Protect perennial asparagus plants from cold temperature damage by mulching the asparagus bed with compost, aged manure, or straw before freezing weather or snow arrives.
Asparagus crowns can produce tasty spears for 20 years or longer if given the right care and nutrients.
The ferny stalks and branching growth of asparagus plants capture energy through photosynthesis during the growing season strengthening asparagus crowns (the collection of fleshy roots just below the soil surface) for spear production the following year.
Leave asparagus stems on plants as long as they remain green—well into autumn. When stalks turn brown and brittle cut them off at ground level and top dress the bed with compost or manure. (Place cut stalks and ferns in the trash—not in the compost pile; asparagus-beetle eggs can overwinter in cut stalks.)
Again, cutting stalks back too soon means sacrificing photosynthesis and will mean less spear production next year. The exception: cut down female asparagus plants before they set seed (red berries); seed production diverts energy from crowns and lowers future yield. (Picking off berries is a solution, but highly time consuming. Growing only male plants may be the best course—as well as the source of thicker spears.)
Where heavy snow covers asparagus beds in the winter let stalks turn brown and fall across the planting bed to form their own mulch to protect plant crowns. Then add 6-inches of straw, pine needles, or well-rotted or chopped leaves to the top of fallen stalks to give crowns extra protection from freezing temperatures.
A planting bed of well-drained garden loam is the best home for asparagus plants. Adding organic matter—well-aged compost or well-aged manure and a layer of straw or chopped leaves—to the asparagus bed each autumn will ensure crowns and plants have the nutrients they need to produce ample spears for years and years.
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. Add lime to raise the pH or sulfur to lower it.
Hi! I have a really stupid question. My husband and I just put up a cheap and simple greenhouse over my raised garden with pvc pipe and clear tarp. He insisted on closing of the whole thing (stapling the tarp down on the ends) for the winter. I am worried because my asparagus plants are in there and they are not going to get any water. I hate to tear open the ends of the greenhouse but they need watered even over the winter right????
Thanks for any advice!! Tracy
It would be best to allow some access to your greenhouse through the winter. You can do this by not sealing one end of the greenhouse or tunnel, instead clip it shut. Your plants may need some water, and, as well, you will want to allow for some ventilation should you have a warm spell and temperatures inside the greenhouse start to climb.
Can I plant asparagus now in North Louisiana? I bought crowns at a Walmart 2 months ago. We have a bed with appropriate rows and spacing We have some crowns that we had in s container got years and now I have 2 rows of older plants and we are lettin them fern. Can we harvest them since they are older transplants.
Yes, you should go ahead and put the asparagus crowns in the ground–before they dry out and lose their vitality. Keep the soil evenly moist once you put the crowns in the ground. Your older plants should be at the harvestable stage at about 3 years of age.
I am completely renovating my garden and stating new next spring but I don’t want to lose my asparagus. Can I overwinter them in pots? If so, why would be the best place to store them?
If possible, the best time to transplant or relocate asparagus plants is late winter or early spring while the plants are dormant. If you must move them sooner, take up as much of the plant and root as you can and set it outdoors where it does not get full afternoon son–to avoid too much transplant shock. Overwinter them close to their current home.
My as asparagus is already planted in a pot. Is it OK to take it inside or in a garage for the winter?
If the foliage has died back for the winter, then go ahead and bring your asparagus indoors. If not, let it continue to store energy for production of new spears next spring–until the top dies back.
Can I put manure on my asparagus plants in December? I live in NY
Yes if the manure is well aged. It would also benefit your growing bed to add aged compost. The winter rains and late snow melt will carry the nutrients deep into the soil before the asparagus emerge in spring.
This past asparagus season I did not have much of an asparagus yield. Everything looked okay…a lot of greens…just not enough asparagus. My soil may have been depleted of nutrients. I just cut down the greens this week. I have some bagged soil–a combination of compost/moss…and something else I can’t think of…and some leaves. Would this be enough to put on top for the winter or should I add some other nutrients. This asparagus plot is about 10 years old and I’m in Western PA. Thanks!
It’s best to feed your asparagus bed every year–about this time. Put down 2 inches of aged compost or a commercial organic planting mix.
If you want to give the bed an extra boost, sprinkle 5-10-10 organic fertilizer over the bed before you put down the compost. If it has already snowed where you are, put down the aged compost or planting mix as soon as the snow melts. Let winter snow and rain work the amendment into the soil–no need for you to turn it under.
