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Top Problems Growing Asparagus and How to Fix It

Are you wondering what problems are involved with growing your asparagus plant? You are not alone – it is always hard when you deal with the unexpected. So, what are the most common problems in growing asparagus?

The top problems when growing asparagus are associated with a lack of nutrients, improper care, and environmental damage. The goal is to have the asparagus mature sufficiently to establish itself. These plants require proper maintenance to do that. 

Properly taking care of the asparagus will help you to fix the problems of the crop. In this article, we will take a closer look at the issues that can significantly impact your harvest and how you can prevent these problems for your asparagus. While this list carries a wide variety of problems that you might face when growing asparagus, it certainly does not cover everything:

  • It is drooping, wilting, or falling over
  • It is turning color brown and yellow
  • It looks dead or is dying

Asparagus Plant Drooping, Wilting, or Falling Over

There are many causes as to why your asparagus might be falling over. The most common reasons are listed below.

Plant Maturity / Age

Asparagus plants tend to fall over when they reach maturity. Typically, the more mature they get, the taller they are to grow. Once they grow more elevated, they become “top-heavy” and fall over. It is entirely normal for them to fall over because of their weight. Most reach heights of 4 to 5 feet along with 2 to 3 feet widespread. 

As asparagus grows taller, the top part starts to produce more energy for photosynthesis. The plant stores the energy in the buds and roots for the next year. There is supposed to be enough energy stored for the next harvest. The energy is also used to produce the edible “spears” on the plant. 

Further, when asparagus plants fall over, it is their way of spreading seeds to create new plants. When the plant goes to seed, the female plants might show red berries, which contain seeds.  

Environment

In some cases, the problem can simply be that the plant is in the wrong environment. Below are some of the most common sources that can affect the environment, which will create further problems for growing asparagus. 

Sunlight

Are you putting your asparagus plants in an area where they will get enough sun? These types of plants need at least eight hours of sunlight per day. If they are not getting enough sunlight, they will grow higher to reach more sunlight. Of course, the higher they grow, the more prone they are to falling over. 

Soil

It is important to get the correct soil for asparagus. They have a deep root system that starts to establish while they are young. The type of soil needed will have to be light, loose, and high in nutrients as asparagus crops are heavy feeders and will be in place for a long time. Make sure to compose and fertilize when necessary. If these plants are not properly taken care of, they will show distress by drooping or falling over. 

Asparagus Plant Frost

It is a common problem when asparagus plants frost. Asparagus will start growing in the spring and continue through the summer and fall. However, once winter hits, they will frost. This affects the plants as they become black and start to wither. They will also fall over. 

But, it is important to remember that asparagus plants are perennials, meaning that they live longer than two years, so when they fall over, the only part that really dies is the “spears.” The roots will continue to live until the spring when they will once again start to grow. 

Humidity

When it comes to asparagus plants, you do not want the environment surrounding them to lack humidity. A lack of humidity will cause the asparagus plants to become yellow and result in the plant drooping or wilting. If the problem is not remedied, then the plant will begin to die as well. A key to maintaining your crop is to keep the soil moist but not overwatered. The water will increase the humidity in the atmosphere surrounding the crops. 

Asparagus Plant Turning Brown and Yellow

When asparagus plants change color, there is always an underlying reason as to why. Listed below are common reasons as to why asparagus plants may change color, particularly to brown and yellow.

Disease

Asparagus have several diseases that afflict them. It is frustrating when these diseases start to destroy the crop. The main conditions that you should be aware of include the following.

Rust

This fungal disease causes rust-colored (orange to reddish-brown) spots on the foliage of the asparagus. This disease attacks the asparagus after harvest and is spread by rain and wind. This disease develops in three stages: The light green lesions turn orange with hollow centers, the lesions then burst and release the rust-colored spores, and finally, the lesions blacken. 

