Asparagus Garden Perennials

Growing Asparagus

The succulent young shoots of asparagus is something asparagus growers look forward to in the warm days of spring.  If you’ve only experienced canned asparagus you won’t relate to that since fresh asparagus are as far from the canned ones as day is from night.

While writing this post I spoke to one of TMG’s readers on the phone.  Forty years ago, she and her husband purchased his parent’s homeplace in the foot hills of Virginia’s mountains. Twenty years prior to that, her mother-in-law planted an asparagus bed to which my reader has added several roots. Every year she adds composted manure from her horses that is free of residual herbicides.

The bed is still producing after 60 years!!

If you don’t have asparagus and if you’ve been gardening for a while and have improved your soil to where it’s friable, loose and rich in organic matter you’re ready to plant an asparagus bed.

With a little patience you’ll have a planting that provides tender, succulent asparagus spears for many years to come. Even if your bed doesn’t produce for 60 years you can probably certainly count on 15 years or more.

Spears of asparagus coming up in April (and also a ‘weed’ that needs pulling.)

How Many?
About 10 roots are suppose to be enough for 1 person.  I have about 30 plus roots in my asparagus bed.  Every day there is good growth, I pick and eat asparagus during the 8 week season. This amounts to about 45 to 50 days, with some days yielding a double amount.

If there are 2 or more in your family, start out with 24 plants if you have the room.  If you don’t have much room, start with 10 roots to at least give you a taste of this delectable vegetable each year.

What Kind?
I would recommend the predominantly male plants of Jersey Knight that put energy into producing spears rather than berries and seeds. (update Jan. 2017 – I no longer recommend hybrids.  See this post.)

I also have a few of purple asparagus that in my garden are always bigger than the others.  It’s been so long since I planted that I have forgotten their name — but I think they were (are) purple passion.

Planning Your Bed
When you plan your bed don’t crowd it and leave at least 3 feet between rows (4 feet is better) that run parallel to it.  The powerful roots of asparagus can spread laterally for several feet over the years and they don’t like competition from weeds or other deep and long rooted vegetables.

If you’re not ready to plant, but are planning for next year, till in organic material such as compost or manure the fall prior to planting.  Or – try sowing a green cover crop like buckwheat or vetch. And till it in before it blooms to serve as organic matter.

Soil that is friable, loose and rich in organic matter insures good growth.


When you plant in the spring, take care not to expose the roots to the drying sun or wind.  If you’re going to plant more than one row, cover the roots before going on to the next row.

There is quite a bit of information now about planting at various depths (some very shallow and some deep) to extend the harvest.  I recommend only planting deeply.  Planted deeply, the roots can draw in the necessary moisture especially after their first season. This seems to me a good precaution especially in an area where drought is common.  (For an update on my thoughts about “only” planting deeply see this post.)

In addition, I’ve noticed that roots tend to work their way up and don’t necessarily stay at the planted depth.

When you plant:

  • Dig a trench in your prepared bed that is at least 10 inches deep. (In the past I’ve planted even deeper.)
  • Pull 2/3 of soil from the trench onto one side of the bed.
  • Pull the other 1/3 onto the other side.
  • After planting, push in the 1/3 to cover the root.
  • Mulch lightly just to protect the soil
  • As the roots produce spears, fill in with the other 2/3 soil. (An update on this here.)
  • Mulch heavily.

Length of Harvest

Basic Rule of Thumb regarding Harvest:

First Year (from seed)- Do Not Harvest
Second Year (First year crowns)- Harvest 2 weeks is sometimes ok’d.  (I didn’t harvest at all.)
Third Year (Second year crowns)- I’ve seen 4 weeks recommended.  I prefer less.  No longer than one week.
Fouth Year (Third year crowns) and Following Years – Harvest 8 weeks.

There are always circumstances that require different judgments. Let the size and number of shoots determine the actual harvest. Do not harvest small slender stalks pencil size or less.

I have several roots that are not in a good spot.  They have spread into underground wire (placed to deter digging by rabbits and groundhogs) at the edge of the garden.  In addition, roots from our neighbors trees that are many yards away, continually try to encroach that section of the garden and compete with plants.

