What Happens if You Don’t Cut Your Asparagus Plants?

Ever wondered what would happen to your asparagus bed if you simply left it alone for a while? Would your asparagus plants continue to thrive, or would they perish under the force of the elements? Here’s what happens if you don’t cut your asparagus plants. 

If you don’t cut your asparagus plants, the asparagus spears will deteriorate in quality and taste, gradually go bad, and eventually become inedible. Increased seed production will lead to overcrowding in the future, and excessive foliage growth can increase the likelihood of a sudden infection. 

Leaving your asparagus bed unattended during the harvesting season is not a good idea. In this article, I’ll tell you everything you need to know about harvesting your asparagus spears and cutting down the plant’s foliage, along with the best times to do so. 

The Dangers of Not Harvesting Asparagus

Asparagus plants produce spears during their growing period between early spring and late summer. These spears emerge from the ground sometime in spring and grow in the coming weeks and months. 

Not harvesting the spears has undesirable consequences, which I’ll get into below. 

Before proceeding, I should inform you that asparagus plants aged 1 and 2 are an exception since it’s best not to harvest spears at those ages. I’ll explain why below. 

Your Asparagus Spears Won’t Taste As Good

First, and perhaps most simply, your asparagus spears won’t taste as good if you delay their harvest time. 

After emerging from the ground, an asparagus spear typically takes under a week to reach its adult size. You should harvest the spear immediately after it gets to adult size since it’s at its very best in taste, texture, and freshness. 

Once asparagus spears are fully grown in size, they begin readying themselves to grow ferns. They get tougher and develop a woody, fibrous texture to support the weight of the upcoming growth, which reduces their palatability. 

You want to harvest your asparagus spears before they harden up so you can enjoy them at their best. 

Asparagus spears that are left unharvested and grow ferns are still safe to eat, but they’ll be hard and chewy at the ends, and they will need some trimming around the edges to be edible. Even so, they probably won’t taste very good. 

Your Total Harvest for the Season Will Suffer

Another reason to harvest spears right when they finish growth is to end up with a greater total harvest for the season. 

Spears only grow for a limited time, and whether you’re growing asparagus plants for commercial or domestic purposes, you’ll likely want to harvest as many as possible when you can. 

The best way to maximize your harvest is to keep harvesting spears as they mature so that new ones can start growing in their place immediately. 

Your Asparagus Spears Will Grow Ferns and Bear More Seeds

If you don’t harvest your asparagus spears, they’ll grow fern-like foliage. These ferns will bear what seem to be red berries but are actually seed pods in disguise, each containing several seeds. 

Seed bearing is generally undesirable among asparagus growers since it directs energy away from spear growth and other important processes. 

If you already have an organized, well-established asparagus bed, you probably don’t want more plants to emerge randomly.

If you let nature run its course, the seeds will disperse all over your asparagus bed and perhaps even the rest of your garden. 

While this may not be an immediate problem, it will likely trouble you in the future. After a few years, once the seeds develop into mature asparagus plants, you’ll have to deal with a serious case of overcrowding

Asparagus plants don’t do very well when they have to compete with each other for nutrients. Their health declines, and so do the quality and quantity of their spears. 

By harvesting your asparagus spears on time, your plants will dedicate more of their energy to producing a new spear rather than bearing seeds. 

It’s only the female plants that bear seeds. If you have an all-male variety, overcrowding due to excessive seed dispersal will likely not be as much of a problem. This is one of the reasons all-male varieties of asparagus have seen such rising popularity lately. 

You’ll still need to exercise caution if you have a male-dominated variety (many males and a few females). A single female plant can bear numerous berries/seed pods, each containing as many as five seeds. 

Still, even if you do harvest your asparagus spears on time, some fruit production and seed-bearing after the harvesting season are inevitable. To curtail unwanted seed production, you can pluck off visible seed pods by hand and store them for later use. 

For example, you could use the seed pods to start a second asparagus bed in a controlled manner. 

However, since you can grow asparagus from scraps and spears, having seeds is not an absolute necessity.

Your Asparagus Plants Could Get Infected

By not harvesting your spears on time, you might inadvertently increase the odds of your asparagus plants getting infected by a disease or attacked by pests

You need to keep the growth of your asparagus plants in check. Letting too many spears grow ferny foliage will create a cover for pests and insects that want to snack on your asparagus. 

