If you like asparagus you know that it is usually a pricey vegetable and is more abundant and cheaper at some times of the year that others. It also can be a very rewarding addition to the vegetable garden and has the advantage of being a long lived perennial that may give you a 6-8 week yield for 15-20 years once it gets rolling. Yes, there is a hitch; you shouldn’t harvest it the first year and only lightly the second year. The third and subsequent years you can really go to town.
Asparagus has male and female plants and the males. The female spears produce berries and are stringy while male spears are fat and tender spears. Varieties have been developed that are all or mostly male; look for the “Jersey” series, like ‘Jersey Knight’ and ‘Jersey Supreme’ and avoid the old standard ‘Martha Washington” (God bless her), that has a mix of male and females.
Most asparagus varieties require a freeze period to do well so if you live in a warm area look for varieties that were bred with this in mind. The University of California has developed ‘UC 157’ that does not need a freeze period and can tolerate heat in summer. Another variety, ‘UC 500”, also does well without a freeze period but can’t take heat.
Asparagus can be grown from seed or root but seed will take an additional year to harvest so most people buy roots.
Garden centers may carry asparagus roots in late winter or early spring but many good mail order sources are also available. Each root will provide about 1/2 lb. of spears so about 2 dozen roots will provide asparagus for a small family.
Order or buy plants so that you will have them when the soil temperature is about 50o F.
Plan to plant the roots as soon as they arrive. Give them a good soaking in a bucket of water (no more than over night) while you gather up you planting gear.
Good soil preparation is essential since asparagus is a perennial and will remain in the ground for many years.
Select a site in full sun where the soil is well drained. The asparagus plants will grow large after the harvest so a position in the back of the garden, on the north or west side where they will not shade other plants is desirable.
Dig trenches 1 foot deep, 1 foot wide, and 3 feet apart.
Half fill the trenches with a mixture of equal parts soil and compost or well rotted manure.
Add 0-46-0 (triple superphosphate) or 0-20-0 (superphosphate) fertilizer (at the rate of 1 lb. or 2lb. per 50 feet of row respectively) in the bottom of the furrow before planting. This form of phosphate will not hurt the roots but will do wonders for root and shoot growth.
Form mounds 6” high and 18” apart in the trenches with equal parts soil and compost or well rotted manure.
Set an asparagus crown on top of the mound with the roots spilling down the sides of the mound.
Cover the crowns with an inch of soil and water throughly.
As the spears grow, fill in the trenches with soil and compost until the crowns are about 3” below the surface of the soil.
Keep the asparagus well watered using a soaker hose if possible.
Fertilize every spring with manure or a complete fertilizer such as 5-10-10
Fertilize after harvest with a fertilizer high in nitrogen (first number)
Weeds are the biggest problem when growing asparagus and can lead to the demise of the bed due to resulting problems with diseases and pests.
Pull weeds by hand and cultivate carefully to avoid hurting the roots.
Slugs, snails and sow bugs and asparagus beetles can be a problem.
First year: no cutting; let the stems produce foliage.
Second year: harvest for a couple of weeks until you see the stems getting as thin as a pencil. Cut or break off at the soil line so to avoid hurting the crowns or emerging spears. Let the plants develop foliage so they can build up a bigger roots and more stems next year.
Third year and thereafter: cut spears when they are 6-8” tall and pencil size in diameter or larger for about 6-8 weeks each spring. Spears taller than 8” have passed their prime so let them develop foliage. As the weather warms you may have to harvest daily or even twice a day.
Asparagus can be kept fresh in the refrigerator for up to two weeks by placing freshly cut stems in a jar of water as though they were a bouquet of flowers.
Cut foliage in late fall when brown
Mulch with organic material avoiding peat moss or leaves that might form a crust on the bed that might reduce moisture up-take or inhibit stem emergence in spring.
Growing asparagus is a bit different from growing other vegetables mainly because of their perennial nature. Once you get the bed established, however, the tasks are weeding, watering, and fertilizing, all chores associated with any vegetable garden. If you like asparagus, a bed to pick from for weeks may be a dream come true.