My asparagus plants are growing over 10-12 feet tall. Should I cut them back or just let them grow for better production? I live in North. Louisiana
In mild winter regions, cut down ferny asparagus top growth after it has turned brown in late fall. In cold winter regions leave top growth to provide winter protection. Top growth will help plants store energy for new production; once plants flower and set red berries, plants will begin to draw on stored energy.
Winters here reach -30c(-22 Fahrenheit), is it still possible to winterize my first year asparagus outside,even with good bedding? Would it be a good idea to bring them inside for the winter?
Once you trim back the browning fronds, you can sprinkle aged compost and aged manure over the bed to feed the roots for next season. Once the first freeze comes, heap more compost over the bed and then a layer of straw to insulate the roots from freezing. If the soil freezes where you live you can lift the roots and store them in peat moss or loose soil through the winter and replant them next spring.
Thank you for all the helpful info. It answered all of my questions.
I didn’t cut my asparagus plants down last winter. I let them fall over and lay over the top. Now that it’s spring, how short should I cut them before adding new mulch and compost?
Cut asparagus top growth down to soil level. You can then sprinkle balanced organic fertilizers such as 10-10-10 across the bed before you add new mulch and compost.
I started my asparagus seeds 10 weeks before Frost ended this year in pots I’ve transplanted 3 *. And then I wasn’t able to get them planted in the ground. Are they going to be okay in there pots till until spring. They’re big bushy and green still. And shall I bring him in the garage four winner where in zone 6A.
Because the asparagus is still in pots it may be a bit late to set them in the garden and expect the roots to establish themselves before winter cold hits. You could transplant them and protect the top growth with floating row covers giving the roots a couple of months to get established. Perhaps a better strategy is to bring them into the garage when the tops die back and then transplant them into the garden in spring.
I started a new bed this spring and was able to enjoy a couple of snacks from it. There are a couple of thin spots where they didn’t take. I’m in memphis tn, when would be the best time to add a few crowns to fill in?
Plant asparagus 4 to 6 weeks before your area’s average last frost date in spring. Asparagus prefers climates where winters are cold enough to freeze the top few inches of soil and provide it with the necessary period of dormancy. In mild winter regions, some folks will dump a bucket of ice over the roots of each plant in winter to simulate the freeze.
This is my first year with Asparagus plants they are looking good , but I was wondering what do I need to do to get them ready for the winter.
I live in Mississippi, and then for the spring time also.
Ruth
Remove the ferny tops of the asparagus plant in late fall at the first sign of frost. After the ferny tops are removed, apply 6 to 8 inches of aged manure or compost over the bed; this will act as a winter blanket and add nutrients to the soil for renewed spring growth. In spring, you will simply wait for new spear growth. If your plants were just started from crowns or seedlings this year they do not harvest the spears for the first two full seasons. Give the plants two full years to establish their roots. The first harvest will come the third year after planting–then harvest for just two weeks. The next season harvest for four weeks.
It is already late October and my asparagus tops are green. Do I cut them even though they are not brown or yellow? I live in zone 7b, Texas.
Hold off cutting back the asparagus tops until they have been hit by a couple of frosts or a freeze. While they are still green they are storing energy for next springs spears.
can I use left over alfalfa instead of straw to cover my asparagus for winter
Yes, chop the alfalfa into bits and spread it across the asparagus bed as a winter mulch (much like you would do with fallen autumn leaves). If you leave the alfalfa unchopped, you will want to pull it back from the asparagus bed next spring. Chopped alfalfa will decompose more quickly adding nutrients to the soil and feed beneficial soil microorganisms. It will also enhance soil composition.
I live in North central CT, my asparagus bed is going the 4th year. I have spaces between sprouts. How can I fill the the gaps? Should I use sets or seeds and how deep should it be planted.
The quickest way to fill in the spaces in your asparagus bed would be planting two- or three-year-old crowns. Crowns will likely be available again early next spring; check with the nearby garden center. Choose crowns that have plump fleshy roots; avoid crowns that look dry. When the soil is workable in spring amend each planting hole with aged compost or commercial organic planting mix and sprinkle bone meal at the bottom of the hole. Soak the crowns in compost tea or a starter solution for a few hours before planting; moisten the planting hole as well. Set the crowns about 6 inches deep (8 inches if the soil is sandy). Plant the crowns 2 to 4 weeks before the last average frost date.