Preparing asparagus for winter

I have five long asparagus beds located in the back of my flower cutting garden. My gardening crew has already started to secure twine along the sides of the bed, so they can be reshaped.
Chhewang places the twine stake on one end of the bed. Remember this twine holder and stake set from my old collection at Kmart? These still work perfectly after many years.
And then using short sections of bamboo, the twine is guided alongside the entire perimeter of the bed.
Here is an asparagus stalk in spring, when it’s ready to be picked from the garden. Asparagus, Asparagus officinalis, is a spring vegetable, a flowering perennial plant species in the genus Asparagus. Asparagus crowns can produce tasty spears for 20-years or more if given the right care and nutrients.
While green and white asparagus are the same, purple asparagus is a different variety. This variety was originally developed in the Albenga region of Italy. The purple hue is only cosmetic, as the pulp of the vegetable remains green or even white.
Before the the mulch is put down, Ryan sprinkles some plant food on all the beds. I love my new All-Purpose Plant Food from QVC. It’s great for all types of plants: flowers, vegetables, trees, and shrubs.
My plant food is formulated to boost initial plant growth, help roots thrive, and protect against transfer loss. It contains a blend of microbes, mycorrhizae and other nutrients that break down gradually to provide a safe, long-lasting food reservoir throughout the growing season.
The bag is also resealable, so any leftover food can be safely stored. Here, Ryan sprinkles fertilizer on the last two asparagus beds.
The next step is to cover the beds with composted mulch. Carlos places a generous amount in clumps along each bed.
As you all know, we make all our compost right here at the farm. My compost piles include this dark organic matter made up of manure and biodegradable materials. Compost is ready to use after two-years. During this time, it is mixed with water, oxygen, carbon, and nitrogen, which break down the organic matter and eliminate odors.
For asparagus, it’s ideal to cover the beds with about four to six inches of mulch over the crowns.
Here are the asparagus stalks once they are covered with compost – the crowns underneath are now well protected.
The cut fern stubs help hold the mulch over the crowns, providing a good insulating layer against the winter cold.
Chhewang carefully levels the mulch over the bed with a hard rake. Prepping asparagus beds for winter will protect the roots from the cold and encourage the plants to go dormant, allowing the plant to rest before its next growth phase in the spring.
He also uses a spade to create narrow footpaths in between the beds.
Chhewang then uses a soft rake to make it neat and tidy. Healthy and robust crowns are really the key to growing asparagus. By next growing season, nutrients from the manure will have leached-in and amended the soil.
Autumn is also a good time to check the soil pH in asparagus beds. Asparagus plants prefer a sweet soil—a pH of at least 7.0. To adjust the pH, add lime to raise it, or sulfur to lower it.

Here, Chhewang does the same to the two beds on the other side of the garden. Each year the bed does get a little more raised, but that’s a good thing. It makes for better drainage which is important for the asparagus roots.
Chhewang also spreads a layer of composted mulch on the rhubarb bed. A two to three inch layer will prevent winter winds from drying out the roots.
As long as the soil is well drained, the crowns will survive even hard freezes with a layer of mulch. Rhubarb is a species of plant in the family Polygonaceae. It is a herbaceous perennial growing from short, thick rhizomes. The fleshy, edible stalks, are used in cooking, but the large, triangular leaves contain high levels of oxalic acid, making them inedible.
All the beds look great and ready for the cold season ahead.
With just a little proper care in the fall, we’ll have many juicy green and purple spears in spring as well as rhubarb. How do you care for your asparagus and rhubarb plants? Share your winterizing plant tips with me in the comments section below.

Cooperative Extension: Garden & Yard

Frequently Asked Questions for Asparagus


If I can’t plant my asparagus right away, how do I store them?
Place your plants in your refrigerator. Do not allow the roots to dry out. Plant them as soon as possible.

Should I put fertilizer (granular or otherwise) in the hole at planting time?
All fertilizer should be mixed thoroughly into the soil prior to digging the hole and planting. Fertilizer can burn tender roots if they touch directly.

How close should I plant these crowns?
Allow 12” to 14” between crowns and four feet between rows. Resist the temptation to place the crowns too closely. Good light and air circulation from wide spacing promotes growth.


