Companion Planting with Asparagus: Plant with Basil, Parsley and Tomatoes.
Parsley and asparagus are mutually beneficial in promoting one another’s health and vigor. Tomatoes contain a substance called solanine, which protects against asparagus beetles; tomatoes also attract the natural predators of the asparagus beetle. Diseases: Asparagus Rust, Fusarium, Needle Blight, and Purple Spot. Pests: Asparagus Aphid, Asparagus Beetles.
Adverse plants: none.
How to grow: Asparagus must be grown in rich fertile soil (preferably sandy loam) in full sun (no shade), which helps to prevent diseases. This perennial vegetable is extremely easy to grow once established, which can take 2-3 years (3 years from seed) before you can harvest your first spear. Soil should have a Ph of 7.0 and a temperature of 50 degrees at planting. Soak crowns an hour or so before planting.
Preparing the bed: After amending the soil with good rotted compost or manure, plant asparagus crowns in trenches eight to twelve inches deep having a convex (arched or rounded) center running lengthwise to the trench. The middle of the asparagus crown is placed on top of the raised portion of the bed down in the trench allowing the long roots to gently rest on either side of the slope. Spread the roots out in the trench 12 to 18 inches apart and cover them with two inches of soil. As the hair like ferns appear cover them again. Do this until the trench is filled.
Asparagus plants are monoecious meaning each individual plant is either male or female. Some varieties of asparagus, such as ‘Jersey Knight’ and ‘Jersey Giant’ produce all male or primarily male plants, so they’re more productive. Male plants yield more harvestable shoots because they don’t have to invest energy in producing seeds. Choose an all male variety if high yields id your primary goal. If you like to experiment, you may also want to grow an heirloom variety or purple-stalked variety like ‘Purple Passion.’ With an all male variety, 25 plants are usually adequate for a family of four; plant double that amount for standard varieties. Ardent asparagus lovers recommend tripling these quantities.
Starting asparagus from one year-old crowns gives you a year’s head start over seed-grown plants. Two year-old crowns are usually not a bargain. They tend to suffer more from transplant shock and won’t produce any faster than one year-old crowns. Buy crowns from a reputable nursery that sells fresh, firm, disease-free roots. Plant them immediately if possible; otherwise wrap them in slightly damp sphagnum moss until you are ready to plant.
Leave winterkilled foliage, along with straw or other light mulch, on the bed to provide winter protection. Remove and destroy the fernlike foliage before new growth appears in spring; it can harbor disease and pest eggs. I prefer cutting the ferns out in the fall after several hard freezes and place more chips and not straw on the beds. Straw seems to attract slugs in my garden so I generally stay away from it.
In the North, like here in Idaho, start seedlings indoors in late February or early March. Sow seeds in damp newspaper and place them in a sunny window or under lights; use bottom heat to maintain a temperature of 770F. When seeds sprout, lower the temperature to 600 to 700 F. When tiny flowers appear, observe them with a magnifying glass. Female flowers have well-developed, three-lobed pistils; male blossoms are larger and longer than the female flowers. Weed out all female plants if high yields are desired. The following spring transplant the males to the permanent bed.
Problems: Healthy asparagus foliage is necessary for good root and spear production. Asparagus beetles, which chew on spears in spring and attack summer foliage, are the most prevalent problem. There are two kinds of asparagus beetles, one of which over-winters in fallen berries- so if you cull the females, you'll only have the other kind to combat. I've found that the females just don't thrive as well as the males- especially when conditions are less than ideal. Maybe the extra energy used to grow the berries taps them out. Or maybe it's that my Martha Washington’s just aren't a good as those Jersey Kings.
The ¼ inch long, metallic blue-black pests have three white or yellow spots on their backs. They lay dark eggs along the leaves; which hatch into light gray or brown larvae with black heads and feet. Control by hand picking; spray or dust seriously infested plants with insecticidal soap. These methods also control the 12-spotted asparagus beetle, which is reddish brown with six black spots on each wing cover. Asparagus miner is another foliage-feeding pest; it makes zig-zag tunnels on the stalks. Destroy any infested ferns. Planting tomatoes close by will attract predators that feed on asparagus beetles (see notes above), also it is said that powdered eggshell sprinkled on infected areas will detour and even kill beetles, slugs and snails. Planting parsley will increase vigor in asparagus plants.