The asparagus beetle is a particularly bothersome pest that tends to infest plants that don’t receive regular maintenance, especially in the harvesting season. 

When Should You Harvest Your Asparagus Spears?

Given that it’s best to harvest these veggies in a timely manner, what is the best time to harvest them?

Spears begin their growth relatively early. They typically begin showing signs of growth right when the last of the winter frost ends. You can expect to see spears well on their way to being mature in the early spring. 

In certain areas, spears can start growing in mid-to-late winter. This presents a problem if the last winter frost has not yet passed, as it will likely kill the budding spears or at least hurt them significantly. 

If you live in such a region, it’s best to harvest whatever spear growth there is before the frost hits. 

In regular conditions, it’s best to harvest the spears when they’re 6 to 8 inches (15.24 to 20.32 cm) in height. This is a general guideline, and you don’t have to follow it precisely. Some more relaxed gardeners agree on 5 to 10 inches (12.7 to 25.4 cm) as the acceptable limit. 

The important part is to harvest your spears when it seems like their growth has slowed—and you’ll be able to tell. 

You see, asparagus spears grow incredibly quickly in spring. They can grow as much as two inches (5.08 cm) every day, which means a spear will go from barely noticeable to full-sized and ready for harvest in a few days. 

So when yours don’t grow noticeably over a day or two, you’ll know they’re ready.

Harvesting regularly will help you fully reap the fruits (or, in this case, veggies) of your labor. 

Lastly, you should know that the harvesting season lasts only around 2 months. After 8 weeks have elapsed from your first harvest, you should stop any further harvesting. 

Spears will continue to grow, but at this point, you need to let them develop into ferns. I’ll explain why in a bit. 

What if You Harvest Your Asparagus Spears Too Early?

We already know that harvesting too late gives us poor-tasting crops, and not harvesting at all leads to problems like overseeding and pest infestations. 

What about harvesting too early? Is it also just as much of a problem?

Fortunately, the answer here is no. Harvesting fully grown – 6-8 inches(15.24-20.32 cm) – asparagus spears is still best, but early harvesting won’t hurt. 

You’ll get a shorter, thinner Asparagus spear (which equates to fewer servings per spear), but the next spear to be harvested will also begin its growth sooner.

In the end, you may be able to harvest more spears overall by potentially getting in an extra harvest, which somewhat makes up for the thinner spears from your first harvest. 

Keep in mind that this is still suboptimal. Even if you’re okay with harvesting more spears at the expense of their size and thickness, I wouldn’t recommend harvesting a spear until it’s at least 5 inches (12.7 cm) in height. 

Also, consider that thin spears often can’t compete with thicker ones when it comes to nutritional value. If you intend to make asparagus a routine part of your diet for health benefits, give the spears time to grow fully before harvesting. 

On the other hand, commercial growers may find the quantity-to-size tradeoff more favorable. 

It’s Best Not To Harvest Spears in the First Two Years

This may be disappointing news, but if you’ve set up your asparagus bed only recently, you may have to hold off on harvesting any spears for the first two growing seasons. 

You probably already know this, but spears are the stems of asparagus plants. The plant loses a considerable amount of food (sugar) when you harvest them. Restoring food reserves and generating a new spear is a stressful process. 

Therefore, for the first two growing seasons, it’s best to refrain from harvesting spears and let your asparagus plants dedicate all their resources to growth and maintenance. 

That way, by the third year, your plants will be well-established and in perfect condition to produce large, nutritious, and succulent spears. 

You can begin harvesting spears in the third year, but it’s recommended not to harvest throughout the two-month harvesting period. You should instead harvest spears for two weeks then let them develop into ferns to further promote the health and integrity of your asparagus crowns. 

By year four, you can harvest spears freely, stopping only after the two-month harvesting period. 

Asparagus plants live for decades, so you’ll be able to harvest annually for years to come, which makes the wait-time well worth it. 

We’ve discussed when or when not to harvest asparagus spears. Let’s also go over the actual act of harvesting a spear itself.