Does it matter what kind of mulch I use at the base of the plant?
Yes. Mulch should be loose enough for water percolation. Straw, pine needles, pine shavings or bark mulch work well as mulch choices. Avoid using dyed mulches (black or red). Avoid using synthetic mulches like black plastic or landscape fabric.

How thick should I spread the mulch?
Spread the mulch 4 inches thick around the newly emerged spears.

May I just let grass grow around the base of the plant as a living mulch?
No, grass will compete for nutrients and moisture. Asparagus perform best with clean cultivated bare soil.


How often should I water my new plants?
Provide 1 inch of water per week.


What pests might be attracted to my asparagus?
You may find asparagus beetles, Japanese beetles and cut worms. Don’t panic, plants can endure some insect feeding without seeing any harm to next year’s crop.


When can I plan to harvest my first asparagus from this planting?
Spears can be harvested next year as a very light harvest (one meal). Waiting two years would be better. By not harvesting in a heavy way, you are allowing the crowns to be more productive over the life of the planting.


Are the asparagus plants that I received from this project guaranteed?
No, these plants are not guaranteed. However, we believe we have provided all the information you will need for successful growth.

How long do asparagus typically live?
With proper care and in the right environment, asparagus live 7 years or more.

What care do I provide for my asparagus in preparation for winter?
After the fronds turn brown, remove them by cutting them off at the base. You then have the choice of leaving the bed bare for the winter and hoping for good snow cover to protect the crowns, or mulching the bed with 4″ – 6″ of straw, shavings, or sawdust. A covering will protect the crowns from heaving and cracking if we get an early spring thaw followed by more freezing temperatures.

The disadvantage of having a mulch on the bed is that it will slow down the emergence of the spears next spring. They will grow right through the mulch, and the mulch will help keep weed growth down. Once all danger of frost is past in the spring, you could rake the mulch off to the side, which will allow the soil to warm up faster and the spears to emerge sooner.

On the Farm

Growing asparagus isn’t especially difficult, but it has that reputation. Yes, it’s a little tricky to plant at first. Yes it requires fertile, well-drained soil. Yes it takes a few years to get a decent harvest. However once established, I’ve found asparagus to be relatively low-maintenance, and a true garden favorite. There are a couple key practices to remember though when you put your bed to bed for the winter.
Like its cousins the onions, Asparagus officinalis is a member of the Liliaceae or lily family. It’s been cultivated since ancient times. Asparagus is a dioecious, which means there are distinct male and female plants. In recent decades, the all-male hybrid varieties from New Jersey (like the “Jersey Giant”) have become very popular. Male plants produce a greater number of spears, and no berries which eventually germinate and become like hard-to-pull weeds. Asparagus does not compete well with weeds. Weeding the bed is generally by hand because any deep cultivation can damage the asparagus. Neglected, weedy beds do very poorly. Asparagus plants have three parts, the top (fern), the crown (just under the surface where the buds form), and the roots (below the crown). The fern creates energy which is stored in the crown. The more energy and nutrition stored in the crown during the summer and fall, the more spears in the spring.

Asparagus ferns ready to cut back for the winter
That’s why it is important not to cut back the ferns until November when they’ve completely browned and lost all viability. In fact, it is always the last act of my gardening season. I like to cut the the ferns a few inches above the surface, pull any weeds, and then cover the bed with a good 6 inches of lightweight mulch. I use composted wood shavings from the chicken coop. It is excellent fertilizer and not too heavy. The cut fern stubs help hold the mulch over the crowns, providing a good insulating layer against the winter cold. Healthy and robust crowns are really the key to growing asparagus. By next growing season, nutrients from the manure will have leached-in, and the thick layer of shavings will be mostly composted and reduced. Each year the bed does get a little more raised, but that’s a good thing. It makes for better drainage which is important for the asparagus roots.

Leave a good six inches of stem to hold the mulch and create air space.

A well-maintained asparagus bed will be productive for 20 years or more. There aren’t too many cultivated plants which can claim that. With just a little proper care in the fall, you will be rewarded by many juicy green spears when spring comes around. Asparagus can be that easy.

