Agriculture Reference
In-Depth Information
Asparagus
ASPARAGACEAE
Asparagus (
Asparagus officinalis
) is a true delicacy among vegetables, often eaten steamed
or raw in salads. It contains easily digestible carbohydrates and proteins, including the amino
acid asparagine, which gives it its unique aroma. Asparagus acts as a diuretic and helps the
body detoxify; it is often recommended for those with an ailing liver or kidneys. Saponins
found in the shoots have been shown to prevent cancer. In our experience, older varieties are
tastier than newer ones. Growing asparagus at home seems to have gone out of fashion, al-
though it is fairly easy to grow and propagate. Asparagus shoots are naturally green (some-
times with hints of other colors) but can be grown blanched. German asparagus eaters swear
by these last, while the French prefer green asparagus or the colorful violet varieties that
have been bred there ('Jacq Ma Pourpre'). Green asparagus contains up to 2.5 times the
amount of vitamin C as blanched asparagus.
WHAT YOU'LL NEED
• 10 to 20 plants for seed production
• five plants for vegetative propagation
POLLINATION NOTES
Asparagus is a dioecious crop plant: plants produce either male flowers or fe-
male flowers exclusively. Insects deliver pollen from male plants to the flowers of female plants. Fe-
male plants produce fewer shoots than male plants, though those they do produce are thicker. Female
plants also have a shorter life span than male plants. For these reasons, commercial growers tend to use
male plants exclusively; these can often be recognized by their stereotypically macho names like
'Mars', 'Sieg' (victory), or 'Vulkan' (volcano). Nearly all commercial varieties of asparagus are purely
male varieties, older varieties have both male and female plants.
PROPAGATION
Plants are usually propagated vegetatively. We have been able to propagate asparagus
by seed but not so that the results are varietally pure: plants from seed are usable but are not necessarily
identical to the mother. Sow seeds in trays, transplant 2-3 in. (5-8 cm) seedlings to pots, and plant out
in late spring (12 in. [30 cm] rows, 4 in. [10 cm] within row). Dig up the following year and plant in its
final location, pruning rhizomes back to a uniform length of 4 in. (10 cm). Asparagus prefers light soils
(which are also easier to harvest in). Planting for green asparagus: dig a furrow 4 in. (10 cm) deep and
12 in. (30 cm) wide and set plants in flat, 10-12 in. (25-30 cm) apart. Planting for white asparagus:
plant deeper or establish raised beds. Adding manure and compost is beneficial in asparagus cultivation,
especially in the first two years. Asparagus can be harvested for the table starting in the third year, with
full yields starting in the fourth year. Plants can be harvested for edible shoots for 10 to 15 years. Har-
vesting blanched asparagus is very labor-intensive: shoots are cut once or twice a day, lest they grow to