The condition continues to weaken the asparagus’ stems, which leads to death. To avoid your asparagus getting rust, it would be beneficial to apply fungicides to prevent the disease from occurring in the first place. It would also be wise to provide the plants with an adequate amount of water and make sure not to overwater as this can further spread disease. 

Asparagus Plant Purple Spot

This fungal condition is characterized by sunken lesions that turn from tan to brown on the asparagus spears. As the brown lesions begin to expand and grow, they will kill the affected plant. Eventually, the disease will cause defoliation. 

Purple spots can devastate between 60 to 90 percent of the plant’s spears. Experts suggest applying fungicide in the summer months to prevent any purple spot from appearing during the winter. The colder months are when the disease is most likely to occur.  

Root Rot

This is a soil-borne disease that affects the lower stem of the asparagus. The plant becomes infected when plants are stressed by drought. Spears on the plant will weaken, wither, yellow, brown, and then die. 

The fungi in the soil can stay dormant for long periods (up to 30 years!), so it is best to minimize stress by adequately watering and fertilizing the plant. You do not want the asparagus crops to become vulnerable to the disease because it will shorten the production fields’ lifespan by approximately 50 percent.  

Crown/Spear Rot

Asparagus suffering from spear rot can be identified by the wet soils and brown, watery lesions near the soil line. This disease interferes with the crop’s ability to gain nutrients and water. Further, the disease causes the plant to form yellow-orange tissue. 

Since it is a soil-borne disease, it will impact all of your crops. To prevent this spear rot from occurring, you will want to apply fungicides and make sure that you use disease-free soil. The best soil would prevent overwatering so that it does not lead to this type of rot. 

Pests

There is a wide variety of pests that can affect the coloring of the asparagus plants. Let us take a look at the most common ones below. Keep in mind that this list is not exhaustive of all the types of pests that could change coloring and damage to the plant.

Common Asparagus Beetle

If you find that your asparagus plant is browning and there are black stains on the shoots, you will probably find the common asparagus beetle to blame. These guys like to feed on the ferns, leaving them scarred and brown. Further, there is damage to the photosynthetic tissue of the plant. 

You will want to look out for oval-shaped, off-white larvae or adult beetles that are creamy yellow with black spots. The best time to find these beetles is when they are active in the afternoons. You will find that both the adults and larvae chew on the ferns most during that time. The best way to prevent them is by continually monitoring their presence and applying insecticides where there are larvae or damage.  

Asparagus Plant Aphids

If your crop starts to show a green-blue appearance, then you might have an asparagus aphid infestation. These aphids inject toxins into the plants as they feed. Typically, this will cause the asparagus plants to stunt their growth and distort their branches. There will be a reduction in root growth as well, which will likely kill the seeds needed for reproduction. 

Aphids are systematic in how they feed, starting with the spears and moving on to the ferns. This is how they can weaken the growth of the plant. Aphids can be spotted by common characteristics of bluish-gray, powdery textured insects. Cornucles protrude from their abdomen, making them easily recognizable. They also work in clusters. 

Spider Mites

Damage produced by spider mites will appear as small yellow, brown spots on the leaves or stem of asparagus plants. They suck the plant juices, which is how they cause a stippling effect. If the plant is completely infested, it will develop completely yellow leaves and could stop growing. 

As their name suggests, they are tiny to see with the naked eye. If you think that spider mites might be a problem, you can try placing a piece of white paper underneath the foliage and shake the plant. If there are mites, they will typically land on the paper and look like little specks of pepper. Another trick worth trying is to spray the crops with insecticides before the infestation, as you might be too late if you wait too long.  

Spotted Asparagus Beetle

One of the most common signs of work from a spotted asparagus beetle is the browning at the plant’s tip. Over time, the infestation will also lead to the plant wilting from fungal disease due to being vulnerable to the damage the beetle’s cause.

If you wonder how the spotted beetle is different from the common beetle, the most significant difference is that the spotted beetle is not as destructive. These beetles feed on mature asparagus plants, while common beetles feed on new, growing plants. So, there is still room for growth with the plants. Further, spotted beetles can be identified by their reddish-orange coloring and 12 black spots on their back. 

