By Irene Shonle, El Paso County
So, your gardening season may have been abruptly shortened by the Sept 8/9 cold snap, but as the days warm back up, you can begin to think about next year – a gardener is ever optimistic, right?
One of the things I am planning for next year is to plant asparagus – I will put them in a sunny corner of the yard next to my rhubarb and horseradish, in my perennial edible section. Perennial edibles are very rewarding, in that if you plant them well from the get-go, they will reward you for decades to come. I am prepping my asparagus bed now in the fall to make life easy for me in the spring when the crowns are usually more available.
To plan for an asparagus bed, take these things into account:
1. How many people will you be feeding? Are you crazy for asparagus, or more moderate? Plan on 5 crowns per person on the low end and 20 per person for those who can’t get enough.
2. How much room do you have (in a sunny location with good soil)? Ten crowns need about a 4-by-8-foot bed (Rows of asparagus should be at least 2 feet apart, allowing two rows to fit in a 4-foot wide bed). Asparagus is frequently sold in lots of 25 crowns, which would require about 80 sf.
Because asparagus is a one-and-done investment, it is worth taking a little time to prepare the bed properly. First, make sure you choose a sunny spot – asparagus will be more productive in full sun. The site also has to be well-drained. If you see pooling water after a rain (that sticks around a while), that will not be a good site. You could choose to plant asparagus in a raised bed, if that is your only site option.
Asparagus is sensitive to any competition from other plants, so remove all grass, weeds, and any other existing vegetation from the planting area, including roots. If the area you want to plant is quite weedy, and has been so for a while, consider taking next year to get the weed situation under control, and planting the following spring.
Asparagus likes rich, non-acidic soils. The last is usually easy to provide in Colorado, but the former requires some soil amendments. Loosen the soil to a depth of 6 or 8 inches over the entire planting area with a tiller or shovel. Spread 2 to 3 inches of compost or well-rotted manure over the planting area and mix it into the soil. If you want to protect the bare soil from weeds, mulch with leaves or weed-free straw. You are now done for the winter! Congratulations.
Come spring, you will need to order your plants online, or purchase from a local garden center. It’s best to get the varieties where the spears are all-male, as they are the most productive, since they do not spend any energy producing seeds.
Dig a trench 12 inches wide by 6 inches deep where the crowns are to be planted, keeping the rows about 2 feet apart. Plant crowns about 12 inches apart. Spread the roots and cover the crowns with two inches of rich soil, amended with compost or a slow release fertilizer. As the spears begin to grow, fill the trench with soil two inches at a time.
At this time, you need to muster patience - you just water and wait. One of the hardest parts of planting asparagus is to refrain from picking anything the first year. Newly planted crowns should be left to form "ferns," which provide food for the roots. The second spring after planting, a few shoots can be harvested, but just once or twice. Leave the rest to feed developing roots. The third year , however, is where your patience pays off, and you can harvest away!
Asparagus should be fertilized in the spring just before spears emerge and again right after the last harvest in June for older plantings. Use 1 to 1.5 pounds of an all-purpose garden fertilizer, such as 10-10-10, per 100 square feet.
Pull or carefully dig any weeds that come up in the beds to keep out competition.