Asparagus don’t like either situation. In the spring these particular roots send up pencil thin stalks while the rest of my asparagus are twice or three times bigger.  I don’t pick these small stalks.  Later in the season, they start sending up good sized stalks which I harvest.

There are other ways to handle the above situation:

I could go ahead and pick all the stalks that these roots send up if I was not concerned about loosing them.  (I have another asparagus bed planned for this year.  So eventually it will not matter about these several roots.)

Also I could move the roots if I wanted,  although I might have to treat them as if they were a first year plant.

Extending Harvest

By the time spring arrives, most of the thick layer of straw and leaves that I applied last year have dwindled to a thin layer, but still enough to protect my soil.  If I don’t apply additional mulch, the asparagus will come up earlier than if the bed were heavily mulched. But I usually go ahead and mulch deeply in the interest of time and getting the job done.

It’s not usually possible to harvest everyday, since asparagus spears don’t grow on the cold days in spring, but I harvest everyday they grow. Spears grow quickly when its warm.  If you miss them one day, they may be two feet tall the next day and past time to harvest.

A morning’s harvest.

How to Harvest

Snap or cut the asparagus at ground level.  Be careful not to injure tomorrows spears which are now buds just below the surface.  Harvesting at 5 to 8 inches will give you spears that are tender.  If you harvest at 8 to 12 inches you’ll have to cut the tough bottom part off.

One precaution:  As the season progresses high temperatures and continued harvesting will cause the roots to produce a lot.  This can lead to an eventual decline in the vigor of the plant, but you can prevent this by keeping the soil cool.  If you haven’t already done so, this would be the time to apply  an even  thicker layer of mulch. It will slow production to normal and increase the spear size.

Asparagus Beetle.

These little beetles have in the past been the bane of my asparagus bed. If they get out of control they will strip the ferns and even more importantly can greatly reduce the following year’s yields.

I start watch for the little monsters the minute the spears start showing themselves.  I watch the new spears for tiny little black eggs that stick up maybe 1/16 of an inch.

If you’ve havested the spear you can easily rub or wash them off after you get them inside.  If it’s a spear that is going to be allowed to grow, gently rub them off when you see them.  Check everyday.  Believe me once they’ve had a population explosion it can be a nightmare.

After the ferns start to grow, continue checking for eggs, adults and larvae. Although larvae are about 3/8 inch long  and dark grey they can be hard to see on the ferns. Be diligent everyday.  Look, find and smush.   The most rewarding days will be when you don’t have any asparagus beetles, eggs, or larvae.

I had to wait until my asparagus were of harvesting age to experience that wonderful feeling.  There was one year that I didn’t see any beetles.  Last year there seemed to be a lot.


  • Hand picking is the best control.
  • Lady bug larvae and one of the mini-wasps help control larvae.
  • Plant tomatoes in bordering rows.  They help.
  • Tansy growing close by helps.
  • You can use Pyola or Insecticidal soap for bad infestations, but be careful because it will kill beneficials and bees as well. Last year I sprayed once when the beetle larvae got out of control.  I sprayed in the evening when bees are not active and I don’t think I did any damage to anything but the beetle larvae. Still — I am careful not to be lulled into the false security of thinking that just because a product is considered ok for organic gardeners that it isn’t at all harmful. The ideal is not to spray at all. And never spray when the ferns are filled with small bees working the asparagus.

My asparagus fronds in the back ground are so thick a cuke is climbing them. Tomatoes are planted close by. This was taken in July in drought.

Removing the foliage

The asparagus ferns are needed to make the energy that the roots store. Thus, never cut or remove the foliage until the asparagus is completely dormant.  That can be as late as February in my garden.  Fern tops will be dry and yellow.  Cut stalks at the base.

Conventional wisdom says to remove from the bed because the stalks might harbor asparagus beetles.  Years ago I use to do that. Now,  I just cut them a bit so they’re manageable and leave them in a path or on top of a bed to decay.

If you have not already done so, add a thick layer of mulch, leaves, and/or composted manure to your beds.  I no longer have access to manure, but decaying straw and leaves has added enough organic matter to my soil to keep my asparagus happy.