Asparagus Plant Looks Dead or Is Dying

Water 

Asparagus plants have a deep root system, which continues to grow as they establish themselves. However, this does not mean that the plants do not need water to survive. Since asparagus plants do not usually show signs of water stress, knowing how much water your plants need can be frustrating. There is a fine line between overwatering them and underwatering them. To maintain an adequate amount of water, it is best to keep the soil moist. 

Soil

Placing the asparagus plant in the right kind of soil is important. You do not want the plants to lack any necessary nutrients. Experts recommend loose, well-draining soil. This is so the soil does not retain any water and does not lose nutrients. Your plant can have trouble growing if there are not enough nutrients; however, problems can also occur if there are too many of the wrong nutrients. 

If, for example, you have too much nitrogen, your plant can burn, or it could cause other nutrient deficiencies. An all-purpose fertilizer contains three of the most important nutrients for asparagus plant growth: potassium, phosphorus, and nitrogen. Some gardeners prefer to use an all nitrogen fertilizer as it promotes greater growth and strength, but this might not be the best course of action, as mentioned above. It is best to get your soil tested to find the right one. 

Over-Harvesting

You do not want to rush your first harvest. It is best to wait a minimum of 2 years before you do. If you overharvest asparagus plants, they will have less energy to store in their roots. Younger plants and older plants are the most vulnerable at that point. This is because the younger plants need time to mature and establish their roots, while older plants might not store as much energy because their reproduction ability has been impacted over the years. 

If the plants are overharvested, fewer ferns will result, which means less reproduction and growth the following year. The best way to prevent overharvesting is to save some of the spears so they will carry on to the next year. 

Skilled gardeners suggest the following stages of harvest for asparagus plants:

  • First-year: Do not harvest anything. Let the plant grow so it will store more energy in its roots. 
  • Second-year: You can harvest up to one week. Then, leave most of the spears to continue to grow into ferns. 
  • Third-year: You can harvest for 2 to 3 weeks. Any remaining spears should be left to grow and store future energy. 
  • Fourth-year and later: The typical time to harvest is between 6 to 8 weeks. After that, you will want to continue what you did in previous years by leaving the rest to grow and store energy. 

Once plants reach the ten-year mark, you may need to get them replaced. This is best for increasing your yield. Older plants will continue to become more vulnerable to disease, pests, and the elements. However, if they remain strong and well-producing, then you should not worry about replacing them.

What Are the Best Ways to Keep My Asparagus Plant Healthy and Sprouting?

The following list is essential in growing a successful asparagus plant.

Planting

When it comes to planting your first crop, and all others afterward, you want to start with a healthy, disease-resistant plant. It should be placed in well-drained, neutral pH soil and in a site that receives at least eight hours of sun. The asparagus should be planted 6-feet deep and 18 to 24 inches apart in the spring. If you want to yield more asparagus, you will want to plant more male plants than the berry-filled female plants. 

Care

You always want to keep your asparagus as healthy as possible. The best ways to do that are by cutting back the foliage and keeping them weeded.

  • Cut back foliage. Do not cut foliage when it is still green. However, if it is dropping leaves or starting to fall over, you can cut them down 2 inches. It is best to wait until after the first frost when they are yellow. 
  • Keep them weeded. There is weed competition with asparagus plants. You will want to persistently weed or prune the weeds so they do not cover the asparagus. In the winter, you can place mulch or straw to protect them.  

Final Thoughts

It is always challenging trying to know what problems to look out for when growing asparagus. But the most common things to look for are: 

  • Negligence
  • Poor environmental conditions
  • Infectious diseases or pests

These are all problems that can be fixed. The key to healthy asparagus is taking care of your crops and taking the time to prevent any damage that may occur. 

Additional Reading

A bed of asparagus can keep sustaining your asparagus needs for 15 to 20 years. To achieve this level of productivity with the plant, you have to let them mature sufficiently.

