Truth is, every gardener (and even people who don’t enjoy gardening) should grow asparagus. It is one of the easiest vegetables to grow, most people like to eat it, and it regrows all by itself, year after year. It can be a little finnicky to establish, so I’ll give you some tips on how to grow asparagus.
Asparagus is a perennial vegetable, my favorite. No replanting every year, this veggie will happily grow for many years. It takes three years for Asparagus to establish properly. You might get a small harvest in the second year, but full harvest won’t be until the third.
I like to start my Asparagus from seed, but I’ve started them from crowns as well. Mary Washington has been the best performer for me, and that’s what I’ll stay with from now on, but the purple varieties came out quite well also, and they’re really nice-tasting.
The main differences between Asparagus grown from seed and those grown from crowns is the time it takes to harvest, and the adaptability of the plant itself. From seed, it takes 4 years before you’ll have a good harvest. From crowns, it takes as short as a year.
My main reason for growing them from seed, is that I have found seed-grown plants to be stronger and they adapt better to their surroundings. This doesn’t just apply to Asparagus actually, I find it to be so with most other fruit or vegetable plants as well. I’ve chosen to grow some grafted varieties of fruit trees, mainly for the quality of the fruit, but the seed grown varieties are hardier, need less water, are less susceptible to heat or cold stress, and so on.
Asparagus is easy to grow from seed. I like to soak them in a little bit of warm water overnight, then plant them out in well-draining seed-raising mix, only planting them as deep as the thickest part of the seed. Within days (2 weeks max) you’ll see a little shoot. This shoot won’t stay little for long, they’re exceptionally fast growing!
Asparagus plants will be productive for 15-20 years, so make sure you plant them in the right spot where they can stay. They do NOT appreciate being moved!
I like to start my seed in small pots, then plant them out. If you’re sowing them straight into the ground, plant them in trenches or deep furrows. The crowns need to be below the surface of the soil once they’re fully grown, which is hard to achieve if you sow them at soil-level. Asparagus sends roots out from the crown, which looks like a great big brown spider with many, many legs. These roots and the crown need to be under the soil, where it’s moist and dark.
Same applies for when you buy crowns instead of seeds. Plant the crown on a furrow and make sure the crown is fully covered with soil. The furrow is like a raised little bed for the centre of the crown, so the roots can snake down from it. Kind of like a seat for its bottom, with its legs hanging down.
If you do buy them as crowns, give them a good soak before you plant them. You can add a little seaweed solution to strengthen them. Plant them 2-3 feet apart. Make sure you plant them the right way up. Sounds really silly, but it can actually be a bit tricky to tell, because they have dry stalk from last season, and they can look like roots. The easiest way is to hold the crown in your hand, and see which way the long roots fall most naturally.
Where to Grow Asparagus
Again, remember Asparagus is a perennial, permanent vegetable. It can’t be transplanted once it has established itself, so make sure you choose the right spot for it.
It will grow in most ordinary gardens, as long as your soil is well-draining. If your soil is high in clay, or doesn’t drain well, enrich it first with gypsum or lime, compost, sand, and mulch. Asparagus prefers shelter from strong winds. It copes well with hot sun, but make sure it’s well-mulched to keep the moisture at soil level. They appreciate regular watering.
Asparagus needs your soil to be fairly loose. If you’re a no-tiller, prepare your bed beforehand with piles of manure and mulch, to decompose and provide great soil for the Asparagus. If you’re not against digging – dig! Dig the soil, dig manure and organic matter through, and make it nice and loose for Asparagus’ roots to go forth and conquer. You’ll want loose soil at least 16 inches deep.
Asparagus loves food! Fertilize regularly, or grow in conjunction with Comfrey, which provides you with free green mulch (high in nitrogen!) to cut and mulch around the Asparagus plants. These two grow well together, as Comfrey’s roots unlock nitrogen, which is then available for the Asparagus to use. It also doesn’t grow too tall, so won’t compete for sun with Asparagus.
You’ll need to fertilize at least twice a year, depending on the type of fertilizer you’re using. Give them a good dose of vegetable fertilizer. I love Dr. Earth‘s range of fertilizers. Once you’ve harvested your crop, give them a heap of rotted manure, and make sure the mulch cover is still growing strong. If it isn’t, reapply!
You can harvest your first small crop in the second year (if grown from crown). Cut two or three stalks from each plant, but don’t cut too many. Leave the rest of the plant to grow up so they turn into nice big fern-like plants.
I lost a whole crop a few years back, so I’ve since adopted a different method of harvest. I used to have no particular method at all, just snap it and often eat it right there and then. Once I researched why I lost them (appears to be a combination of rust and my gung-ho method of chopping), I found out that you need to be a little delicate when you cut them. There is an embryo shoot inside, and it is easily destroyed which leads to the crown dying.
Follow the stalk all the way down, with two fingers, right down into the soil, and gently pull outwards, away from the crown. It will snap all by itself, at the perfect place! If you need to cut lots of plants this is not an effective method. My kids love to help me with harvesting, so I’ve since bought a special Asparagus knife to use. It’s the same kind of tool you’d use for Dandelion roots.
The tops of the Asparagus plants will start to die off in the fall. Cut them off, and mulch the plants well, once again. You might want to consider burning the dead stalks, or putting them in a plastic bag and tossing them in the trash immediately, rather than composting them. Asparagus is susceptible to rust and it can help prevent spread.
I’m not a huge fan of this, too much work for not much outcome, I say, but some people (my mom and dad for example) love them. I guess they’re a bit of a delicacy. If you want white asparagus, you’ll need to keep the soil around the sprouts piled up. Create hills around the stalks to prevent the light from reaching them, which results in white asparagus stalks. You’ll need to hill up at least once a week, right throughout the harvest season. This can take 6-8 weeks. Don’t forget to take the hills down once your harvest is finished.
Asparagus is actually pretty good, disease-wise. It’s not a fragile little flower and won’t cave in at the drop of a hat. But, as I mentioned above, rust sucks. It really does.
Rust is easily identified, it looks like it sounds; rusty. It attacks all plants, young and old, and it doesn’t look good at all. It’s a fungal disease, and burning the old stems is a great way of preventing the spread of fungi. Once you have rust in your plants, you can try anti-fungal spray, but I have not had a lot of luck with it. After my failed harvest, an old farming neighbour told me his mother used to add ashes to the soil once a year for prevention. I’ve since applied ashes every year and rust has not happened again. Whether this is science or luck, not sure, but I’ll use ashes every year, just to be sure.
Another attack may come in the way of the asparagus beetle. It’s pretty cool looking, not cool to have. It lays eggs on your new juicy shoots in small holes. They can affect the crown itself too.
Once you see one, you’ll see a 1000! They seem to come out of nowhere. Chickens are the best pest control for these guys, your girls have a great time scurrying around and pecking their little hearts out. If you don’t have chickens, you’ll need to resort to another form of pest control, possibly in the way of neem sprays.