparagus is best done during the spring months, but you can sow seeds even in the fall season. Fall planting is carried out around November. The roots will take about two months to get established, while growth will be visible in about four months.

Before planting, choose a suitable location where the asparagus will get at least 6 hours of full sun. Prepare the bed at least 1 year before planting. Asparagus needs a loose, fertile soil, and its roots are very sensitive.

Soil Preparation

It is highly important to create a raised bed for planting. Raise the bed at least 15 to 20 inches above the soil. It is also advisable to add an 18 inch layer of compost or leaf mold. The bed should be 4 to 5 feet wide.

Where To Plant Asparagus

One of the main places asparagus can grow is in the garden. Asparagus is a vegetable plant that grows well in gardens.

It grows best in well-drained soil that is rich in nutrients.

When you are collecting the soil, make sure there are no toxic chemicals or dog poop that might have been left there. If you can collect your soil from a place at least 30 meters or 100 feet away from the other plants, this is even better.

Your soil should be fluffy and crumbly. It should not include any rocks or soil that is extremely heavy.

When you transplant the plant from the place where it started growing to the area where you want to plant it, you will need to dig a hole that is a little more than a foot across and deep enough for you to place the asparagus plant in.

You should place the plant at a distance of about 3 feet from each other.

Asparagus also grows well when you have it in containers on your deck.

There are many varieties of asparagus. The white varieties are best for the garden as they will grow in all light conditions.

When you are in a shaded area, the all green varieties are best for containers.

How To Plant Asparagus

Asparagus is one of the most loved vegetables in the world. It is very tasty, healthy, and it packs a powerful punch when it comes to vitamins and minerals. Asparagus is great for salads, soups, sandwiches, or just on its own. It is also an extremely nutritious vegetable, but few people have the privilege to enjoy it on a regular basis. This is primarily because most are not fortunate enough to have their own source of asparagus plants. In this article you will get to know how to grow asparagus so that you no longer have to settle for eating asparagus from the supermarket.

Asparagus is a green, white, or purple plant that grows best in the spring. Asparagus is best grown in areas where the plants can be grown in full sunlight. The plant itself usually grows up to two feet high. The main asparagus plant has thick, woody, and underground stems. These stems, known as asparagus roots, are where the actual asparagus grows from. It typically takes three years for the mature asparagus plant to be able to be harvested.

Caring For Asparagus

When you grow asparagus, it’s important to keep in mind that they are long-term crops and they need a bit of looking after in order to ensure your quantity.

Asparagus grows from the bottom. When you cut the spears you want to cut about 3-4 inches above ground.

This makes it look like they are growing from the tree or stump as opposed to actually growing from the roots.

You can pretty much grow asparagus in any type of soil, but sandy is the best.

If you are growing your asparagus in a container, you want to be sure that you have a loamy soil which will keep things aerated.

Make sure that your asparagus plants are spaced 3-4 feet apart from each other.

If you get your plants from a local nursery you can ask your salesman how far they recommend to space and grow your plants.

They will also usually tell you if you should be staking your asparagus plants. If your soil is rich in nutrients and if you have a small variety of asparagus then they probably will not need to be staked. If your asparagus get taller than 10 feet, or if you have a big variety you might want to stake them.

Sun

It's easy to grow asparagus. But asparagus is not mature for harvest until three or four years after planting … and even then, it requires some attention to harvest, and of course, to store for future use. Here are a few tips and a bit of trivia for the asparagus enthusiast.

Asparagus plants cannot be harvested for two years after planting. No tilling or disturbing the bed is permitted during that time, or they do not produce. The deep roots have to catch to the soil to begin to grow vigorously.

Plant them early in spring (no later than the middle of May) in a bed that has been well-fertilized.

Since asparagus is a member of the lily family, and since there are companion plants that stimulate growth and repel pests, you'll want to plant your asparagus in the company of some members of the onion and garlic family.

Grow your asparagus plants in good, rich, loose soil that is well aerated. If growing in rows, make the rows a minimum of 12 inches wide, with 24 to 36 inches between each row.

Break up any clods of earth with the back of your hoe, and remove rocks and debris.

Work compost into the bed, and then work in a dressing of 10-10-10 fertilizer.

Temperature

Asparagus grows best in a temperature range of 50Ëš to 75Ëš Fahrenheit.

Temperatures below or above this range slow down or inhibit growth. Avoid planting asparagus near taller trees and plants that produce excessive shade.

If you live in an area that has mild winters, consider staggering your planting schedule to provide continuous crops throughout the year.

Watering

Taking care of asparagus can be a daunting task, especially if it is your first time growing it. It’s best to make sure that you know how to water asparagus properly so it will yield the best possible results. Here’s what you need to know about watering asparagus.

