Garden Notes: Green Shoot and Crown Root - Planting an Asparagus Bed

Asparagus is another crop that spreads by runners, although it is a bit pickier about growing conditions and harvesting than raspberries. It’s one of those legendary foods that are so much better fresh from the garden that they almost seem to be a different vegetable entirely from what we can get in the store. If you have space, they are well worth the effort and patience it takes to grow your own. Most of their fussiness is about getting them planted just so; once established, they require little maintenance except regular water and yearly applications of mulch, and perhaps some amendments to keep the pH right. This is the season best suited to planting asparagus from dormant crowns, so if you’re interested in having your own asparagus patch, set aside a space for that’s just for asparagus, and get to digging! Asparagus is a perennial crop that can last for 5-15 years under the right conditions; it doesn’t like to have its roots disturbed, though, so it needs to be set well away from areas where annual crops are planted and dug up every year. The soil should be rich and amended with plenty of organic matter. Asparagus requires well-drained soil and regular watering to produce its best crops. And it requires a monumental amount of patience not to harvest any for the first 3, yes 3 years!


See, asparagus shoots are just the beginning of an asparagus plant; if not harvested, the thin green pencils of asparagus that we know from the grocery store will unfurl into feathery wands that resemble asparagus ferns, to which they are closely related. It is these fernlike leaves that supply the asparagus plant with energy. We harvest the shoots before they can begin to photosynthesize, but at some point in the season, depending on how old the plants are, the gardener must stop harvesting spears to allow them to grow into fronds that will nourish the plant throughout the growing season. Oh, the self-restraint that is required, once you have tasted the spears fresh and raw from the garden!

Further complicating matters is that asparagus are relatively slow growers. It is advisable not to harvest the first spears until the third spring after planting, and even then, the harvest should be limited to no longer than 2 or 3 weeks. In later years, the harvest can be stretched, from 6-8 weeks for a 4-year old patch, and on up to 2 months of harvesting for an established patch. Each year, it is the responsibility of the gardener to stop harvesting those luscious spears, in order to let the patch recharge for next year.
An ideal asparagus patch, according to Pam Pierce, whose Golden Gate Gardening we have referenced for this article, would be about 45 square feet, or 3x15 feet. “An asparagus lover’s dream,” she calls it, fit for one person who really, really loves asparagus. It’s worth setting aside some space, even if you do not have this much room to dedicate to asparagus; even 5 plants will provide a few delicious meals or fresh garden snacks. Plan on each asparagus plant needing an area at least 1 1/2 'x 1/1/2’. The mature fronds will grow to be 3-6 feet tall, so make sure that they will not shade out other plants with their height.
asparagus crowns

Planting and Care

The asparagus crown looks something like a great dirty octopus. Okay, they have more than eight “legs”, but perhaps it is a useful image; the crown, or top, of the octopus, is a round coin shape that goes closest to the surface of the soil, and the legs or tentacles hang down into the soil, spreading out gradually. The crown sends out shoots upward, that grow into the spears we eat.

prepping your soil
Choose a spot in the garden that will be set aside just for asparagus. Full sun is great, but asparagus will tolerate partial shade, and may even appreciate a bit of protection from burning autumn afternoon sun in really hot inland areas. The pH should be between 6 and 7, neutral to just a little alkaline. adding bone mealAdd lime, at an approximate rate of 2.5 pounds per 50 square feet, per year, to maintain alkalinity if the surrounding soils tend to acidity.

To plant your asparagus, amend the soil well with compost or well-rotted manure. In this rich soil, dig trenches that are at least a foot wide and 10-16 inches deep. Put a layer of well rotted compost or manure into the bottom of the trench, several inches deep. You may also want to work in a slow release organic fertilizer such as bone meal here, something that feeds the growing roots rather than the green leaves of the plant; in other words, a fertilizer higher in phosphorous than nitrogen.

Determine where in the trench each of your asparagus plants will go. In the bottom of the trench, at each planting location, build a small mound of mixed soil and compost, in a kind of volcano shape. The crown should be placed on top of these mounds, with the roots draped all around the sides of the mound. This shape will cause the roots to spread out like a pyramid below the ground, ensuring that they are not bunched together in a way that could compromise their future growth and ability to find water and nutrients. Remove any damaged or broken roots before planting.
planting asparagus crowns

Plant all crowns in the trench as directed, and then fill in the trench to cover the tops of the crowns by about 2 inches.composte This should still leave a shallow trench of 3 or 4 inches deep, which will act as a basin to catch water and mark where your plants are planted; it will also ensure that the young crowns are not smothered by heavy dirt, or buried too deeply to send up shoots. As the plants grow throughout the season, the trenches can slowly be filled in as new compost is applied and the garden is mulched; by the next winter, the trench should be filled to the level of the surrounding soil.marked asparagus plants The crowns will grow to appreciate this covering of earth, which protects them from surface disturbances, frost damage, and moisture loss. Regular yearly mulching with compost, straw, and well-rotted manure can help maintain this protective covering.

As the season progresses, asparagus requires regular deep watering to keep the soil moist. Mulch is a welcome addition once the pants are growing vigorously, to aid in moisture retention. A mild nitrogen fertilizer can be applied in the spring of subsequent years, before the shoots begin to sprout; this will stimulate the crowns to produce more shoots. A balanced fertilizer, or one that has a slightly higher proportion of phosphorous can also be applied mid-season, after the harvest is finished, which is especially helpful in soils that may be lacking in nutrition. (Sandy soils, I'm looking at you.)

In late fall, when the fronds begin to turn yellow, they can be cut to the ground and composted; watch out for their hidden thorns, though. They look soft and billowy, but they have secret, well-hidden thorns that can surprise an unwary gardener.

Phew! It’s a lot of information to bite off, all at once, but once they’re in the ground, asparagus can be such a rewarding crop. Asparagus is right up there with tomatoes, in terms of crops that are worth growing yourself for best flavor. Eat 'em raw or steamed, quiched or brined or pickled…but eat ‘em while you can! Asparagus crowns are in fresh and in stock in our edible nursery right now, but they won’t last long.

Over to You

It’s part of our mission here at Mountain Feed to help you grow beautiful, sustainable, gardens wether you have sprawling acres of farm or just a tiny plot along the highway. Stop by and say hello on Facebook, Twitter, Instagram or Pinterest. Or, as always, you can do it the old fashioned way and come by the store to speak with one of our in-house experts.