HomeGardening Tips And AdviceThe Ultimate Guide To Growing Asparagus

The Ultimate Guide To Growing Asparagus


When Should You Plant?

Asparagus can be grown from “crowns” or seeds. Most gardeners begin with crowns since seed takes an extra year to mature. Growing asparagus from crowns takes 2 to 3 years before you can harvest it; growing asparagus from seed takes 3 to 4 years (which is why most gardeners choose crowns). Asparagus crowns can be planted 4 to 6 weeks before the last frost date in your area. Asparagus is a tough plant that can withstand most winters. However, mulching your asparagus with straw in the fall is an excellent idea for added protection. In southern regions, asparagus can be planted in the late fall and early winter, starting around mid- to late-January. While it is not required, you can start seeds or crowns inside 12 weeks before the last frost (see “Starting Asparagus Indoors” below).

Planting Locations

Asparagus prefers the sun, but it may also thrive in the shade. It should get at least 8 hours of sunlight per day. Asparagus prefers chilly weather as well. If the weather warms up too rapidly in the spring, it will bolt (go to seed). 60° to 65°F is the best temperature for growing asparagus. Planting asparagus along a fence line or on the border of your garden works well because it doesn’t mind competing with weeds and grasses (which also help keep the soil cool). Because asparagus is not a swamp grass, it prefers well-drained soil. Our soil is a little thicker in our region, but it contains a lot of small pebbles, so it drains quickly and is great for producing asparagus. Planting asparagus along the edge of a garden or along a fence is a great way to ensure that they get plenty of sunlight while not interfering with other landscaping options in your yard.

Soil Preparation

The ideal pH range for asparagus growing soil is 6.5 to 7.5. In soils with a pH of less than 6.0, asparagus will not grow. Asparagus is a nitrogen-loving plant. Composted manure, particularly chicken dung (organic if available), and bone meal are good sources of organic nitrogen (add 10 to 20 lbs. per 100 square feet). Because asparagus need a lot of phosphorus to create a robust root system, it requires a lot of it. Bone meal or rock phosphates are good sources of organic phosphorus. Asparagus also prefers a lot of potassium. Organic potassium sources include compost (including banana peels if you have them), wood ash (especially hardwood), and granite dust. If you’re beginning from scratch in a new garden area, keep in mind that an asparagus plant can live for up to 20 years, so you’ll want to apply plenty of the above soil nutrients before planting asparagus. Plant in an area free of Johnson’s grass (quack grass) if you can, as weed control becomes difficult once your asparagus has established, and it may stay in the same position for up to 20 years.

Selecting the Best Seed Varieties for Your Region

Because asparagus rust can be a concern in some places, check with your county extension to determine if rust-resistant types like Viking KB3, Jersey Giant, and Martha Washington are necessary. Another issue you should consult with your county extension is asparagus crown rot. The asparagus varieties Jersey Giant, Viking KB3, Jersey Knight, and others in the “Jersey” family are all resistant to rot.

Germination and Seeds

Asparagus seeds can be stored for up to three years after being acquired. Pre-soak your asparagus seeds in water or a compost tea to help them germinate faster for indoor planting (compost mixed with water). [A water temperature of 85° to 90°F for 4 to 5 days is recommended by the USDA.]

After your seeds have been soaked, plant them right away in flats or individual pots. The ideal soil temperature for germination is between 70 and 77 degrees Fahrenheit. At this temperature, they should bloom in 10 to 12 days. At 50°F, asparagus seeds take 53 days to germinate, 24 days at 59°F, and 15 days at 68°F. Above 77°F, germination times begin to rise. If you’re sowing seeds in your garden, 60° to 65°F is the ideal temperature range for your soil.

Let’s Get Started Indoors

Although asparagus is a cool-weather plant, and planting it inside isn’t necessary, we like to give you the choice with these simple instructions. In the part right above this on growing your seeds, I talked about how to start indoors. This will provide you with extra details. If you trust your government to know best, soak your seeds for 4 or 5 days as recommended by the USDA. Others advise soaking the seeds for only a few of hours before planting them in potting soil. Either option should suffice.