Asparagus does not need a large amount of water. Therefore, deep watering is not needed. It is recommended that you water lightly and consistently. Soaker hoses are the best irrigation tools you can have for asparagus. And you should make sure that the hoses are placed at an even depth so the roots are evenly saturated. If planting in rows, add a longer board that can be used to level the ground before laying the hose.

The watering frequency depends on many factors. The first is the soil quality. If you are creating your asparagus bed from scratch, make sure that you are using well-draining soil. Avoid water retention from the soil at all costs. If you are working with home-made compost or soil, it’s generally a good idea to incorporate some sand in order to improve drainage. So if you live nearby a beach, you can just take some sand home and add it to the compost pile to improve drainage.

Soil

Soil has several elements for the growth of asparagus. Asparagus requires the input of proper amounts of phosphorus, potassium, calcium, magnesium, sulphur, iron and zinc.

Sandy loam is the best soil. You can also grow asparagus in silty or clay soil. The pH levels need to be within the range of 5.5 to 6.5.

A good soil drainage is important. The soil should not be soggy but must be able to drain water when it is completely dried out.

Soil acidity levels are important. They should be within the range of slightly acid to slightly alkaline. Previous lime application is the basic for maintaining alkaline soil.

Soil organic material should be abundant. A good supply of organic material in the soil makes it easier for the asparagus to get the nutrients from it. Good soil structure is also important. To ensure a good soil structure, the soil must contain enough organic material. Soil organic matter can be increased by adding compost or manure.

The best soil structure is achieved with a mixture of fresh material along with well decomposed manure.

Fertilizing Asparagus

Asparagus is a perennial vegetable whose stand is spread over time, usually 8-10 years, through the natural process of division. After this, the plants can be allowed to self-sown, which will create new plant stands.

If you want to keep the plant for longer in the area, you will need to divide it. This will depend on how much harvest you get from the plant. Just keep in mind that once the plant is divided, each piece will need to be fertilized and tended to.

Pruning and dividing Asparagus are best done in the spring months (March-April). You will need to remove the old plants from the garden bed using a shovel. The plant should be divided into sections and then replanted into the garden space to allow the baby plants to establish themselves.

Once this step is complete, you can use cottonseed meal to help fertilize the plant. The exact amount to be used depends on the size of the plant you currently have. If you have a really small garden area and you want the plant to fill the entire space, you will need to fertilize at least three times during the first year.

Pruning Asparagus

Asparagus is a perennial vegetable that can be grown organically. The ideal season is from early spring to late fall but asparagus can be harvested year-round. Pruning is vital for the vegetable’s health and survival. Pruning should be carried out to encourage new growth and to get rid of old wood. All old growth that exists above the soil should be removed for better production. The idea is to make sure that sunlight can reach your asparagus crowns.

Here’s how to prune asparagus:

Asparagus should not be pruned in fall when they produce the phytochemical asparagine. This is not a good season to prune. Wait until May, months after they have begun flowering. Spring is also a good time to prune.

Cut all dead and decaying spears to increase yields.

Cut all vegetation that is below ground level.

Cut back the emerging bright green shoots with a sharp hand pruner at the base of the spear where it meets the main stem. Trim back only the tips, leaving approximately 4 inches of spear below the cut.

When the more tender spears are forming, clip them off.

New spears will grow quickly to replace the ones you have removed.

Cut the old stalks off at the base to extend the harvests.

Propagation

The most common method of propagating asparagus plants is by seeds. Surprisingly, a viable asparagus plant can be grown by the seeds of the first crop. The plant generated by the seeds can be planted in approximately three months. Well, that is not probably what you have heard. The fact is about every fourth triangle is not viable. The mother plant is left after the seeds have been collected. This mother plant is grown on for three more years, and the seeds from that plant are used for the first year of the cultivator. The first year the farmer gets around a hundred seeds per mother plant, and the second year there is a crop of about 325 seeds. That is the way farmers can increase production, because the plants get very vigorous the second year.

The other method of propagation is division. divisions can be made in two or three parts. This method is very useful as it allows the farmer to broaden their crop, and also it offers them the opportunity to raise young plants as protection against diseases and other insects.

Transplanting

Once you have your asparagus patch established, you need to transplant your asparagus seedlings into the patch.

This can be done anytime during the growing season, but it's best to do it in the spring, before your asparagus is up and growing, or in the fall, after the plant has died off for the year. Why in the fall? The biggest reason is the cold.

You don't want to introduce your tender asparagus seedlings to weed killers and the elements during the times when it's cold outside. Having said that, it can take a few weeks for asparagus plants to adjust to their new bods and it can be quite an adjustment as the asparagus plant will go from being a tender little thing to a strong and hardy perennial. Asparagus is quite hardy, and will live for decades in your patch, but it's always best to do it when temperatures are moderate.

