(Backyard Gardener - Photo Illustration - MetroCreativeConnection)

Hello Mid-Ohio Valley Farmers and Gardeners! We definitely had a taste of summer over last weekend, as temperatures rose into the mid-eighties. However, we are back to reality with more moderate spring temperatures this week and even a freeze warning. This is why I always recommends waiting till Mother’s Day to plant tender annual flowers and warm season vegetables.

I consider Mother’s Day as the starting point for planting summer vegetables as the threat of frost is most likely behind us. I know, many gardeners are chomping at the bit to transplant tomatoes and peppers. Just wait a little longer. There is still time to plant cool season vegetables but get them in the ground as soon as possible. If it gets hot early, they will bolt (flower).

This week let’s talk asparagus, a great perennial vegetable for the garden. Asparagus (Asparagus officinalis) is one of the first crops harvested every spring. It produces good yields, has many health benefits, comes back year after year.

Fresh asparagus can be prepared in many ways (including being wrapped in bacon!) and contains glutathione, a potent antioxidant. It is well known for its detoxifying properties and is a good source of fiber, folate, iron, and vitamins A, C, E and K. Furthermore, it is a natural diuretic which may be beneficial for individuals with high blood pressure and other heart-related conditions.

Asparagus is always an interesting conversation piece, so let’s get some of these topics out of the way. Yes, eating asparagus may make your pee smell funny. Our bodies convert asparagusic acid into sulfur-containing chemicals that stink–but some of us are spared from the pungent aroma (anywhere from 20 to 40 percent of the population can’t detect the smell but it is there).

Yes, purple asparagus is an actual variety, but white asparagus is not a special variety. When the spears emerge from the ground, the sunlight turns the stalks green, and then six inches of dirt is piled on top of the plants so that the stalks can grow underground. When the tip breaks the soil surface, farmers probe under the ground with a special knife to cut the stalk, which is now all white.

Keep in mind asparagus is a perennial vegetable, so think long and hard about where you are going to plant. Asparagus beds may last 20 years, so site selection is crucial. Asparagus loves sandy soils, so it does not tolerate wet conditions. Your planting site must be well-drained with loose, rich soil.

This vegetable likes it dirt sweet (alkaline), so you may have to add some lime to raise the soil pH to at least 6.5. Work the lime deep into the soil so it can start to incorporate immediately. Research at Michigan State University shows that low pH in asparagus fields (below 6.5) are more conducive to the growth of the Fusarium fungi. Fusarium Root Rot is generally what eventually kills asparagus plants.

I receive a few calls every year about mowing asparagus ferns, so I will explain how this perennial vegetable grows. The plant is composed of ferns, crown and a root system. The ferns are not true leaves but are stems that will capture and transfer energy to the crown.

The crown is a collection of rhizomes (modified roots) and lateral roots that will initiate new ferns. Spears which are not harvested develop into a large fern which manufacture and store energy in the crown. Thus spears (what we harvest to eat) are actually immature ferns.

Ferns should never be pruned or cut back. The asparagus fern is the “factory” that supplies energy to the crown and storage roots for next year’s crop. If you want to clean up, wait till after the first frost and you can mow the ferns down.

You need to plan ahead for an asparagus planting. Asparagus is usually propagated with crowns, which are transplanted in a deep trench. Dig the trench four to six inches deep and use an inch of compost or apply good phosphate fertilizer before planting. Space the crowns 12-18 inches apart in the trench.

Keep rows about four feet apart so the ferns can close canopy and shade weeds during the summer. Cover the crowns with about 2″ of soil, and as the ferns emerge and grow, gradually fill-in the furrow through the summer.

I recommend ordering one year-old grown crowns from a reputable nursery. They are small enough that they don’t suffer so greatly from transplant shock. Even two-year old crowns don’t do as well as year-old crowns because they are so big that the transplant shock cancels out any benefit from the larger crown size.

Many home gardeners enjoy growing plants from seed. However, this is very difficult with asparagus. This is why WVU Extension recommends planting year old crowns. Researchers have tried direct seeding without much success. 

Let’s talk varieties. Asparagus is dioecious, which means there are separate male and female plants. Male asparagus plants produce more spears relative to female plants. Female asparagus plants produce numerous bright, red, berry-like fruits with seeds that can become volunteer weeds in the garden or field. Male plants produce more spears than female plants because no energy is put into developing fruit and seed.

I suggest planting the improved hybrid all male varieties, which includes all the “Jersey” types developed by the Rutgers University Breeding program. These include Jersey Supreme, Jersey Knight or Jersey Giant. The yield advantage for hybrids (Jersey types) is about 50% greater compared to non-hybrid varieties.

Older asparagus varieties introduced in the United States are mostly one of the Washington varieties, Mary, Martha or Waltham Washington. These are unimproved, non-hybrid varieties. In a non-hybrid bed, you will have an equal number of male and female plants. You will not be able to tell the difference until berries appear on the female plants and your asparagus bed will be a lot less productive.

Asparagus require a lot of patience. Delay harvesting spears until the third year of your planting. This will send all the plant’s energy into developing a strong root system. Harvest asparagus when it is about five to eight inches tall, by snapping off spears.

The picking season lasts about six to eight weeks, harvesting every one to three days. Snapping it off generally breaks the spear off above the woody, high-fiber section, eliminating the need to trim snapped asparagus. Field harvesting should cease when the majority of spears have a diameter the size of a pencil called whips.

Most of the fiber in asparagus is in the skins, making the larger spears much more tender (opposite of what you think). Asparagus has a very short shelf life and should be immersed in cold water after harvest and immediately refrigerated to maintain quality. Contact me at the Wood County WVU Extension Office 304-424-1960 or e-mail me at jj.barrett@mail.wvu.edu with questions. Good Luck and Happy Gardening!