Use potting soil instead of garden soil to start your seedlings since garden soil may contain weed seed and/or germs that could hurt your plants in the warmer indoor temps. Make sure the pH of your potting soil is between 6.5 and 7.5. If you need to speed up the process, lime the soil. If you need to reduce it, add sulphur. While asparagus seeds can be planted in flats, tiny peat pots are better since the entire pot can be planted directly in the soil. This leaves the roots undisturbed, resulting in less shock when the plant is transplanted.


Growing asparagus in pots has been a topic of discussion. This is an option to explore if you live in a region where you can’t plant. If you’re going to plant asparagus in a container, make sure there’s enough of room for the roots to grow. A 5-gallon bucket is about as small as you can get…perhaps a little too small in diameter. I can’t verify this because we haven’t planted asparagus in containers and are relying on outside information on this topic. The recommended area for the roots of one containerized asparagus plant is 20″ x 20″ – I can’t verify this because we haven’t planted asparagus in containers and are relying on outside information on this topic.

If you’re going to use a plastic bucket or container, drill numerous 1/2-inch holes “So that the water drains efficiently, there are holes in the bottom and a couple on the sides (opposite each other). Put a couple of inches of small stones in the bottom of the container, then add your potting soil on top of that. The following part explains how to sow your seeds in pots or in your garden.


Asparagus seeds should be planted around 1/2 inch thick “deep in a peat pot, a container, or a garden Plant two seeds if you only want one plant. At least one seed will usually germinate. If both seedlings germinate, cut one off at the soil level to decrease the number of plants to one. Pre-sprouting seeds is also a good idea…wrap your seeds in damp paper towels and store them in a Zip Lock-type bag in a room that stays at 70°F. In 10 to 14 days, the seeds will germinate.

Move the seeds to a cool, bright spot, such as a windowsill, but out of direct sunlight, once they have germinated. If two plants emerge, carefully remove one or clip it off at the dirt level.

Getting Seedlings into Your Garden

Once the threat of frost has passed, move your asparagus plants outside for a couple of weeks during the day to acclimatise them to the outdoors. This is known as “hardening off,” and it aids in the preparation of your plants for transplantation. Once the fear of frost has passed, they will need to gradually acclimate to outside conditions, a process known as ‘hardening off,’ which can take anywhere from two to three weeks.

Initially, keep them in the shadow for the majority of the day, but gradually increase their exposure to sunshine. Maintain a moist but not damp soil. You may notice that the leaves yellow and fall as you move them in and out. This is natural since your plants are preparing to sprout new leaves that are more suited to the outdoors.

Transplant your seedlings to the garden after a few weeks. Cut the bottoms off peat pots (preferred), dig a small hole, and place the entire pot in the hole. If you used a flat, carefully take the plant with the soil intact, being careful not to touch the roots, and carefully set it in the little hole you’ve prepared; backfill and firmly press the dirt around the plant.


If you want to plant asparagus crowns, buy one-year-old crowns since they are less likely to break than older crowns. A good-quality one-year-old crown with 8 to 10 roots and a robust bud cluster has a fair chance of producing asparagus the following year. Plant the crowns 4 to 6 weeks before the last frost in the early spring. Soak the roots of your asparagus crown in warm water for a couple of hours before planting.

Trim the roots just a little (they can be quite tangled). Plants should be spaced about 18″ apart, whether in a trench or a series of 12″ deep holes. Compost, bone meal, manure, and other soil additives should be mixed into the ground that will be replanted around the roots and/or in the hole’s bottom. Remove any dead or rotted roots from the crown and lay it in the hole, bud side up, with the roots spread out. Spreading out the roots will be easier if the dirt is piled high in the trench. Cover the top with 2 to 3 inches of soil after packing earth around the roots. If there is still space in the trench, gently add dirt over the asparagus crowns as the summer progresses, as the crowns will tend to climb.

Planting Directly (planting seeds directly into garden bed)

Add your supplements to the soil and till or spade them in if you wish to plant your asparagus seeds straight in the garden. Soak your seeds in a Zip Lock container for 48 hours between moist paper towels. Keep the temperature about 85°F over the next 48 hours if possible. 4 to 6 weeks before the last frost, sow your seeds. At this time of year, the seeds will germinate slowly.