Final Words

If you don’t have any asparagus planted, I would encourage you to order now and prepare a permanent bed for them prior to their arrival.  Time goes so quickly and by ordering now you will be a year closer to enjoying this delicious and healthful vegetable.


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  • Hi there. I enjoyed reading your information about asparagus. I’m puzzled, though. I’ve had several asparagus plants in my garden for more than 5 years and have not had a harvet yet. The spears are very thin then turn into a fern. What am I doing wrong?

    – Cheryl (hungry for asparagus)

  • Hi Cheryl,
    Although some asparagus put up thicker spears than others, you should after 3 years be getting nice size spears for the most part.
    You first need to evaluate how you prepared your bed and soil. Did you prepare as indicated in the post? Also, asparagus do not like heavy clay soil unless it has been greatly improved to a loamy consistency. And of course, they love lots of organic matter in the soil. And they like have a nice bedding of mulch to preserve the greatly needed moisture in summers heat.

    They do not like competition and need to be in an area that they can do their thing. (See details in the post.)

    Here’s another example of something that would decrease their size: — After more than a decade – the neighbor whose property borders ours allowed the field bordering our property to grow up into horrible “trash” trees. After 3 years of growth they are sending roots more than 30 and 40 feet into our property AND into my garden. We just found out this year that the roots have gone under our asparagus beds and the size of our spears in all beds were greatly diminished this year. If we can’t resolve that problem — we may eventually loose our asparagus. (Needless to say — we will be working on it.)

    By the way, just in case you don’t know — all spears (not harvested) turn into ferns. The ferns feed the root. This is why you don’t cut the ferns until they are totally dead.

    You should have your answer in the info I’ve given you. Let me know,

  • Hi Theresa! Wonderful article!
    I am somewhat a city slicker and do not have a great garden space in the backyard as of yet. So, I have a patio garden. I have started just a few asparagus plants and they are shooting up nicely for the first year. In the fall, when we are planning on starting raised beds in the yard (as we have clay soil and peonies will be ready to transplant), is it possible to transplant the asparagus roots from the patio to the beds?
    Thank you!!!!

  • Hi Michelle. Glad to have you reading and glad you are working towards a garden in your backyard space. A Patio garden was a great way to get started.

    I think your asparagus will more than likely do beautifully when you transplant them into the soil — especially if you raised the root from seed and this is it’s first year. But even if the root was already a year old root when you planted it you have a good chance of it doing ok.

    Improved clay soil is excellent in just about every way. Asparagus do not like UNimproved clay soil at all, but they will do fine in improved clay soil.

    It just occurred to me that by raised beds — you might mean that you are going to add purchased soil on top of your clay in frame of some type. (Raised beds in my garden are the result of properly preparing my soil — which was the original meaning of “raised beds” before all the “marketing” got involved. That raises the soil. I have no wooden frames. Just not necessary.)

    If this in fact is what you mean — I don’t know that your asparagus will do well. They like to be in real ground and the roots like to spread in properly prepared soil. (Search my site for how to do that.)

    If you need more clarification — just ask.

  • I am in my second year of full harvest? Some of my spears are coming up twisted, curled or like cork screws. Any thoughts?

  • Hi Phyllis,
    Every year I have at least 3 or 4 asparagus spears come up as you described. I harvest hundreds of spears so I figure 3 or 4 twisted ones are not too bad.
    But if I had all of them coming up twisted and curled I’d be rather upset.

    I’ve read that deformed spears can be caused by asparagus beetles, any damage sustained from cultivation of the soil, and herbicides (even those that blow over from property of a neighbor).

    I would think the twisting and curling can also be caused by the spears working their way through mulch that was a bit too thick. I think my few were caused by that.


  • Hi Theresa,

    Really enjoyed your blog. I have a question….should I thin some of the hundreds of asparagus seedlings that show up between the rows of plants? This is a 3rd year bed that needed some plants replaced because my first planting appeared to be not of the best stock, skinny or no ferns the second year (we did no picking for 3 years).