If you are transplanting in the fall, you can use a tiller to bury your asparagus in the ground right where it's going to grow. If you are transplanting in the spring, however, you need to use more delicate means.

Bleaching Asparagus

Asparagus is best grown organically, or at least organically if you have the space to be able to make that choice.

To test whether asparagus is ready to harvest, pinch the tip off each spear and peel downwards. If it is firm, then it is ready to harvest. If you wish to store asparagus, then you can put the spears in water before you store them if you are not planning to cook them the same day as harvesting them.

Some people prefer the slightly milder flavor of asparagus that has been bleached by sunlight, while other people prefer the taste of non-bleached asparagus, stating that it tastes fresher.

The milder flavor that is associated with bleached asparagus is more a result of the type of asparagus being either more bitter tasting due to some sort of nutrients, or there is a more foliar residue on the asparagus that results in a slight bitterness in the flavor.

For either reason, if you plan to eat asparagus raw, the preference for whether asparagus is bleached or not bleached is a matter of taste.

Companion Plants For Asparagus

Asparagus is a fine vegetable companion to alfalfa, potatoes, beans, and peas. On the other hand, it cannot be grown successfully with cucumber or squash plants. You are looking for a rich, moist topsoil that is slightly acidic. Asparagus is also suited for areas with poor soils, as long as you are willing to enrich the soil early on. Addressing soil pH and fertilizer is extremely helpful for the roots of the asparagus. The roots of this plant will typically spread out and may go much deeper than you realize. Additionally, asparagus is actually a member of the lily family, along with onion and garlic plants.

Harvesting & Storing Asparagus

Asparagus can grow for years, but it is wise to harvest it when it is in peak condition. You want it to be somewhat short and fat. The thicker, the better to taste it's full flavor. You can eat asparagus that is more than a foot tall, but it will not taste as good.

The specific color of asparagus is not important although most people prefer a spear that is light green or even white. The real test to see if asparagus is good is to gently tug on it. If it snaps off easily, it is ready to eat. It also helps to find a patch that looks healthy.

To store, place them in a plastic bag or container and put them in the fridge. It is not recommended to freeze asparagus because it can kill the flavor.

Harvesting Asparagus

The Asparagus season varies from year to year, depending on the climate and the crop. Because of this, planting and harvesting Asparagus needs to be done on an annual basis. It is possible to keep your Asparagus bed for a few years, by taking steps to prepare it.

Before planting, remove all the existing vegetation from the ground and add nutrients to the soil. Asparagus roots don’t like to grow in compacted ground, and a healthy root system will increase the life of your plants.

Asparagus can be planted from seeds or from sprouts. If you’re choosing to set up your own farm, buy seedlings and plant them in the ground.

Storing Asparagus

Asparagus is most frequently available during the months of March, April and May. Bring them home immediately and store them in the refrigerator. It is better to keep asparagus in the vegetable crisper drawer than in the fridge’s vegetable bin, because they will remain fresher there for longer.

Troubleshooting

  • Asparagus is a gorgeous vegetable plant, but it is pretty particular about where it grows. It grows best in cool soil, and will not do well in dry soil allowing you to get away with merely tilling and top dressing the area.
  • The asparagus spear is made up of thousands of incredibly thin cells growing in layers. The first layer of cells is white while the next layer gradually becomes green. The tip of the spear naturally triggers the green layer to remain green just before it is ready to harvest.
  • To put out a heavy harvest of asparagus spears it is important that the first layer of cells get enough sunlight. Extending the rows of asparagus out to save space is not a good idea as the asparagus plant is a plant that does not like to touch.
  • With proper care, the plants will continue to produce asparagus spears for two weeks in the spring and up to eight weeks in the fall.
  • The fern-like leaves of asparagus are edible. Just be sure never to consume them if they are wilted or black as they contain a poisonous chemical.

Growing Problems

Asparagus is a fussy vegetable. It needs to be consistently watered, well fertilized, and it can’t stand too much shade. Though asparagus seems easy to treat this way, sometimes things go wrong. If you start seeing some discolouration or the spears seem to be deteriorating, here are the usual problems people have with asparagus, and how to fix them.

Pests like aphids or slugs LOVE asparagus too. A good insecticide can eliminate them.

Mold. It’s a common problem that’s difficult to deal with. The best thing you can do with this is to get rid of the moldy portion and probably everything underneath it.

Bare spots. Water the plant well at least three times a month. This will encourage the roots to spread and the vegetation to pop up on the spots that were dry.

