Asparagus is one of the first plants to join us in the spring! It’s a perennial, so once it’s established, the tender spears will come back every year. Its fernlike foliage is also beautiful as an ornamental.
Since it will stay in the same place for a long time, it’s important to find a place where it can grow well. It takes three to five years for an asparagus plant to reach full maturity, but the harvest is well worth the wait. After they get going, you’ll have asparagus spears to harvest for more than a month every spring.
Asparagus spears are the straight, scale-like tips of the plant’s young shoots. Young shoots should be handled with caution, as contact dermatitis is possible.
At the end of summer, the female plants make red berries that are toxic to humans. The foliage develops into an airy, light-green fern later in the season, and in the fall, it turns a golden hue. This perennial is often planted in early spring from roots or crowns.
Botanical Name: Asparagus officinalis
Common Name: Asparagus
Plant Type: Perennial vegetable
Hardiness Zones: 3 to 10 (USDA)
Sun Exposure: Full sun
Soil Type: Loamy, sandy
Soil pH: 6.5 to 7.0 (Neutral, acidic)
Height: 4 feet tall
Bloom Time: Summer, fall
Flower Color: Yellow, green
Native Area: Europe, Africa
Quick Guide: Planting, Growing & Caring for Asparagus Plant
- Plant asparagus in the spring in a sunny location with nutrient-rich, well-drained soil.
- Asparagus takes a few years to grow up, but it can produce food for 15 to 30 years, so choose a place to plant it where it can grow undisturbed for a long time.
- Asparagus is a perennial that requires good soil if you want to see good harvests for years to come from your efforts.
- Add a lot of organic matter to the soil and keep the pH level between 6.5 and 7.0.
- Regular watering is necessary for asparagus, especially while it is young. For the first two growing seasons, give it 1 to 2 inches of water per week, and then 1 inch per week after that.
Asparagus Plant Care
Asparagus is hardy enough to be grown in most temperate climates, but it produces the best results in areas with longer, cooler winters.
The edible portion of the asparagus plant is the young stem shoot, which develops in spring when soil temperatures exceed 50 degrees Fahrenheit (10 degrees Celsius).
The most important thing to remember about asparagus is that it should not be harvested during the first two seasons. Before you can successfully harvest these plants, you must allow them to get established. But asparagus beds can produce harvests for as long as 30 years, so the wait is well worth it.
Since asparagus grows for such a long time, it’s important to plant the best kind for your area. We’ve shared the best varieties below that we recommend you check out.
Asparagus plants thrive in full sun. Day long sunlight not only encourages production but cuts down on disease as well. Without sufficient everyday sunlight, you will have thin spears and weak plants that are prone to diseases and problems.
If you want to grow asparagus, a long-lived perennial, it’s worth your while to invest in better soil. Work in plenty of organic matter and keep the pH of the soil neutral between 6.5 and 7.0. It’s difficult to change soil pH once the crowns are in.
Generally, this soil should be the best you can make it. After all, it will go mostly undisturbed for at least a decade.
Remove any weeds and large stones from the area as well. The soil must be well-draining so that plants never sit in water.
Asparagus needs to be watered regularly, especially when it is young. Give it 1 to 2 inches of water per week for its first two growing seasons, and about 1 inch per week after that.
If you give them a good start when you plant them, you’ll have less trouble with them in the years to come. It’s a good idea to add a soaker hose or drip irrigation to the asparagus bed.
Temperature and Humidity
Asparagus thrives in temperatures between 70 and 85 degrees Fahrenheit during the day and 60 and 70 degrees Fahrenheit at night throughout the growing season.
As the soil temperature hits 40 degrees in the spring, it will begin to develop shoots. After the shoots begin to grow, any frost will harm them. Temperatures above 85 degrees Fahrenheit or below 55 degrees Fahrenheit may inhibit growth.
Add compost, an all-purpose organic fertilizer, and rock phosphate, a natural mineral powder that helps roots grow, to the trench when you are preparing your asparagus bed. These nutrients will assist in establishing a healthy, strong root system in your asparagus.
Asparagus plants benefit from an annual top dressing of compost, which also helps maintain the soil’s richness. This can be done in the early spring, before any shoots sprout, or in the fall, after the fronds have died back and been trimmed to the ground.
Due to their high nutrient needs, asparagus plants benefit from a mid-spring application of fertilizer.
Before the new growth starts each year, asparagus plants need to be cut down to the ground. The timing is entirely up to you.
The stalks can be cut off in the fall or winter when the leaves have naturally withered and become yellow. Asparagus beetles and other pests can’t overwinter in the dead stalks if they’re removed early enough.
On the other hand, leaving the stalks standing throughout the winter has the benefit of allowing snow to collect in the plant waste, protecting the asparagus crowns from freezing temperatures. In any case, before the spring growth begins, the dead stalks must be removed.
What’s the Difference Between Green and White Asparagus?
White asparagus is the same plant as green asparagus.
However, it turns white through a procedure known as blanching, which deprives the plant of light so that it cannot photosynthesize. This is done by placing soil or plastic tunnels over the spears as they grow.
If the harvested spears are quickly refrigerated to stop the fiber from developing, the end product is smooth, white, and nearly fiber-free.
Types of Asparagus
Asparagus plants can be either male or female. Male plants do not invest energy on berries, allowing them to be up to three times more productive than female plants. This is why it is common practice to grow male asparagus plants.