Plant your seeds 3 inches apart in three tight rows, about 15 to 18 inches apart “If you’re going to grow a lot of asparagus, space your next triple row about 4 to 5 feet apart. When you cover your seeds with dirt, make sure it’s moist and packed in tightly around the seeds, and that it doesn’t dry out. You can plant the crowns at varying depths if you wish to gather asparagus at different times (3 inches, 4 to 6 inches, 6 to 8 inches, 8 to 10 inches). Mulching half of your asparagus can also help; the exposed soil will warm up faster, allowing the asparagus to emerge sooner.

How to Grow Asparagus

Thin your seedlings to 12″ to 14″ apart once they’ve emerged. Mulch over your asparagus will keep the soil moist and reduce weeds while also delivering nutrients to the soil. It’s better not to harvest asparagus for the first couple of years, as this allows the roots to establish themselves. During the first couple of years, asparagus will produce “ferns.” These ferns are photosynthesis sensors and will help you grow asparagus spears next year.

Because it its strong roots, asparagus is considered drought-resistant. Good soil moisture levels, on the other hand, will result in a better crop. Continue to add composted vegetable and manure waste to your asparagus throughout the year for improved results the next year. When the foliage has turned yellow and the red berries have fallen off the plants, trim or mow the tops of your asparagus to 2 inch stubs after the frost.

Spray the ferns with a liquid organic leaf spray fertiliser when they’re growing in the summer when you’re producing asparagus. These sprays are highly recommended because they encourage your garden plants to produce more plant sugar during the photosynthesis process. As a result, your plant will be more vigorous, your garden will produce more, and your crops will have a better and sweeter flavour. They also come with a fantastic warranty!

Mulching and weeding

We’ve talked about utilising mulch to delay harvest, conserve soil moisture, and suppress weeds. What types and how much can be used? We use barley straw because it is readily available and inexpensive in our location. Grass clippings or cut leaves can also be used. Hay isn’t a suitable choice because it contains a lot of weed seed. 3 to 4 inches of straw mulch and 2 to 3 inches of grass clippings spread twice or three times during the growth season are my recommendations. The length of your growth season will determine this.

Remove the mulch to warm up the soil and speed up the harvest of half of your asparagus, as described above. To keep weeds at bay, don’t till around your asparagus. If you’re going to use a hoe, make sure you’re at least 6 inches away from the plants and only hoe the surface. Remove any weeds that are near to the plants by hand. Although asparagus is salt resistant, it is not recommended to use salt to control weeds.


Drip irrigation is preferable for asparagus, but if that isn’t an option, water heavily in the morning when the soil appears dry; the plants will dry out fully by afternoon. Watering your asparagus first thing in the morning will help it avoid fungus-related problems. During the summer heat, water 1 to 2 inches at least once a week; mulching, as previously noted, also helps keep the soil cool and maintains moisture. Overwatering or submerging asparagus is not a good idea.

In October and November, stop watering asparagus to allow the plants to turn yellow and go dormant. By the time asparagus reaches the age of four, it has established a root system that can reach depths of up to 48 feet “.. Irrigate every 2 or 3 weeks, but make sure to water deeply enough to reach the roots.

Considerations for Companion Planting and Rotation

Asparagus-friendly plants include:

Asparagus beetles are controlled with marigolds, parsley, and basil (more on that in the “Pests” section below). Asparagus is also reported to benefit from parsley. Dill helps to keep spider mites and aphids at bay. Aphids, spider mites, and potato beetles are all attracted to coriander. Comfrey contributes to the soil’s calcium, phosphorus, and potassium levels. It is also reported to be a good compost activator and helps manage slugs. Tomatoes are undoubtedly one of the best asparagus accompaniments. The asparagus beetle is repelled by the tomato plant, whereas the tomato plant is repelled by damaging root nematodes.

Plants that don’t get along with asparagus include:

In your asparagus patch, onions, garlic, and potatoes attract the wrong kinds of insects and predators. You don’t need to rotate your asparagus crop more than once every 20 years or so. However, before you plant it, pay special attention to the earth.

When Should You Harvest?

