So, asparagus! Choosing to grow asparagus from seed rather than buying the crowns pays off in the cost department, but you get hit with extra waiting time as compensation. A full extra year, in fact. On the other hand, if you really, really like asparagus, that wait might be worth it- plant a whole packet of seeds, and you could very well end up with 75 to 100 producing crowns as a reward for your patience!
(Disclaimer: Starting an entire packet of asparagus seeds may not be the wisest choice unless you really, really like asparagus. And have the space to plant all those crowns. So many crowns.)
Plan to start your seeds indoors at least 2-3 months before your last estimated frost date. For my area, zone 7a, the estimated last frost date is April 15th- so I start my asparagus seeds anywhere between January 15th to February 15th. You really want to start them extremely early- asparagus seeds can take up to a full month to germinate after planting!
When you’re ready to start your asparagus, start soaking the seeds in a glass jar of water a day before you want to plant them. Some say this is an optional step and you can just go ahead and plant the seeds, but I have yet to test this. The seeds are poisonous, so don’t eat them!
Place the jar somewhere safe to soak for the next 24 hours. Learn from my mistakes- if you, too, have curious pets that possess no sense of self-preservation whatsoever, place the jar somewhere where nosy creatures can’t knock it over, stick their paws in the jar, or try to drink the water.
Once the 24 hours are up, retrieve your jar and separate your seeds from the water. Using your finger, gently poke little 1/2 inch holes in a pot of soil (make sure you have drainage holes!), dropping a seed in each one. Cover the seeds with dirt, firming the surface with your fingers, and water. Cover the whole thing with a greenhouse lid (or plastic wrap, in a pinch!), and place in the light.
The general estimate for how long it takes asparagus seeds to germinate is 21 days to a full month, but this number isn’t a hard rule. Warmth can speed germination considerably- in the warm room I grow all my seeds in, I had my first asparagus seed germinate in 12 days. The temperature of the room stayed roughly 75 degrees Fahrenheit during the day, dipping down to mid-60s at night. The pots were kept under grow lights for at least 12 hours a day.
Asparagus sprouts are very spindly and delicate looking. Keep your lights hanging close enough to the seedlings to prevent stretching! I turn a low-running fan on my seedlings at times to try and get them a bit more used to dealing with the wind while they’re little.
Nurse your little ferny seedlings indoors all through the cold, transplanting outside to a temporary bed only once all possible risk of frost has passed completely. Make sure the bed has plenty of rich soil, mixing in a good amount of compost. Asparagus also isn’t fond of acidic soil, so if you’ve got low pH, you may want to try and skew it a bit more towards neutral before sticking your asparagus seedlings out in the garden.
When transplanting, space these young seedlings at least 6 inches apart from each other for now- you’ll be digging them up in the next year or so to transplant them to a permanent, final location then!