There are a couple of things that should be done to winterize your asparagus patch. In the late fall or early winter you should cut back your asparagus ferns. This will help to break the pest cycle of the asparagus beetle that loves to overwinter in the ferns. Wait until the leaves are yellow and brown. Then cut them down with good sharp pruners. Make sure to leave about 2 inches of the asparagus plant above the surface. If you cut them too low, that can cause damage to the crown, or growing point. After you have cut them back add about 4 inches of mulch to protect the roots from any winter damage. Finally, make sure you put the cut ferns far away from your asparagus patch. A compost pile is a good spot. I put them in a far corner of the garden and let the chickens peck at them. They like to pick at the berries and seeds, and they love to walk and sit on the soft ferns.

Asparagus ferns ready to be cut

Asparagus cut, make sure to leave 2″ above the ground

Then add 3-4″ of mulch for winter protection of the roots

~ Phil Williams

Phil Williams is a permaculture consultant and designer and creator of the website His website provides useful, timely information for the experienced or beginning gardener, landscaper, or permaculturalist. Phil’s personal goals are to build soil, restore and regenerate degraded landscapes, grow and raise an abundance of healthy food of great variety, design and install resilient permaculture gardens in the most efficient manner possible, and teach others along the way.

How to Prepare Asparagus Plants for the Winter

As one of the first spring vegetables in the home garden, asparagus provides tender green shoots for eating in the spring and airy fern-like foliage throughout the summer making it both practical and ornamental for the home garden. Grown in full sun, asparagus prefers a pH of 6.5 to 7.5 and requires well-drained soil. Applying a balanced fertilizer (10-10-10) in early spring for the first three to four years produces tender young shoots. Later years benefit from fertilizer applied after harvest. Asparagus requires minimal care (once established) and returns each spring with larger stalks.

Cut yellow or dying foliage back to ground level in late fall to prevent disease or insect pests from over-wintering on the plants.

Rake the area free of plant debris and weeds. Handpick any weeds around the base of plants and discard.

Cover asparagus crowns with 3 to 4 inches of organic mulch in late fall. Use hay, straw or leaves to form an insulating layer to provide protection from thawing and freezing during winter months.

Remove mulch in spring before shoots appear.

By fertilizing, you can make your asparagus bed produce better than it ever has.

On established beds, you should split the fertilizer application. Put one-half the amount on the bed before the asparagus comes up. Till the fertilizer into the soil.

It’s important to work the soil early before it dries out and becomes too hard. Warning: don’t work the soil while it is too wet because the soil will pack.

Now is also a good time to remove some of the perennial weeds. This will make cultivation easier later in the season.

After you’ve finished cutting your asparagus crop, apply the second half of your fertilizer. This will help build up your 1996 asparagus cuttings. This year’s roots will store plant food for next year’s crop.

You may wonder just how much fertilizer to use. Plan to apply two and one-half pounds per hundred square feet. Or by the row, put on one-half pound for each hundred-foot row. Use regular garden fertilizer, 5-10-5 or 5-10-10.

If your asparagus bed is several years old, have the soil tested. This will be helpful in determining what rate and grade of fertilizer to use.

And here’s how to simplify weed control in your asparagus bed: Use a loose mulch. Good mulching materials include sawdust, wood chips, shavings and ground corncobs. These materials shut out weed growth, but still permit asparagus to come up.

Caution: if applied too early, it may tend to keep the soil cool. This would delay your harvest of asparagus, but that doesn’t hurt it.

Another frequently asked question is: “Can I let my asparagus go this season without cutting at all?”

The answer is yes, you may, if you fertilize and keep weeds under control. In fact, this actually would do the plants some good. Reserve food supplies would be built up in the roots. And this would make them stronger for the next few years.

And a final warning about weeds in the asparagus bed. If you neglect weed control for a year or two, weeds will become a serious nuisance, and later weed control will be difficult.

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There are plenty of reasons why you should lime your garden if it needs it. Most vegetables grow best on slightly acid soils.

Liming reduces acidity. But it isn’t acidity in itself that harms plant growth. Actually it’s the chemical reactions in the soil that are made possible by acidity that affects the plants. Lime stimulates decay — provides better environment for bacteria activity. Plant food is released through decomposition of organic matter in soil.