The top problems when growing asparagus primarily have to do with improper care, lack of nutrients, and incorrect planting. Asparagus needs to establish deep roots, and they also require the right temperatures to reduce the chances of dormant growth.

Taking care of these elements helps you to fix the problems with your asparagus crop. Below are the main issues that you will encounter with your asparagus plants.

Diseases

The asparagus have several diseases that afflict them, and this can be very frustrating for the gardener. The main conditions that you should look for in an asparagus crop include the following.

Purple Spot

This disease is characterized by oval-shaped, sunken purple lesions that occur on the spears of the plant. Purple spot can devastate nearly 90% of asparagus spears. You will notice the asparagus has brown lesions mainly on the fern and the needle-like leaves.

The brown lesions begin to grow and merge, effectively killing the affected plant. Eventually, the disease causes defoliation in the entire crop. An asparagus plant with purple can still be consumed because the disease doesn’t affect the texture or taste of the vegetable.

However, if you are planting the asparagus for commercial purposes, the brown lesions are unsightly affecting the marketability of the crop. When left unchecked, purple spot can drastically reduce the yield by even up to 50%.

To control the disease, you need to apply fungicide during the summer months. Applying the fungicide during the warm months treats the soil and the plant in preparation for the colder months when purple spots tend to appear. Purple spot is scientifically known as Stemphylium vesicarium.

Rust

Also referred to as Puccinia asparagi in scientific circles, this disease causes the plant to develop rust color on the ferns. It develops in three stages:

  • Oval light green lesions that turn orange with sunken centers
  • Lesions burst and released rust-colored spores
  • The lesions become blackened during the overwintering period

Rust causes the stems to weaken, affecting their growth and eventually leading to the death of the stem. To mitigate rust in your asparagus crop, you can plant varieties that are resistant to the disease. Also, apply fungicides to prevent the occurrence of the disease in the first place. 

You can also spray the fungicide on the crop after harvest to treat the condition.

Also, it is crucial to make sure that the plant is adequately watered during the summer and spring periods. Too much feeds the disease, so avoid getting too much water on the ferns and leaves. 

Overcrowding the plants in the bed also encourages rust as the soil doesn’t get enough aeration.

Root Rot

Root rot also affects the lower stem. The scientific name for this disease is Fusarium moniliforme/oxysporum f.sp. asparagi, depending on where the rot occurs. It can be identified by russet-colored lesions that occur on the lower stem and roots of the plant.

This disease occurs mainly in plants that are stressed by drought. The plant begins to yellow on the fern, and there is a reddish-brown discoloration of xylem. Also, the feeder roots rot off completely.

To prevent the disease, you need to plant clean seeds in non-infected soil. The fungi that cause this disease can tend to stay dormant in the soil for long periods of time. The plant is sensitive, so minimize any stress due to drought. Maintain crown vigor by adequately watering and applying the right fertilizer. Finally, do not overharvest the crop because thin plants become vulnerable to such disease.

Spear Rot

Spear rot can be identified by the water-soaked and soft lesions on the shoots of the plant. Shoots suffering from spear rot can be found right above or below the soil level. The disease, also known as Phytophthora spp., makes the asparagus plant get yellow-orange tissue, which is fibrous and waterlogged. Spear rot occurs during the wet months like heavy spring rains.

Unfortunately, because a soil-borne fungus causes it, if you plant your crop in affected soil, this disease will impact your yields. You must always make sure that both your transplants and the soil you are using are disease-free. Also, choose soil that has excellent drainage to prevent overwatering. Too much is a leading cause of waterlogged tissues.

Being a fungal disease, you can control it by application of fungicides specifically developed to combat the disease.

Asparagus Frost

Asparagus plant frost is a common problem that affects young plants. This condition affects the plant just as it emerges from the soil, causing it to turn black and shrivel. Such plants are entirely inedible.

