Growing asparagus in your vegetable garden at home is a great decision. You can grow asparagus from seed or crown, allowing easy access to them, which can be good for you since you no longer have to buy the expensive asparagus crowns.
The good news is that you can already create an entire field of homegrown asparagus plants with just the seeds you saved from heirloom varieties or the ones you purchased in stores. Get to know more about growing asparagus plants with this article’s guidance.
Quick Facts About the Asparagus
- Common and botanical name: Asparagus/Asparagus Officinalis
- Type of plant: Perennial vegetable
- Native areas: Africa, Europe
- Sun exposure: Full
- Size upon maturity: 5 feet tall; 3 feet wide
- Type of soil and pH level: Loamy, sandy soil; neutral to slightly acidic – around 6.5 to 7.0 pH level
- Hardiness zones: USDA zones 4 to 9
- Bloom time: Summer and fall
- Color of flowers: Pale yellow and greenish
Quick Description of Asparagus Plants
Asparagus is one vegetable that will be immediately ready for a spring harvest season. It is one of just a few perennial vegetables that thrive well. In other words, once it is already established, it is natural for their tender spears to return every year.
It also boasts of its ferny foliage that forms into an incredible ornamental. Growing asparagus plants in the majority of temperate regions is also possible. However, they will have more robust growth in areas with cool weather, especially those that experience long winters.
Asparagus also has young spears or stem shoots that are considered its edible parts. Expect these asparagus shoots to emerge once the soil temperatures exceed 50 degrees F during the early spring.
When planning to cultivate this plant, remember that you should never harvest spears during its first few seasons. You need to establish this plant before enjoying a more sustainable spring harvest.
The asparagus is worth waiting for, though. The reason is that once well-established, you can expect the asparagus beds to remain productive for at least ten to fifteen years. Some can even reach a long lifespan of up to thirty years.
What are Asparagus Spears and Crowns?
The asparagus spears refer to the edible parts of this perennial vegetable that is so popular in Minnesota along with rhubarb and horseradish. Technically, the spears are their stems. Asparagus spears come from underground buds found at the root system base.
Asparagus crowns, on the other hand, are other vital parts of the plant. They refer to the roots and buds. When learning these parts, you also have to know that leaving their spears to grow will cause them to form leaves referred to as asparagus ferns.
The plant needs to grow ferns because you only have around two months to harvest spears. The fern growth is necessary to recover and accumulate energy so it can grow the next year and season.
The fern develops energy that it will have to store in the plant’s underground part. This is what will help it produce a few spears the next year.
Asparagus Crowns or Seeds – Which One Should I Grow?
When growing asparagus, note that you can choose to start it from either the crown or the seed. If you plan to grow this crop in your backyard, starting asparagus from crowns will be a lot easier. Your decision to plant asparagus crowns has a higher success level in such a case.
Moreover, it allows you to harvest asparagus earlier. The crowns can be identified as the roots of an asparagus plant around one to two years old. These crowns can produce edible crops faster than asparagus seeds as they have this advanced growth stage.
Meanwhile, the seed crops are known for their early and tiny growth. You may also find it challenging to keep weeds away from them when they are still at their early growth stage. The presence of unwanted perennial weeds may negatively impact their production capability.
In addition, asparagus seeds are quite difficult to germinate. When you maintain the asparagus beds, there is a high chance of mistaking them for perennial weeds. This does not necessarily mean that you can no longer grow asparagus from seed.
You can still choose that if you are patient enough and willing to wait for three years to start having a sizable and huge harvest. On the other hand, the crowns can begin to develop edible crops a year after planting.
Aside from deciding whether you should grow asparagus from seed or crown, choosing the perfect location for your asparagus plant is also advisable. Remember that asparagus is a perennial crop, which is why it can grow in a similar space for several years. This makes it even more necessary to choose the perfect planting location.
In selecting the perfect location, remember that this plant requires full sunlight. This means you have to pick a spot where it can receive a minimum of eight hours of full sun daily. It can still tolerate partial shade but it will have a much more fruitful production when grown under the full sun.
In addition to providing sufficient sunlight, you must pick a spot with quality soil. Ensure that the soil is loose, fertile, and well-draining as it is what the asparagus needs to grow well.
Another important thing to remember is that the crop will grow in that same space for a max of twenty years. This makes it necessary to nourish the soil right from the beginning.
You can do that by putting in significant amounts of compost before planting asparagus. This can help improve the structure and fertility of the soil. Moreover, it can improve drainage, which is good since the plant requires well-drained soils.