Lime greatly influences availability of fertilizer you apply. This is not possible on sour soils.

Acidity of a soil is expressed in terms of pH. That’s the standard measurement of soil acidity. If soil has pH of 7.0, it is neutral. Below 7.0 soil is acid.

A pH of 6.2 to 6.8, or slightly acid, is best for growing most garden vegetables. If pH is below 6.2 a lime application is recommended. If pH is below 6.0, soil is considered very acid. If pH is 5.0-5.5, lime is absolutely needed. You apply lime here to get the most from the fertilizer you put on.

If pH is 7.0 or above, the soil is considered alkaline.

As soil alkalinity increased, we get similar results as when it becomes acid. Some of the fertilizer materials may become unavailable. We have some soils with pH 8.0 and still grow good crops. These are located around cement plants.

It’s a gradual buildup over a period of years, consequently not a problem. However, with a pH of 8.0 brought on by a heavy lime application, you sometimes experience plant growth problems.

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Don’t fail to plant some peppers in this year’s garden. Peppers are a great standby crop and mix well with most meals. You’ll find may good pepper varieties on the market.

California Wonder is a variety heavily used. Set out your peppers plants about twenty-four inches apart in the row. Time of planting is about the same as for tomatoes. Remember, peppers are frost-sensitive, so don’t set out too early.

Be careful not to put too much nitrogen fertilizer on peppers. Put on perhaps 25 pounds 5-10-10 fertilizer per thousand square feet.

Some folks have difficulty in getting peppers to set fruit. One reason is hot weather –blossoms fall off without setting fruit.

Another reason is fertility is too high — plants go to leaves. If soil is fertile, space plants closer together. This will make them compete with each other, more likely to set fruit.

There is no reason why you shouldn’t set out a few eggplants too. Handle the crop through the season about the way you do peppers. Some folks think eggplant is harder to grow than peppers. There may be more danger from disease, but in general they are hardy.

Just a few plants will provide plenty of eggplant for the family. Remember, young eggplants are frost susceptible, so don’t plant too early.

With peppers and eggplant, as with all other garden crops, keep weeds down while they’re still small. Protect against weeds, and conserve soil moisture with mulch.

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PHOTO: Julie Faulk/Flickr by Erica Strauss March 17, 2014

I‘ll never forget the flavor of the first fat spear of asparagus I snapped from my own garden. It was sweet and juicy, and it snapped under my teeth with only the slightest hint of that sulfurous, grassy flavor that you often find in store-bought asparagus. I had planted 10 crowns three years before in a wide mound of sandy soil in full sun. The asparagus thrived, and my education in growing this long-lived perennial delicacy began.

Asparagus is a fairly unique vegetable because in a healthy mature patch, you harvest first and grow later. The edible portion of asparagus is the spear, which pushes up through the soil from a deep, energy-storing root system. This spear wants to become a tall, billowy frond that captures sunlight to send back down to the root system, but you’ll pick spears young, before they have a chance to toughen and unfurl.

To cultivate a healthy crop, pay particular attention to the soil in your asparagus bed. Asparagus is deep-rooted and prefers sandy, well-drained soil—areas that stay wet will rot the roots and invite disease. Here are some additional tips for prepping and maintaining the dirt your asparagus calls home.

1. Load Up on Phosphorus
Asparagus loves phosphorus. Composted manure, bone meal and rock phosphate are all good amendments to keep soil levels high in this nutrient.

2. Hold the Salt
While asparagus is salt-tolerant and grows well as a perennial in seaside gardens, the occasionally recommended advice to add salt to an asparagus bed isn’t wise and can seriously damage soil quality.

3. Don’t Rotate Beds
When happy, asparagus settles in for the long haul. It can live and produce for two decades or more, but it loathes having its roots disturbed for any reason, especially moving. Pick a location where your asparagus can literally put down roots, and avoid digging or deeply cultivating the soil around your asparagus patch.