However, you can combat asparagus frost by cutting off the damaged emerged parts and mulching the plant to keep it warm. Also, adding compost is effective, but make sure it is organic compost. The mulch or compost must be at least eight inches over the crown of the plant to protect it from the cold weather.

Pests

The various pests that affect the asparagus plant require different strategies to combat them. However, frequently weeding the garden is considered to be the one strategy that works across the board when dealing with all the pests. Here are the common pests that find their way into your asparagus crop.

Common Asparagus Beetle

The asparagus beetle is extremely destructive to the crop, causing asparagus plant browning. This is because they feed on the spears of the plant, leaving them scared and brown in color. The beetles eat the leaves meaning that the number of leaves on the plant decreases. A plant with fewer leaves is more vulnerable to Fusarium.

You may notice the beetles in the early stages of the plant’s growth as it is emerging. Look out for spears with oval-shaped, dark brown eggs or white larvae. The beetles are most active in the afternoons, so this is the best time to check your crop for their presence. An asparagus plant eaten by these beetles will typically have a bend in the tip, forming a hook.

In case there is a presence of asparagus beetles, spray the crop with insecticide. Keep in mind that pesticide will affect beneficial pollinators like bees, which may visit the plant when it is in bloom. Spraying in the morning or evening prevents the bees from coming in contact with the insecticide.

If you have a small garden, you can handpick the adult beetles and their larvae and drop them in soapy water. Regularly check your garden because the beetles have wings and can fly into your garden.

Asparagus Aphids

Asparagus plant aphids are typically little greenish-grey insects of about 2mm that have a waxy exoskeleton. Like other aphids, they occur in clusters, but they don’t have the characteristic cornicles protruding from their abdomen.

These aphids are systematic in the way they feed on the asparagus. They begin with the spears where they interfere with new growth and then move on to the ferns. By feeding on the new growth, they shorten the internodes making the plant look like a witch’s broom.

Aphids also deplete the sugar in the plant resulting in weak root growth. Soon enough, the plant is unable to take in sufficient levels of nutrients causing the plant to wilt. Aphids are an active threat to young, unharvested asparagus plants under the age of three years.

An asparagus crop that has an aphid infestation will have a green-blue appearance. These pests affect the yield of the crop, and they are also vectors for diseases like asparagus virus I and II.

Rose Chafer

These pests feed on the flowers and fern of the asparagus plant. In fact, in all plants, the main diet of the rose chafer is the flower blossoms. Unfortunately, they don’t just eat the flowers on asparagus. They also have a toxic substance in their body that can kill birds, poultry, and other small vertebrae if they ingest the bug.

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They tend to enter the crop in early spring by flying into your garden. It is crucial to keep an eye on the crop at all times. You can prevent them from entering a small garden using cheesecloth, which you drape all over the garden. Alternatively, use an insecticide to kill them off if the infestation is out of control.

Tarnished Plant Bug

These bugs suck the plant juices out of the asparagus leading to the necrosis of the area they feed from. The asparagus plant is one of the many plants affected by an infestation of this bug. Their larvae curl into a C-shape when disturbed.

In the case of the tarnished plant bug, it is vital to clear the area around the asparagus bed for weeds. These bugs are attracted to flowering plants and only infest your crop when the weeds around begin to dry and stop flowering. By removing the nearby weeds, you prevent the bugs from coming anywhere near your crop. The alfalfa plant also attracts them.

The tarnished plant bug is an excellent flier so it can be in your garden in and out, leaving behind damaged plants. Asparagus not growing due to tip die-off is likely a victim of this bug.

The Spotted Asparagus Beetle

This beetle is not as destructive as the common asparagus beetle, but that doesn’t mean it is not a menace. The larvae of this beetle feed on the mature asparagus, unlike those of the common beetle, which tend to feed on the new spears of younger plants.

One of the main signs of a crop under attack from this beetle is asparagus with browning at the tip. With time an infestation will result in the asparagus wilting due to fungal disease and other pathogens finding a weakened plant.

