If you are an asparagus lover, chances are good that you would like to include them in your garden. Many gardeners buy established bare root stock when growing asparagus but can you grow asparagus from seeds? If so, how do you grow asparagus from seed and what other information on asparagus seed propagation might be helpful?
Can You Grow Asparagus from Seeds?
Asparagus is often grown from bare root stock crowns. The reason for this is that growing asparagus requires patience. Crowns take three growing seasons before they are ready to be harvested! Even so, this is significantly faster than if you try growing asparagus from seeds. That said, yes, asparagus seed propagation is very possible and a little cheaper than buying crowns.
Asparagus seeds, or berries, turn bright red in autumn. Once the tops fall over, the tops can be collected and hung upside down in a warm, dry area for about a week or so to ripen. To catch the seeds once completely dried, keep a bowl beneath them or gently tie a brown paper bag around the tops when hanging. These seeds can then be used for planting asparagus. Likewise, you can purchase them from reputable suppliers.
How Do You Grow Asparagus from Seed?
Asparagus (Asparagus officinalis) is a hardy perennial suited to USDA zones 2-8 and is native to Western Europe. This perennial can remain viable for 10-20 years, so choose your garden site carefully. Asparagus needs a soil pH of between 7.0 and 7.2 in fertile, well-draining soil.
So how do you go about planting asparagus seeds? There’s no trick to growing asparagus from seeds, just be patient. It’s recommended that you start asparagus seeds indoors or in a greenhouse in mid-February to May under bright lighting. Soil temperatures for seed germination should be between 70-85 degrees F. (21-29 C.). Soak the seeds for a couple of hours, then plant each seed ½ deep in sterile soil in individual 2-inch pots. They should sprout anywhere between 2-8 weeks from planting asparagus seeds.
Seedlings are ready to transplant when they are 10-12 weeks old and all danger of frost in your area has passed. Space the transplants 18 inches apart in rows set 3-6 inches apart. If you want thinner spears, space the transplants 8-10 inches apart with the plant set 4 inches deep. If you like thicker spears, plant them 12-14 inches apart and set 6-8 inches deep. Consider planting your new asparagus babies near your tomatoes. Asparagus repels nematodes that attack tomato plants while tomatoes repel asparagus beetles. A very symbiotic relationship indeed.
As the plant grows, cover the crown with soil and keep it moist (one inch of water per week). Fertilize in the spring with 1-2 cups of complete organic fertilizer per 10 foot of row and dig in gently. Remember, don’t harvest the plant until its third year; allow the plant to set ferns and redirect its energy back into the plant. Cut the ferns down to 2 inches tall in the late fall.
In the plant’s third year, you can begin regularly harvesting the spears. The season usually lasts around 8-12 weeks. Cut the asparagus spears 1-2 inches below the ground and at least 2 inches above the crown using a sharp knife or asparagus harvesting tool.