  • Glad you are enjoying TMG, Monica.
    Asparagus roots like room, so yes, you should thin or take out the volunteers. If you want to use them, move them to another place or use them to replace the old ones that need replacing.

  • I planted nearly 4 years ago a bed of 12 Jersey Knight asparagus plants in a bed I prepared carefully. These plants were a year old when I purchased them.
    I didn’t harvest on the first year, only taking a very small percentage (10%) on the second year and last year I picked for two weeks. Last years harvest was really small, less than pencil sized and the years harvest was perhaps enough for one child’s small portion!
    When I planted in 2011 there had been an awful draught and in my lack of wisdom I thought placing a wickered thin garden mess at the bottom of the trench might mean that the asparagus bed wouldn’t then be in danger of drying out! Since then and on reading up about how these plants hate to have its roots restricted, do you think I should take the bed up and start again? This years shoots are just piercing the earth and on a close inspection they look once again skinny, with many twisted heads.
    Perhaps I need to leave them be and develop patience! Something also needed in the bucket load for growing asparagus!

  • I know it is always disappointing when we put a lot of work into something like a perennial asparagus bed, and then find we’ve done something that was not in the best interest of those plants. We’ve all done that, Debbie, so I know how you feel.

    I definitely would not like the idea of that mesh being in the ground with the asparagus. As you probably know by now, the absolutely best way to hold as much water as possible in the soil is to continually add organic matter to the soil and to mulch the soil.

    Asparagus grow well in soil that is rich with organic matter and that is loamy or even sandy. They don’t particularly care for clay soil unless it has been really improved.

    It appears that you are continuing to get small spears. I don’t know all your details, but it could be the mesh (in part at least) or the lack of organic matter in the soil or clay soil that has not been improved.

    If you feel you need to start from scratch with this additional information under your belt, then go for it. A nice asparagus bed will last a lifetime and give you 6 to 8 weeks of good eating each year.

    Let me know what you decide!
    Good luck!

  • hello Theresa, I planted 150 2 yr old asparagus roots in early june. This is in southern Indiana. I prepped the soil really well with compost horse manure and some rock dust. I planted 3 different varieties, Everything looks great, all the roots are doing excellent. I have not harvested anything from plants other then an occasional pick and eat a single spear.
    My question is this, it’s now into second week of september and the roots are still sending up large spears. By large I would estimate around 1/2 inch in diameter. Is this normal?

  • Sounds like you’re going to have a great asparagus bed Bram. And yes, it’s normal for your asparagus to continue to send up spears as long as the weather holds. Once it turns really cold and the ferns turn brown, they’ll stop growth until spring.
    That’s one big asparagus bed Bram. I assume you plan to sell some of your bounty. Best of luck with it!

  • sounds great and thanks for the reply. Just wasn’t sure what to expect as I have never grown asparagus before.
    I have a small company and we just started growing our own food organically. So I am hoping that most will be consumed in house but I have a feeling I over did it.
    thanks again

  • I’m delighted to hear that you’ve started growing your family food organically. There’s nothing like the taste of organic straight from your own garden.

    And yes, you probably overdid it a bit with the asparagus, but as long as you have that kind of space, I think you’ll be delighted that you have extra. To offer fresh cut organic asparagus to a handful of select customers would be what I would do. I’d have a list — a few more folks than I could supply since there will always be someone who doesn’t come through. In the peak of the season you could supply a lot more. Perhaps a gourmet shop or organic health food store or local grocery would take some.
    Compost or dig in the cut spears that are not used or sold. I’d want to be known for the freshest and the best.
    You can’t go wrong.
    Keep in touch and let me know how you do.
    All my best wishes,

  • I know this post was written a while ago, but I’m still hoping you can offer advice. We love asparagus, and we’re trying to grow it now. I only have enough room for 10 clusters at the moment. Only three have put out spears and they are pencil thin. One of these clusters have 5 growing at once. They are purple passion. I don’t know what’s wrong with the other clusters. Maybe I’m not being patient. The soil is good, so it can’t be that. Maybe I need to return them to Pike.