Japanese Beetle

Like the tarnished plant bug, these pests also have C-shaped larvae, but they overwinter in the soil and not on the plant itself. As the season changes into the warmer winter, the larvae find their way into the root system of the asparagus plant and begin to feed on the plant.

They soon emerge from the soil as adults and become a menace for the entire fern season of your asparagus crop. The focus for most people when dealing with the Japanese beetle is the adult period, but remember that they are still active as larvae. You can mitigate these using pyrethrum based insecticide of essential oils like neem.

However, if you have a small bed of asparagus and you want to go all-natural, consider handpicking them and dropping them in soapy water. Having said that, natural methods may not be very effective when dealing with Japanese beetles because they typically attack your crop in large numbers causing severe damage. 

These pests have a short lifespan of only 40 days, but their damage can be extensive. They devour the foliage part of the asparagus, which includes the leaves and the spear, leaving the rest looking skeletonized. The larvae leave the roots of the plant weakened, resulting in an asparagus plant dying.

Age-Related Issues

Very old and very young asparagus do not yield much harvest. Some experts advise that you should not harvest an asparagus crop for at least two years to give it time to mature and establish its roots. After this, the plant can give you a better harvest.

Plants older than ten years may need to be replaced, especially if you want to increase your yield. Older plants probably have survived pest, and disease infestation and their reproduction ability may have been affected negatively. The stronger ones can remain, but the weaker ones must be completely removed.

Poor Soil

It is crucial to get the right soil for an asparagus crop because they are heavy feeders. This is extremely important because the plants will be in place for a long time. The soil should be high in nutrients, so it must be infused with organic compost and the right type of fertilizer for asparagus.

An all-purpose fertilizer will work well because it contains the three most essential nutrients for plant growth: nitrogen, phosphorus, and potassium. Some gardeners like to add on an all nitrogen fertilizer to help the plant to become stronger and also to promote rapid growth. Adding nitrogen fertilizer to young plants is an excellent course of action.

Competition

Asparagus beds tend to attract perennial grasses and other weeds that compete for nutrients with the plants. As a result, you may have asparagus plants not growing as you expected. Removing the competition gives the new plants a chance at healthy growth.

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Perennial grasses are especially stubborn because of their extensive root system that deprives young asparagus plants of the much-needed nutrients to establish a sound root system. You can get rid of them by spit treating the bed with glyphosate. This is an effective herbicide that kills off unwanted plants.

For the common weeds, all you need to do is to use a hoe to till the land and remove them. Take to this practice every so often in the summer and spring to protect the crop. However, make sure you do this lightly to avoid damaging the emerging spear of your asparagus.

Wilting and Drooping

Low levels of humidity can cause asparagus plants with drooping leaves. Because the lack of humidity also causes the stem of the plant to become yellow in color, it can cause the asparagus plant to look dead. Fortunately, this is a situation that can be remedied by increasing the levels of humidity as long as the plant isn’t too far gone.

Keep the soil moist but not overwatered to maintain adequate levels of humidity. If the asparagus is in a portable pot, you can place the container on a tray filled with pebbles and water. As the water rises, it increases the humidity in the atmosphere around the plant.

Incorrect Planting Depth

There are two ways to plant asparagus: as seeds or as crown transplants. The seeds should be planted indoors for a short period until the seedlings can be transplanted into the main field. Plant the seedlings at a depth of 2-3 inches (5-8cm) and two inches (5cm) apart.

Crown transplants also need to be planted at 2-3 (5-8cm) inches of soil. In both cases, as they continue to grow, you should add 1-2 inches (3-5cm) periodically until they are covered at a depth of up to five inches. This protects the seedlings and the crowns from issues like frost.

Final Thoughts

The asparagus is a highly nutritious vegetable that is loved for its dense taste. You just have to look out for:

  • Unhealthy growth conditions
  • Poor cultural practices
  • Negligence

All these are problems that you can overcome, and the result will be a bumper harvest from your crop over many years to come. And the best part is once it has grown in place all you have to do is treat it right.

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