4. Keep It Weed-Free
Because asparagus is so long-lived, it’s especially important to rid your planting area of any pernicious perennial weeds. Invasive creepers, such as bermuda grass, bindweed, quack-grass and buttercup, are difficult to eradicate, but they’ll out-compete your asparagus stand and must be removed from the soil before planting. Monitor the asparagus patch seasonally to keep weeds at bay.

5. Top-Dress Every Spring
Keep your asparagus patch performing well by top-dressing every spring with 2 to 3 inches of composted manure, followed by a 2-inch layer of loose organic mulch. Shredded arborist’s woodchips, straw and finished compost are all good choices. This top-dressing will provide the soil with nitrogen and phosphorus, as well as keep it weed-free and in good tilth.

6. Fertilize Twice A Year
Asparagus is a relatively heavy feeder. While the spring top-dressing will feed and add organic matter to the asparagus patch, you’ll get even better results if you feed lightly in early spring and again in mid-summer with a high-phosphorus organic fertilizer, like fish meal, which has a typical N-P-K value of 8-12-2.

7. Minimize Disease and Pest Risk
A patch of asparagus grown in well-drained soil is rarely bothered by disease, but fusarium wilt, purple spot, needle blight and asparagus rust can all infect your crop. If these diseases are known to be an issue in your growing region, planting resistant cultivars is essential. Your local extension program will know what issues tend to crop up in your area. For asparagus growers everywhere, siting asparagus in an area with good airflow and practicing good sanitation is important to discourage pathogen and disease build-up in the soil. At the end of the growing year, cut down and hot compost or burn the fronds and clean up debris.

Asparagus’ most common pest is the asparagus beetle, which will often overwinter in the soil. Good sanitation and allowing hens access to forage for the beetle can help reduce a buildup of these pests.

8. Companion Plant and Cover Crop
Asparagus enjoys being planted alongside other perennials, like rhubarb and fruiting shrubs, but avoid planting companions too close to minimize competition. The fronds of mature asparagus can reach 5 feet or taller, making this plant a great option for the middle layer of a stacked perennial bed. To build soil fertility naturally, an established asparagus patch can be under-seeded with a low-growing, nitrogen-fixer cover crop, like crimson clover, and interplanted with phosphorus bio-accumulators, like yarrow. In some areas, both crimson clover and yarrow can be invasive, so select the right soil-improving bio-accumulators for your region.

9. Start Out Right
Asparagus can be started from seeds or crowns—the crowns offering beginners a one- to two-year headstart on a harvest and often an ideal choice for beginning asparagus growers. However, if you want to start your asparagus from seed, sow it directly into well-drained, loose, fertile soil in a well-weeded, prepared bed after the soil has warmed enough to initiate germination—typically in April or May. Soak seeds in cool water or dilute compost tea for 1 hour before sowing, then space 8 to 12 inches apart. Cover seeds with 1 to 2 inches of loose, sandy soil and thin to an eventual spacing of 12 to 16 inches between plants. Keep soil moist until germination.

Alternatively, start indoors in late winter. Soak seeds in cool water or dilute compost tea for an hour, then sow seeds 1 inch deep in 4-inch pots filled with an organic potting mix that includes an organic, slow-release, balanced fertilizer (3-3-3 or 5-5-5). Keep the soil warm, and as soon as seeds germinate, set pots under full-spectrum grow lights or in a bright, sunny window or greenhouse, depending on outdoor temperatures. Transplant to the garden in mid to late spring when soil has warmed.

If you opt to plant crowns, keep in mind asparagus suffers some transplant. Plant crowns as soon after purchase as possible, in a prepared bed of well-drained, sandy soil. Dig a shallow, 6-inch-deep trench 12 to 18 inches wide and soak crowns for 15 minutes in cool water or diluted compost tea. Place the crowns 12 to 18 inches apart along the trench, spreading the roots out gently. Top with 2 to 3 inches of loose soil. When the shoots begin to appear (in several weeks to a month or more, depending on soil temperature), hill up around the growing crowns with another inch of soil. As the shoot grows, continue adding loose, sandy soil to the trench until it is filled.

Given the right early attention, asparagus is an investment that can really pay off. The first few years will require the right soil prep and a little babying to make sure the crop growing well, but after it’s established it’s a low-work culinary prize for the gourmet gardener.

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