Plant Nutrition / Asparagus

Asparagus / Asparagus officinalis
Nutritional value per 100 g (3.5 oz)
Energy 20 kcal 90 kJ

Carbohydrates	3.88 g
- Sugars 1.88 g
- Dietary fiber 2.1 g
Fat	0.12 g
Protein	2.20 g
Thiamine (Vit. B1) 0.143 mg	11%
Riboflavin (Vit. B2) 0.141 mg	9%
Niacin (Vit. B3) 0.978 mg	7%
Pantothenic acid (B5) 0.274 mg	5%
Vitamin B6 0.091 mg	7%
Folate (Vit. B9) 52 μg	13%
Vitamin C 5.6 mg	9%
Calcium 24 mg	2%
Iron 2.14 mg	17%
Magnesium 14 mg	4%
Phosphorus 52 mg	7%
Potassium 202 mg	4%
Zinc 0.54 mg	5%
Manganese 0.158 mg

Percentages are relative to US
recommendations for adults.
Source: USDA Nutrient database

An herbaceous perennial plant, growing 35-59 inches (100-150 cm) tall. It can grow for 15 years or more with proper care.

NUTRITION: Low in calories and in sodium. Has no cholesterol and is a good source of folic acid, potassium, dietary fiber and rutin. The asparagus plant is rich in amino acid "asparagine," derived from the name asparagus. The asparagus stalk is high in antioxidants.

Six asparagus spears contain: 135 micrograms (mcg) of folic acid, 545 mcg of beta carotene, 20 milligrams of potassium. Green asparagus is an excellent source of Vitamin C, having 6 times more than found in citrus fruit.

MEDICINAL: Second century physician Galen notes asparagus for its "cleansing and healing" properties. D. Onstad, author of 'Whole Foods Companion: A Guide for Adventurous Cooks, Curious Shoppers and Lovers of Natural Foods.' notes asparagus has long been recognized for its medicinal properties. "Asparagus contains substances that act as a diuretic, neutralize ammonia that makes us tired, and protect small blood vessels from rupturing. Its fiber content makes it a laxative too."

SOIL & PLANTING REQUIREMENTS:
Best time for planting is in early spring, as soon as the soil is dry enough for digging. Needs full sun and excellent drainage. Dig a trench 1 foot to 6 inches deep. Place a mound of compost every 18 inches along the middle of the trench and spread the asparagus roots evenly, over the mound. Fill in the rest of the trench with compost and water immediately after planting. After the plants are up mulch with shredded leaves to control weeds. Acidity (pH) Tolerance 6.8 to 6.0 pH
Salinity (Ec) Tolerance Very tolerant
HARVEST:
Give your new plantings a year to grow without harvesting. This will encourage root growth.

When you are ready to harvest; snap 3- to 6 inch tall spears off by hand. Avoid damaging spears still under the ground. Harvest in the morning when air temperature is cool. Immerse spears in ice-cold water, drain and place in plastic bags.

From a year old patch, harvest for 3 weeks / from older patches, harvest every 6 weeks.

Let the ferny tops grow to strengthen the roots for the next years crop.

IN THE FALL: Replenish the mulch with shredded leaves, a layer of compost or aged manure an inch or two deep over the asparagus patch.

INSECTS: Asparagus beetles, spotted asparagus beetle and asparagus aphid.

Asparagus Beetle: Both the adult and larvae feed on the plant. In the spring they feed on the spears, reducing the quality of the crop. In the summer they consume the ferns, reducing the food supply to the crown, reducing next years harvest.

Spotted Asparagus Beetle: The adult emerges later than the Asparagus Beetle and causes the same damage to the asparagus plant as the Asparagus Beetle. The larvae stage does very little damage as it feeds primarily of fruit and berries.

Control of these pests include allowing hens to feed upon them and / or using Rotenone or rotenone-pyrethrum mixtures are an organic control measure for larger acreages. Natural predators include a chalcid wasp and lady beetle larvae.

Asparagus Aphid: A native European, the Asparagus Aphid was introduced into the US in 1969. It feeds on "bushy" stunted new growth called, "witches broom." Can be controlled by natural predators and parasites. Can use insecticidal soap and rotenone-pyrethrum sprays.

DISEASES:

Fusarium causes crown, root rot and wilting. Established plants wilting of ferns and foliage turns yellow to tan. Diseased crowns will have a yellowish-red internal discoloration and the roots will be rotted. If the disease is severe, the bed will have to be destroyed but do not replant in same bed.

Asparagus Rust (Puccinia asparagi) can cause premature defoliation and death to if the ferns. This will reduce yields and increase the chance for root or crown disease. Rust is more severe during times of heavy rain, high humidity or abundant dew. Occurring most often after the harvest season, the first stage produces small yellow to orange spots first appear on the "needles." The second stage will show dusty brick-red pustules appearing on both shoots and needle, then they turn black. Increasing the planting distance between rows and orienting the rows toward the prevailing summer winds will help.

Needle Blight: (Cercospora asparagi) is a defoliating disease occurring around June, during periods of high humidity or abundant rain and warm temperatures. Affected ferns develop buff to gray, somewhat elliptical spots surrounded by a thin purple band. A bad infection will severely reduce yield the following seasons. Burning fern residue is best control.

Purple spot:a fungal disease caused by Stemphylium vesicarum, affects young spears. Infection causes sunken purple spots. Burying asparagus debris in late fall or late winter significantly reduces the severity of the disease and reduces the level of infection on young volunteer asparagus—an important control measure because infected volunteers are the source of fungal inoculum during the harvest period.