Harvesting Spears

You can cut the spears with a knife or snap them off the ground with your bare hands. Either way works; it’s ultimately a matter of personal preference. 

Spears don’t offer much resistance to being snapped if you’re harvesting them at the right time.

If you use a knife, make the incision at ground level so you don’t leave an edible chunk behind. Also, use a sanitary knife to prevent the spread of disease. 

Once harvested, asparagus spears will spoil pretty quickly and need to be refrigerated or frozen for long-term use. 

Here’s some more in-depth advice from the University of Minnesota.

When Should You Cut Down Asparagus Foliage?

Asparagus plants will develop tall ferny foliage once they’re done producing spears. 

As with all plants, asparagus needs pruning and cutting back to stay in tip-top shape. 

Don’t Cut the Foliage Down Right After Harvesting Spears

Harvesting season ends sometime around June, at which time you should pause any and all harvesting and let any new spears develop into ferns. 

If you’re a novice gardener, you may think it best to cut back the ferns at this point and let things be taken care of until next spring. However, doing so would be a mistake. 

The tall, green, ferny foliage has a purpose. It absorbs sunlight so the asparagus plant can carry out photosynthesis. In preparation for winter, your asparagus plants need the remaining few months of full-intensity sunlight to stock up on food and resources. 

Asparagus plants are perennials that go dormant in the winter. When they reawaken after the cold has passed, they rely on food stores from the previous year to grow new spears. 

So, if you cut back your asparagus’ ferns too early, you’ll compromise the next year’s initial harvests. 

Wait for the Foliage To Die Naturally From the Cold 

Since you shouldn’t cut back your asparagus plants after spear harvesting is over, it makes the most sense to wait until they die naturally from the cold. Until then, the ferns will help with photosynthesis. 

Once winter sets in, the ferns will die quickly. They’ll lose their lively, vivid texture and turn yellow, then brown. Once you see the color change, you can safely cut your asparagus plants down to the ground and dispose of the spent foliage or add it to your compost bin

You should cut back the dead foliage now because if you leave it be, it will likely be infested by pests such as the notorious asparagus beetle. 

Also, you should mulch your asparagus bed during winter to provide the crowns in the soil with some additional protection against the cold. 

Cut the Foliage Down in the Early Spring

If you don’t cut the dead foliage in winter, you must cut it by early spring before new spears begin to grow because spears will get in the way and make it difficult to cut dead ferns down to the ground. 

Cutting back in the early spring is suboptimal—you risk damaging growing tissue and hampering the impending growth. It’s better to cut back your asparagus plants in the winter. 

But, at this point, it’s your only option. Leaving dead foliage standing is not advisable due to the heightened risk of disease and pest infestation. 

Cut and Prune As Required During the Growing Season

Cutting and pruning are two very important practices in the gardening world. You don’t have to restrict yourself to carrying them out once per year. 

Routine pruning during the growing season can be quite beneficial in keeping your asparagus plants looking clean and tidy. But the benefits go beyond mere aesthetics. 

You can help keep your plants healthier and prevent infections from spreading by cutting off damaged or diseased material. 

Regardless of when you choose to prune or cut back your asparagus plants, use sanitary cutting tools to curb the spread of diseases.

Pruning shears, trimmers, and knives are all viable options, although some are more convenient than others. 

You can sanitize your cutting tool between pruning rounds with diluted bleach (1 part bleach to 9 parts water). Alternatively, wipe the blades with 70% isopropyl alcohol.

Final Thoughts

If you don’t cut your asparagus plants, the spears will develop a fibrous layer, toughen up, and lose their prime taste and texture. You’ll miss out on potential harvest since spears only grow for a limited part of the year. 

The unharvested spears will fern and increase seed production, which can cause overcrowding down the line. 

If you don’t cut down the ferns of your asparagus plants in the fall/winter, they could get infected by pathogens and pests. In this case, you’ll still have the opportunity to cut down the plant in the early spring, although it’s suboptimal.

Alexander Picot

Alexander Picot is the principal creator of TheGrowingLeaf.com, a website dedicated to gardening tips. Inspired by his mother’s love of gardening, Alex has a passion for taking care of plants and turning backyards into feel-good places and loves to share his experience with the rest of the world.

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