    Warm Regards,

  • Angel, other than what you told me I don’t know much about your situation so I can only offer general comments.
    1. I don’t know where you are and what your temperatures have been, but I’m in Virginia and 99% of my asparagus has not shown itself yet, which is normal.
    2. The first year the asparagus would be pencil thin.
    3. I’m not sure what you mean by clusters. Asparagus is planted one root ever so many feet.
    4. I’m not familiar with “Pike” but it wouldn’t hurt to call them and ask. Would make you feel more comfortable.
    Hope this helps.

  • Sorry, Theresa!
    1.)In GA where temps have been cooler.
    2.)They are actually thinner than pencils. {I imagined thicker.}
    3.)Planting asparagus is new to me. I did space them appropriately, but their roots look like clusters to me or tiny octopi. I guess that’s why I called them that. Sorry! Didn’t meant to cause confusion.
    4.)Pike is a chain nursery here in GA that sells all kinds of plants.

    Perhaps I need to be more patient. It’s just that not all the roots are putting out asparagus, and I wonder if they may not have taken.

  • Thanks for the clarification Angel. And yes, thinner than pencils is the case many times especially for beginning asparagus.
    If it’s been cool, then patience is what’s needed. If any roots have not put up asparagus by mid May, then it’s possible they may not have “taken”.
    Now I understand why you called the roots clusters. They do indeed look like octopi!
    Let me know what happens and feel free to ask questions whenever you need to.

  • Hi Theresa, I live in Seattle and 3 years ago I planted 3 root clusters of asparagus, almost identically to how you described above. Well soiled, lots of mulch, piled soil on top etc. While I haven’t harvested anything each year I’m only getting around 10 spears. They vary is size – this year a few are really thick (1 1/2 – 2″). I leave them alone mostly, cutting them back only when they turn brown.

    I’m concerned about the thickness – should I go ahead and trim these thick ones down? They’re actually getting ready to leaf up and flower now….

    What can I do to encourage more spear growth?

    Many thanks Theresa!

  • Peter, since your asparagus are now 3 years old, it’s time to start harvesting. When my asparagus start coming up I harvest even the smallest of spears. Cutting the spears is what encourages more spear growth. If you don’t cut, you won’t have as many.

    It’s still early in the season, so why not go ahead and cut even the spears you’ve let develop. Then you should see more replace the ones you cut every day or two or three.

    Since this will be your first year harvesting, I would suggest harvesting for only 4 weeks. Long established bed can sometimes be harvest for 6 to 8 weeks.

    Let me know how you do.

  • This is my 3rd year for my asparagus (northeast 6).Most are pencil lead thick,not all, but most. I hear that sometimes the cause of this is not enough soil over the roots.If this is so, can I put more soil on top of the spears and hope for the best or when should I add more soil,if this is my problem ? Also if I mulch, can I use straw and if so how thick and when should I add ?
    Thank you.

  • Ron, regarding putting more soil over your 3 year old roots, I would feel free to do it anytime I wanted. I use straw for mulch and like to use 6 to 12 inches when I have enough straw. It settles down to much less and in additon it oxidizes over the season and you’ll end up with a thin layer until you replenish.
    Hope this helps.

  • I have an asparagus bed that was planted about 5 years ago. First year I did not harvest, second year harvested a little, and third year quite a bit. All seemed well until last year when i suddenly had fewer stalks and this year still fewer.

    I am thinking of a few things that might be wrong:
    + Hard winters in northeast last two years. This year was cold with no snow cover.
    + Am I not watering or fertilizing enough.
    + Black Walnut tree in the neighboring backyard? (This tree has been there all along, large sized through all the years of asparagus bed so I am not sure that’s it.

    What should I do? I have picked 20 stalks this year so far but have left all the thin ones. Should I stop picking for the rest of the year and apply some plant tone and composted organic matter? We generally do not use manure but instead use our own composted cuttings, grass and leaves from the yard.

    Thanks for your help

  • (Addendum to above. It might actually be 6 or more years. We definitely had a few good years of harvest before the thinning began!

  • Patti, I’m glad for your addendum because that says a lot!