To make the most out of compost, work in around two 5-gallon buckets of it for every five square feet of space. You may also find aged and composted manure useful instead of straight compost.
Whether you use the aged manure, the composted type, or the straight compost, ensure that the nutrients are properly worked in before you plant asparagus.
Choosing the Right Asparagus Plants to Grow
One crucial fact about the asparagus is that they could be either male or female plants. The fact that it has male and female plants means it falls under the classification of dioecious.
However, many gardeners prefer the male plants since they grow larger and can produce higher levels of new spears. Both the male and female can produce edible spears, though the ones with flowers that are all-female plants are those that can produce inedible and red berries during the summer.
Also, remember that while the male plants tend to provide a higher number of spears, they are usually more uniform and smaller than those produced by female plants. Many hybrid varieties, like the Jersey Giant, also contain male flowers. They are incapable of producing seeds.
The reason is that asparagus plants that only have male flowers are not keen on using energy for seed and fruit development. Despite that, the male varieties often have longer lifespans and higher spear production. Some find the female varieties problematic, as they also tend to develop unsightly weedy seedlings.
Actual Asparagus Plant Varieties
You can also access several species and varieties of asparagus, but note that the ones that receive the highest success rate in terms of growth are the Jersey Giant, Purple Passion, and Jersey Knight.
If you are planning to grow the plant in any part of Minnesota, the varieties that can grow successfully include the following:
- Millennium – This high-yielding and vigorous asparagus plant is a new variety from a university, the University of Guelph.
- Washington Series – Among the varieties in these series are Martha Washington and Mary Washington. One crucial fact about them is that they are among the open-pollinated varieties. They have lower yields compared to the varieties in the Jersey series but you are assured of their cold-hardiness.
- Jersey Series – Some examples are the Jersey Knight, Jersey Giant, and Jersey Supreme that continue gaining popularity because of their very high yield. Note, though, that they are among the varieties that can easily get damaged by temperatures that are around -30 degrees F so sufficient snow cover is necessary.
- Purple asparagus – This variety comes from breeding the plant to become purple. However, expect it to turn green after cooking. Expect the purple asparagus to have fewer but thicker spears.
There are also other varieties, like the Viking KB-3, open-pollinated, and purple passion, another open-pollinated variety in a purple shade. Many say that the Jersey Series is most successful because aside from being heavy producers, they also hold the best flavors.
Planting Asparagus Crowns
If you choose to plant asparagus crowns, the best way to do it would be through the trench method. Here’s how:
- To plant asparagus from its crowns, dig a trench in the soil around 8-inch wide and 6-inch deep.
- Begin putting the crowns. You should put them at the trench’s bottom and water them. There should be a consistent soil moisture to promote the good health of your plants.
- Cover with around 2-inch topsoil.
- Position the crowns a few inches apart – Provide a space of around 18 inches between each asparagus crown and around 12 inches between each row.
Once you notice the crown starting to grow, continue putting a couple more inches of soil. The goal here is to slowly fill in the trench. Expect it to be filled in within a few weeks.
With the help of this trench method, which also involves filling it with soil, you have an assurance that the plant will begin developing deep roots. Soon enough, this will lead to you harvesting spears and crops bountifully that will continue for several years.
Planting Seeds in the Asparagus Bed
While growing and cultivating asparagus from crowns would be much better, you can still choose to use seeds. Here are some tips when planning to start from seeds:
- Pick a spot that will serve as a nursery asparagus bed – This is where your young asparagus will grow during the first year. Pick a location in your garden for the nursery bed that is level. It needs sandy soil, too.
- Plant during the spring – It would be best for you to plant the asparagus seed during springtime. Each seed should be around an inch deep.
- Provide enough spacing – There should also be a space of two to three inches between each. The space for each row should be around a foot. After that, you can wait for around three weeks for the seeds to germinate.
- Ensure that the bed remains weed-free – Remember that asparagus grown from seeds is prone to get exposed to weeds. With that in mind, you must ensure that you do things to prevent the weeds from sprouting near them. Also, your asparagus seedlings may be incapable of competing with the strong growth of weeds, so keep the area weed-free.
- Mulch the asparagus bed – It is also advisable to mulch the bed. In this case, you can put in straw – around 4 to 6 inches – in late October. This should help in keeping the plant warm during the winter.
Caring for and Growing Asparagus
To guarantee your asparagus’s healthy and successful growth, whether you are starting it from crowns or seeds, you must focus on the following when caring for them.