Cut asparagus stalks at or just below the soil level when they reach 6 to 9 inches in length, and definitely before they blossom. You may also harvest the spears by snapping them off; bend them quickly by gripping at the base of the spear. Harvest nothing the first year, lightly the second, and then aggressively the third. If you’re starting from seed, add a year to the preceding year. The asparagus harvest lasts around 8 weeks, and it is done on a daily basis. The spears will grow harsh and inedible if you don’t.

Clean up your asparagus patch so that those pesky asparagus bugs don’t have anywhere to lay their eggs. Large ferns will grow from any residual spears at the conclusion of the harvest, strengthening the plants for the following year’s harvest.


Once you’ve harvested your asparagus, it’s best to cool it down as quickly as possible (harvesting in the morning is also desirable if possible). An ice-water bath is a good way to quickly cool asparagus. Fill your sink with water and ice; once your asparagus is harvested, quickly cool it in the ice-cold water. Refrigerate your asparagus after it has cooled; it will keep for 2 to 3 weeks at 35° to 40°F. Over 40°F, it soon spoils. Blanched and frozen asparagus, canned asparagus, and pickled asparagus are all options. Jenny pickles asparagus for the holidays, and it’s a family favourite.

Natural & Preventative Solutions to Common Pests and Problems

Pests: the asparagus beetle, spotted asparagus beetle, and asparagus aphid are the worst insects to deal with when growing asparagus. Adults and larvae both feed on the spears in the spring, causing harm to the crop, and then defoliate the ferns in the summer, affecting the crop the next year.

Asparagus beetle defoliation can make asparagus more susceptible to fungal infections like fusarium. They appear in the spring around the same time as the asparagus and cause the asparagus to become brown, scar, or bend over. Asparagus beetles are oval in shape and have antennae. They are about a quarter of an inch long. They have six beige-colored dots on their back and are bluish-black in appearance.

Adult spotted asparagus beetles are more abundant in the Eastern United States, but they do the same thing to your asparagus. The larvae, on the other hand, don’t do much damage to the spears because they feed on the berries later in the year. They’re similar in size to asparagus beetles, except their backs are reddish-orange with a dozen black markings. They resemble ladybugs in appearance, however ladybugs have varying numbers of spots.

So, how can you get rid of these nasties? You can let your chickens forage on the beetles if you’re able to. Asparagus beetles are also susceptible to organic pyrethrins. If you have a tiny patch, you can patrol it every day and pick the bugs and their eggs by hand, dropping them in a pail of soapy water. Natural predators, such as the chalcid wasp or ladybug larvae, could also be introduced. The asparagus aphid is a European pest that first appeared in the United States in 1969 and has since spread throughout North America. Asparagus aphic creates “witches broom,” which is characterised by stunted, bushy growth. Pyrethrins or insecticidal soap sprays, on the other hand, are rather easy to regulate.

Factors in the Environment

Purple spot, asparagus rust, and asparagus crown rot are the most frequent diseases that affect asparagus. After the harvest, asparagus rust creates rusty orange to yellowish patches on the stalks. A disease with a long Latin name causes asparagus rust. As a result, early in the season, there are some light green lesions. Tan-colored blisters appear next, followed by black blisters that appear later in the season, usually after harvest.

Asparagus shoots can be killed or stunted by severe rust infections, decreasing the asparagus plant’s capacity to build strength for the following season’s crop. Your asparagus plants have rust if you rub your palm across the stalk and it turns orange. Planting resistant types before you have difficulties is the greatest approach to control rust: Rust-resistant cultivars include Viking KB3, Martha Washington, and Jersey Giant. A fungus with another long Latin name causes asparagus crown rot, but the short form is Fusarium, and it produces blight in the asparagus crown.

If your asparagus wilts in the summer heat, turns yellow before fall, or just dies, you may have a Fusarium infection. Your plants have been infected if the crowns become brown and you see that the roots are dying as well. Choosing disease-resistant types, such as Jersey Giant and Viking KB3, is the most effective approach to combat the disease. Finally, another long Latin word causes purple spot disease on asparagus plants. We wouldn’t have these difficulties with diseases if they didn’t use these big Latin names, it seems to me (that’s a joke…hahaha).

Purple spot sickness manifests itself as, well, purple patches. Usually found on spears that have been gathered. It survives the winter as black patches on the ferns that have died. 

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