    Just for the record and for others reading — asparagus can — even in the best of beds and conditions — put out the occasional very thin stalk. But overall, a healthy bed should put out a majority of nice-sized stalks, although some (like the female plants) will be a bit smaller than others.

    * Asparagus like cold winters where they will go dormant and gain strength each year. That’s why they don’t do as well in areas where it stays warm all year. Based on that, I’d say your cold winters are not the problem.

    * I don’t how you garden, but if you garden the way I recommend (supplying organic material to your beds every year and keeping the soil covered) there would be no need for you to water (living in the northeast of the US rather than a dessert area) or “fertilize” your asparagus bed. If you garden conventionally, you may want to seek advice from a more “conventional” source.

    * The Black Walnut trees could be the problem. Even other walnut trees are usually grown on Black Walnut stock, so they too put out the same toxin (juglone) into the soil. Some plants are not susceptible to harm from juglone, but asparagus are one of the vegetables that are. And although the tree has been large all the years the bed has been there, it’s roots could now be encroaching on the bed and affecting the asparagus. I would suspect this to be the case since you said you had a few good years of harvest.

    * During my weeks of harvest each year, I cut all the spears no matter how small. It is the cutting of the spears that makes them continue to produce more spears.

    * I had to google “plant tone” Patti. I see now that it’s a fertilizer.
    As I mentioned previously, if you are gardening the way I recommend, “fertilizers” won’t be necessary because the organic material you add to the beds do all the “fertilizing” for you.

    * Compost from your cutiings, grass and leaves are fine to use.
    One note that may or may not apply to your situation: Although it is primarily the roots of the black walnut that put the juglone into the soil, there are smaller amounts in the leaves. The toxin is said to break down when exposed to air, water, and bacteria allowing the effect to degrade in a few weeks or so.

    I can’t tell someone else what they should do since I don’t know all the facts of your situation. But based on only what you have told me, I can share with you what I would do.

    – At this point, I would cut all the stalks that you have allowed to grow. I’d harvest for the remainder of your season of harvest.

    – I would suspect the black walnut tree roots and start digging around to see if they go into the asparagus bed. If they do — I would try to get them out and plan a strategy to keep them out each year and at least 4 feet or more from the bed. (The distance I gave is just a gut feeling guess. Info from the university of Wisconsin advises planting susceptible vegetables 50 to 80 feet from the trunk of any walnut tree.)

    – If you feel that you will be unable to keep the roots out start thinking about where you could place a new bed. (Even if the roots are not toxic, asparagus do NOT like competition and will decline if roots are allowed to grow into them.)

    Hope this has been of help to you, Patti.
    Something like this can be really upsetting. I had a beautiful asparagus bed that gave me the most gorgeous spears for years and it was ruined by some “horror-story” invasive trees that were allowed to grow on a neighboring property. I was so upset about it I couldn’t even talk about it for 3 years. My ferns use to be so large they looked like trees and now they’ve been reduced to whisps.

    I’m in the process of establishing asparagus in others areas of our property. Not easy, for various reasons, but it’s my only choice.

    Let me know how you do.

  • Theresa, first thank you for helping everyone. You state that you must leave the stalks go to ferns so as to let the sun do it’s work. My problem is that I don’t know when to start leaving the stalks go to ferns or how many. This is my 3rd year for the plants and a lot are very skinny. I am in zone 6 in northeast Pa.. It is now May. Thank you.

  • This last spring I bought and planted a new hybrid asparagus called ” Asparabest” . I dug trenches and carefully planted them. I planted 20 of them and all of them came up and were doing very nicely here in VA. The ferns are lovlely now, but I’ve seen a couple stalks that were starting to fern-up when the tiny branch tips turned brown, and went limp. I dont see any rust color. Ive checked daily for beetles and only seen one. I have carrots, onions, tomatoes and zucchini in the backyard. Should I remove these sickly stalks or just ignore them?

  • I would keep a close eye on things Nancy and look for asparagus beetle larvae. They’re tiny – sometimes 1/4 inch long and like
    a little worm-like.
    When asparagus beetle larvae feed on the ferns they’ll “defoliate” the branches and they’ll turn brown.

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