Asparagus can thrive and grow well under the full sun. You need to provide its required daily sunlight; otherwise, it may become weak, making it vulnerable to problems. The spears it grows will also be quite thin and unhealthy.
To make a perennial vegetable, such as the asparagus, live long, it helps to spend time improving the soil before planting. Add some organic matter and ensure that the soil’s pH level is neutral, specifically around the range of 6.5 to 7.0.
Remove weeds and all large stones in the spot before planting, too. In addition, you need soil that is well-draining to prevent the plants from sitting in too much water.
You must also water it regularly, especially when the plant is still young. Provide around one to two inches of water every week during the initial two growing seasons of the plant.
As for the older ones, an inch of water every week would suffice. It also helps to integrate a soaker hose or drip irrigation into the asparagus bed to help it get just the right amount of water, preventing it from showing problems later on.
Humidity and Temperature
For the asparagus to grow during its entire growing season, you need to let it stay in a location with a temperature of around 70 to 85 degrees F every day. During the spring, expect the plant to start growing shoots once the soil temperature reaches 50 degrees.
One more thing to remember is that any frost that occurs after the beginning of the growth of shoots may lead to discoloration. There is also a high chance for the plant to grow slowly if the temperature goes below 55 or above 85 degrees.
Your asparagus can greatly benefit from adding an all-purpose organic fertilizer and compost to its trench. You can also add rock phosphate, a natural mineral powder capable of promoting the growth of asparagus roots.
Expect the soil to remain rich and well-nourished by top-dressing it with compost yearly. You can perform the top-dressing activity during the early spring before the emergence of shoots. You may also do it during the fall once you notice the fronds dying back and being cut.
Also, as a heavy-feeder, it can enjoy favorable benefits if you fertilize it during the mid-spring, specifically during its active growing stage.
When it comes to overwintering, the best step would be to cut the asparagus plant to the ground annually. You have to do this before the beginning of new growth. You can also choose the right timing for this.
For instance, you can take off the stalks in winter or fall once the leaves turn yellow and naturally die back. One benefit of removing the stalks early is that doing so can help prevent pests, like asparagus beetles, from overwintering.
You may also leave the stalks standing throughout the winter. The reason is that this plant debris will be capable of holding snow, thereby keeping the asparagus crowns fully protected during freezing temperatures. However, you still have to remove the dead stalks in springtime, specifically before the beginning of new growths.
Pests and Diseases to Watch Out For
The good thing about the plant is that it generally does not produce many problems while growing in your garden. The most common ones you will have to deal with would be Fusarium wilt, which occurs in older varieties, and the asparagus beetles.
You can avoid the Fusarium wilt by ensuring that you plant only the resistant hybrid varieties. As for the beetles, you can hand-pick them and then drop them into a bucket containing soapy water. If the beetles are already too many, you can control them with the help of diluted neem oil.
Frequently Asked Questions (FAQs)
How long does it take to grow asparagus?
They will likely mature within a year if you decide to grow it from crowns. On the other hand, asparagus plants grown and cultivated from seeds will be ready for harvest after around three years.
Is asparagus easy to grow?
Yes, it is fairly easy to grow. Note, though, that at first, your patience may have to be tested since you will have to wait a year up to three years before your first harvest, depending on whether you use the seeds or the crown.
Once you have established your asparagus plant, you will enjoy it even more since taking care of it will be much easier.
What are green asparagus and white asparagus?
The white asparagus refers to just a similar plant as the green asparagus. Note, though, that it becomes white because of blanching, a process that deprives your plant of the light it needs, causing it to be incapable of photosynthesizing.
Blanching happens if you cover the spears currently growing with plastic tunnels or soil. The result will be a smooth, almost fiber-free, and white asparagus. Just chill the harvested spears immediately to ensure the fiber does not form.
Does asparagus keep growing after you cut it?
Yes. As a perennial crop, asparagus can produce spears yearly for around ten to fifteen years. There is a good chance for this plant to live longer if you provide adequate care.
What conditions do asparagus need to grow?
This perennial will most likely grow when cultivated in a specific spot where it receives full sunlight. They also need temperatures around 75 to 85 degrees F during the daytime and around 60 to 70 degrees F during nighttime. As for the soil temperature, the requirement of asparagus for it to produce new shoots would be over 50 degrees F.
The asparagus plant is one of those vegetables or crops that are fairly easy to grow. Just treat them correctly, and you can harvest asparagus soon. You also need to give them proper attention and care, especially during their first few years, to ensure they will turn into high-yielding crops even with little maintenance.