Let’s check out different varieties of asparagus plants that you can grow according to different zones and climate conditions:
Zones 4 to 6
Zone 4 through 6 gardeners can choose from a wider range of varieties, such as the ‘Jersey King,’ ‘Jersey Giant,’ and ‘Jersey Knight.’ Female plants produced from older varieties such as ‘Mary Washington’ and ‘Martha Washington’ may be less productive than male plants.
Late-emerging cultivars, such as the ‘Guelph Millennium,’ are less likely to be harmed by spring frost in regions with lower average temperatures.
Early and heat-tolerant varieties such as ‘Apollo’ and ‘UC-157’ produce well before the weather warms up.
Cooking naturally changes the color of purple asparagus from purple to green. Most purple varieties have fewer spears that are thicker. ‘Purple Passion’ is a delicious but not exclusively male variety.
How to Plant and Grow Asparagus Plant
Although the spears on your asparagus may not be large enough to pick for up to three years, you should nevertheless prepare the bed so that you get the best possible results.
Asparagus grows back every year, so you’ll need to set aside a spot in your vegetable garden or, better yet, build a separate bed. In the first couple of years, they will not spread out much, but once established, they will quickly fill in.
Heirloom varieties need more room because they have both male and female plants. This means that they will produce seeds and spread themselves. You don’t need as much space for newer hybrid varieties because they only generate male plants that do not yield seeds.
When preparing the bed, remove weeds and continue to do so while the asparagus plants are young. Asparagus roots generate a dense mat that makes it difficult to eradicate weeds.
Mulch the bed with straw or leaves to discourage weeds, but avoid interplanting asparagus with other plants because it dislikes nutrient competition.
How to Plant Asparagus
Plants can be started from seed four weeks before the last forecasted frost. But if you plant seeds, your wait time will increase by a number of years.
Most people find that starting with crowns, which are commonly available in the spring, makes growing asparagus easier.
They appear to be a worn-out string mop but are in fact still very much alive. In contrast to many plants, the roots of asparagus crowns can tolerate some air exposure, and they are typically sold as bare roots. They should look fresh and firm, not dried out or mushy.
A trench is the most popular approach to planting asparagus crowns. In the spring, dig a 12-inch-wide and 12-inch-deep trench.
Mix your compost, fertilizer, or other organic matter together and make mounds about 18 inches apart. The crowns should be spaced 12 to 18 inches apart because asparagus needs space to grow.
Place the crown atop the mound and spread the roots along the sides. The soil line should be about 6 inches below the top of the crown. Water the roots well once they’re in the trend. Then, add about two inches of soil over the crowns.
Don’t completely fill the trench. At this point, you only need a few inches of soil to cover the crowns. Fill the trench with additional soil as shoots emerge until the trench is filled to ground level.
How to Harvest Asparagus
In most situations, harvesting your asparagus spears will not begin until the third year after they are planted. They require that time to establish themselves and strengthen their root systems. This is particularly true during the first year after planting, when the shoots are still small.
During the second year, some gardeners harvest spears that are the thickness of a pencil or thicker. Patience is essential for growing strong, established asparagus plants.
You should be able to harvest for roughly two weeks by the third year. After the initial harvest, leave the new spears alone to grow. The attractive, airy foliage that feeds the plant will be produced by fronds that spread out from the spears.
As the tip becomes loose in the fourth year, start harvesting spears that are 5 to 7 inches long. The diameter is irrelevant at this stage.
The spears can be snapped off or chopped with a knife just above the soil line. Be careful not to cut the later shoots that are still underground and have not yet emerged if you use a knife.
In the fifth year, harvest should last for approximately four to six weeks. In future years, the shoots will keep emerging from the ground all through spring. The shoots will turn spindly after you’ve been harvesting for more than a month and the temperature starts to rise.
Let the plants to develop their mature ferny foliage, which will nourish the roots for next year’s harvest.
Asparagus plants can live for 20 to 30 years. They can be divided or transplanted if they get overcrowded or would benefit from a change of location.
Common Pests and Plant Diseases for Asparagus Plant
Asparagus often face few issues in the garden. Planting hybrid kinds that are resistant to Fusarium wilt is the best way to protect yourself from this disease, which can affect older varieties.
The asparagus beetle causes the most damage. As the spring spears begin to appear, be on the lookout for them. Afternoons tend to be peak activity times for them.
When there are only a few beetles, you can kill them by handpicking them and dropping them into a bucket of soapy water. In any other case, neem oil that has been diluted should be enough to keep them in check.
Final Thoughts: I Grew Asparagus, Now What?
Asparagus is a delicious and versatile vegetable that can be easily grown in your own backyard. Once you’ve successfully harvested your homegrown asparagus, you might be wondering how to prepare and enjoy it in the kitchen. If you’re new to cooking asparagus, fear not!
This comprehensive guide on how to cook asparagus will walk you through different methods, such as how to cook asparagus in an oven, in a pan or on the stovetop, helping you to make the most out of your fresh harvest. With step-by-step instructions and handy tips, you’ll be serving up mouthwatering asparagus dishes in no time!
Eric Vinje founded Planet Natural with his father Wayne in 1991, originally running it as a grasshopper bait mail-order business out of a garage.
Eric is now retired, but is still a renowned gardener known for his expertise in composting, organic gardening and pest control, utilizing pesticide-free options, such as beneficial insects.
Eric believes when you do something good for the environment, the effects will benefit generations to come.
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