Wilting. This is usually a sign of being over-watered, but also may indicate a lack of light. In case the soil is too wet, you have to let the excess water drain or the roots can drown.

Other causes:

Pests

White grubs and slugs are the main pests that cause damage to asparagus. They are the larvae stage of beetles and mollusks, respectively. The good news is that these pests generally have their own issues and therefore are not likely to completely wipe out your crop.

White grubs, for example, are not fond of sun and hot temperatures. They keep underground where it is cooler, since they prefer to stay and reproduce in the same area. They also only prefer asparagus plants in small, young stages.

The most common solution for this is the use of beneficial nematodes. They kill fly larva similar to how soap kills germs. The application is specific to certain locations, but generally speaking, you can spray a few areas throughout your garden to prevent the proliferation of white grubs.

Slugs and other pesky creatures are easier to control with copper tape. You can wrap your plants and the ground around it with a layer of this, which will kill slugs or deter them from coming in contact with the plant.

Neither white grubs nor slugs are a cause for concern if you keep a watchful eye. With a good set of tools, you should be able to limit damage done by these pests.

Diseases

While the listed diseases are the most common ones in asparagus crops, certain diseases which are not yet listed can also infect the crop. Some of these, like Phytophthora crown rot, form a significant enough threat to the crop that fungicides are often applied to the planting.

Frequently Asked Questions

Q. I have several asparagus varieties, do they all require the same growing conditions?

A. No, since there are many varieties of asparagus, each one requires slightly different growing conditions. When planting, keep in mind that the harvest period is key too.

Q. Asparagus is a perennial vegetable. Several years ago, I planted several rows, and now I have a beautiful, well-established planting. Now that my plantings are going strong, how can I extend my harvest time?

A. Simply digging up your plants in the fall for a few weeks will extend your harvest time. As the plants stop growing, simply dig up the crowns and replant them. Because the crowns are healthy and established, they will grow back quickly. You will see the same results the next year.

Q. I planted asparagus in my garden last year, but it didn't produce. What am I doing wrong?

A. Asparagus needs several factors for successful establishment such as well-drained soil, sun, and a consistent soil pH level. Adding compost to your planting bed will supply the necessary nutrients and loosen the soil.

Gardening tip: Test your soil every spring before planting to maintain the correct pH level.

Q: Is asparagus fern the same as asparagus?

A: You are probably conflating two different plants. Asparagus fern (Neanthes asparagoides), also known as asparagus pea, is a perennial climbing plant that resembles the true asparagus. The vegetable asparagus is a kind of lily. It is the fleshy, edible part that should not be confused with the flowering part.

A: As we say, the true asparagus is the edible, fleshy part of the plant. This is a dark, starchy vegetable with a unique flavor and texture. It's grown as a food crop in many parts of Europe.

A: Asparagus fern is a perennial plant that looks quite different than the true asparagus. It has delicate green fronds and it's often used in decorative hanging baskets.

Q: Can you use square foot gardening techniques with asparagus?

A: Asparagus is not easy to grow, so if you do not get the spacing exactly right you may find you are fighting the asparagus to remain within the shape you mapped out or the crop is entirely missed.

If you are looking to grow asparagus organically and are happy to pay a high price for the crop, then this may not be too much of a concern. However if you are looking for a low maintenance crop to fit into an easy gardening plan or are particularly focused on cost-saving methods, then asparagus may not be the right vegetable for you. Instead why not try resistant varieties, perennial plants, or container growing?

For example, if you want to grow asparagus organically, you could try one of the varieties of asparagus that are resistant to asparagus rust such as Jersey Knight and Jersey Giant (recommended varieties).

However none of these are resistant to asparagus fly which can be a real problem for home gardeners.

Q: Can you plant asparagus in a container?

Asparagus grows best in soil that is well-drained and has a neutral pH. A container soil might be heavy on one of the elements. Another problem with containers is they are harder to control for buildup of any particular element. The major limiting element with container gardening is providing adequate space for the feeder roots.

Q: Can you plant asparagus in a raised bed?

Asparagus is not the easiest vegetable to grow. It grows best in rich soil that is well-drained. It is easier to control the chemical composition and drainage of a raised bed. It is easier to maintain good physical structure. Raised beds may still have inadequate spacing for feeder roots, and may present the same fertilizer challenges as container gardening. Raised beds may contain "wood-lining" that will "off-gas" for the life of the bed and slowly poison the plants growing within. Wood-lined beds are the most toxic of all bed types.

Q: Can you plant asparagus in sandy, dry soil?

Since asparagus require a neutral to slightly alkaline pH, sandy soil that is very dry is likely to be too acidic, even if it is rich in nutrients.

Q: Can you plant asparagus in soil with special additives?

Q: Is growing asparagus worth it?