Tips for Asparagus Lovers

The asparagus I ordered a couple months ago finally arrived this past Saturday. I was wondering if my order had been lost so was surprised when the package finally arrived. Many mail order nurseries ship to Colorado based on Denver’s last spring frost, even when Grand Junction’s average last spring frost is a couple weeks earlier than Denver’s. If my order had been shipped earlier I would have had it planted and it would have been up just in time to be damaged by our last frost. Thankfully my order was shipped based on Denver’s weather.

I had grown Jersey Knight and Jersey Giant asparagus previously but decided to try Jersey Supreme this time. Jersey Supreme is supposed to able to produce one year sooner than most other asparagus. It is all male and capable of producing 10 pounds of asparagus per plant after the second year.

Purple Passion was the other cultivar I had ordered. This asparagus produces purple spears that are thicker but shorter than Jersey Supreme. Unlike Jersey Supreme but like most other asparagus cultivars Purple Passion can be harvested only sparingly the second year and then for 6 to 8 weeks starting the third year. Purple Passion is also called Viola and is said to be sweeter than other asparagus cultivars. Sadly Viola consists of both male and female plants.

Asparagus beds should last for 25 years or longer but often get crowded out by volunteer asparagus arising from seed dropped by female plants. When the selected variety is male this is not a problem.

I decided to plant Jersey Supreme in two rows four feet apart with eighteen inches between plants in the row. I dug a trench six inches deep and eight inches wide. This allowed me to spread out the roots evenly around the crowns with the buds up. I set the crown in the trench and then soaked the crown and trench and covered the plants with two inches of soil. As the spears grow I’ll continue to fill in the trench with more soil. While I could have filled the trench instead of doing this piecemeal, I like to see what is happening with the plant and decided to follow the older true and tested procedure of filling the trench in gradually.

Ohio State University reports that no matter how deep asparagus crowns were planted they always “floated” to a depth of 4.5 inches from the soil surface. The ultimate depth would vary depending on the soil type with crowns in a heavy (clay) soil being closer to the surface than crowns in a light (sandy) soil.

I prefer to put seeds and crowns in wet soil and then cover with dry soil. Covering with dry soil prevents the caking of the soil surface that happens when you water after you plant. I’ll also have less weed interference due to the layer of dry soil. After the crowns start growth I’ll check the soil moisture and water as needed.

The four foot spacing between rows permits access even when the crowns spread out and start to fill the area between the rows. The area between the rows appeared to be a waste of space. Since I had a package of mixed greens I watered the soil between the asparagus, scattered the package of seed and then lightly cover the seed with dry soil. The five varieties of lettuce, arugula, spinach, Swiss chard and other greens will be a great addition to our salads.


Purple Passion can be planted as close as 6 to 8 inches apart. The area I had available for this asparagus cultivar is a raised bed about five feet by five feet and next to my raspberry patch. Since I can get on three sides of this area it made sense to plant these crowns at the 18 inch spacing. I wanted to give these plants the best chance possible and this spacing seemed appropriate for the space available. I was able to plant six Purple Passion crowns in this area. The other 14 crowns were planted at the Mesa County Arboretum. These should create a very nice feathery screen at the back of the gardens and help cover up the chain link fence separating the Arboretum from the BMX track.

Many fact sheets recommend the addition of phosphorus. I did not add any phosphorus. A soil test showed there was already adequate phosphorus in the soil. Adding more would cause problems with other nutrients and mycorrhizal-forming fungi.

To ensure I created the best soil conditions possible for the asparagus, copious amounts of Mesa Magic was worked in two shovels deep. This compost will provide adequate nitrogen to give the asparagus a good start. Additional nitrogen will need to be added during the growing season to ensure the asparagus does its best. At the end of June I will fertilize the asparagus bed with a nitrogen fertilizer at the rate of 0.10 pounds of nitrogen per 100 foot of row. I’ll be using ammonium sulfate, a fertilizer with a nitrogen content of 20%. Thus I will be applying ½ pound of this fertilizer per 100 foot of row. If I was going to use an organic fertilizer I’d check out my list of organic fertilizers to determine their Nitrogen content and calculate the amount of the chosen fertilizer accordingly. This fact sheet is just one of many you can find in the vegetable pages at http://westernslopegardening.org/.