How to grow seed: Asparagus is a perennial, pollinated by insects. Female plants have a fewer number of thick stalks. Male plants have a higher number of thinner stalks. The female plants will yield the seed berries. The berries are ready to harvest when they turn red and their fern-like top leaves flop over. Cut the tall berry stalk off the plant and hang it inside for ten days to dry. Remove the berries from the stalk and let them soak in a bowl of water for at least an hour to make them easier to open and remove the seeds. Dry the seeds on a paper towel for several days and store in a paper envelope or cloth bag in a dry, cool area. Asparagus grown from seed takes THREE years to produce asparagus for the table. It will then produce asparagus each year for about 15 to 20 years.
How and when to harvest: This spring plant should not be harvested the first year after planting and best not to harvest the second year as well. In warmer environments mature asparagus spears needs to be harvested twice a day because of its quick growth. Harvest spears when they are 9 to 10 inches tall. They can be snapped off separating the tender editable portion from the woody by bending them over with the thump, index and forefinger close to the ground, it is best to cut them below ground level to prohibit disease. It is thought by most people that the thick spears are woody and the thin spears are tender, not so; the thick spears are the earlier growth yielding the greatest harvest, the thin or skinny spears come at the end of the harvest season telling the grower that the plant is dwindling in strength. When thin spears equate to 40 to 50 percent of the harvest it is time to curtail harvesting for that year.
How to prepare for winter: Cut out all yellowing and green asparagus spears (stalks and ferns) an inch or two below ground level. Clean out all weeds. Rake back all of the old mulch (save, it will be added back later). Add azomite rock dust and new compost and mulch to the bed, then replace old mulch. Note: If you are using wood chips as a mulch/fertilizer just add the azomite and compost on top of the chips, the fall and spring rains will help this material penetrate to the root system without involving the above labor. (Love those chips!)
Health benefits: Asparagus is an excellent source of vitamin B6, calcium, zinc and magnesium. The vegetable also contains relatively high levels of beta-carotene, vitamin C, vitamin E, vitamin K (blood clotting and strengthening bones), thiamin, riboflavin, rutin, niacin, folic acid, iron, phosphorus, copper, potassium, selenium and manganese. Asparagus contains a unique carb called inulin, which remains undigested until it reaches the large intestine where it helps absorb nutrients better, cutting the risk of colon cancer.
The second century physician Galen described asparagus as “cleansing and healing” and research indicates that eating asparagus can help control diabetes, acts as a diuretic, prevents kidney stones, and reduces the risk of neural tube defects in babies.
Diabetes: Research at the Karachi University in Pakistan found that eating asparagus may help control type 2 diabetes. Their study was published in the British journal of Nutrition. According to the authors, asparagus “exerts anti-diabetic effects by improving insulin secretion and B-cell function, as well as the antioxidant status.”
As a diuretic and preventing kidney stones: According to an article titled: “Chemical constituents of Asparagus”, published in the journal Pharmacognosy Review, asparagus, “helps flush out the kidneys and helps in the prevention of the formation of kidney stones.”
Reducing the risk of neural tube defects in babies: Asparagus contains almost half a person’s recommended daily intake of folate. Folate helps prevent neural tube defects in babies. According to KidsHealth.org, there are various studies that have shown that “women who eat 400 micrograms (0.4 milligrams) daily prior to conception and during early pregnancy reduce the risk that their baby will be born with a serious neural tube defect (a birth defect involving incomplete development of the brain and spinal cord) by up to 70 percent.
Asparagus can naturally reverse cancer and is a good detoxifier; 10 to 15 spears daily to fight cancer. Most important it is a great source of Glutathione, which is the most significant Phytochemical in the body (a super antioxidant), which can protect the skin from sun damage, pollution and the effects of aging.
Risks: You should not eat asparagus if you are allergic to it. People who are sensitive to other vegetables belonging to the Liliaceae family (onions, garlic, and chives) should be cautious as they are at a higher risk of being allergic to asparagus.