Mary Washington Asparagus Guide
Asparagus grows best in warmer weather between 55°F-85°F. They do OK in bigger containers and small gardens. Note: it will stay alive for upwards of 15 years so plan accordingly if using a container. Bank on Seeds recommends transplanting.
If Direct Seeding
- Direct seed outside 3-4 weeks after last frost date; or
- Direct seed into a container 20-25 inches deep and wide anytime of the year. It can be placed outside when the temperature is between 55°F-85°F; or
Begin the growing season early and start the asparagus seeds indoors in trays or pods 8-10 weeks before the last frost date; clingwrap the container to seal in the warmth. Germination is best and fastest between 70°F-80°F. It can be transplanted outside 12 weeks later.
Sow seeds 1/2 inch deep and 18 inches apart with rows spaced 36 inches apart. Germination will take 10-30 days. Thin seedlings to 12 inches apart when they start competing for space.
Asparagus likes a sunny spot but can tolerate a bit of shade and well-draining soil. Prepare the plot for the asparagus by digging a trench 12 inches into the ground. Place each transplant deep into these trenches 18 inches apart (if you have multiple rows, leave 2-3 feet of space in between) and shovel the soil back onto the plants being careful not to damage roots. 3-4 inches of the asparagus spear should be poking out when you are done.
Add a layer of mulch each year to reduce weeds and retain moisture. Water asparagus frequently when in the first 6 months then less often when it matures - this would be about an inch a week if there is no rain.
Asparagus is more suited to be grown outdoors but if you need to, a container at least 20 inches deep and wide is needed. Keeping the area around the plant free of weeds will help greatly with pests and other weeds that compete for nutrients and water. Mulch or add compost to the top once or twice a year or use a 10-10-10 fertilizer. Around 15-20 plants can continually feed a family of four.
Days to maturity take 2 years. Then every year after asparagus will regrow itself for another 15 years. Cleanly snip the tender green shoots off the asparagus when they reach 8 inches long. Asparagus can be eaten raw or cooked.
Resistant to rust
Asparagus beetles – usually can be hand picked and dropped in soapy water, neem oil
*Plant asparagus with tomatoes, basil, parsley, marigolds, and nasturtiums. Avoid planting with or near garlic, onions, and potatoes.*