Asparagus is the vegetable of kings, delicious especially picked fresh from the garden. It is best grown from 2 year old crowns, available from nurseries in Melbourne from June to September. Grown from seed or seedling you will be waiting several years for any asparagus worth eating. Plant from crowns for fastest results.
For the average family, plant 6 or more crowns. This will give you a decent serve of asparagus spears per week from anytime between August and October.
Site and Soil Preparation:
- pH 6 – 7
- Asparagus likes cold winters but will also tolerate salt-laden winds of coastal areas.
- Asparagus should be given a dedicated space as they can last and produce up to 20 years. They are herbaceous, meaning they will go into dormancy over winter, only to see new spears poking their heads again above the mulch by late winter.
- Before planting, dig a trench for the crowns, enriching the soil by adding copious amounts of well-rotted manures and composts.
- Dig a trench 1.2m wide. This will accommodate two rows of crowns. Plant each crown 45-50cm apart in each trench. Make each trench about 20cm deep.
- Raise the soil within the trench into mounds, so that the crown roots can be spread over the mound. Cover with soil so that there is about 8cm of soil over the top of the crown. If they are too deep, you will get fat spears but fewer of them. Too shallow and you will get lots of thinner spears. By the start of spring you will start to see the spears poking up through the soil.
- Mulch well with a feeding mulch, such as lucerne, pea straw or sugarcane mulch.
Caring for Asparagus
- Asparagus responds well to watering and can cope with lots of it. Ensure drainage is good otherwise the fleshy roots will rot.
- When your asparagus plants are 4 years old (ie 2 years after planting crowns) you can start to pick a few spears from each plant. Up until then resist the temptation to harvest the asparagus. You should allow the spears to just grow taller and taller as they develop into feathery fronds. These die back in autumn, putting nourishment back into the crowns. This will ensure crops in future years.
- When your asparagus crowns are 5 years old and more, you can harvest as many spears as you can eat, for 6-8 weeks. Leave the rest to develop otherwise you will exhaust the crowns for future years.
- Allow any that are thinner than pencil thickness to develop and mature to frond stage.
- Optimum picking height is at a maximum of 25cm. Use a sharp knife to cut the spears 3-5cm BELOW the soil surface.
- In autumn, before dormancy when the feathery fronds turn brown, apply a layer of well rotted manures and water with seaweed tonic regularly. Top up the layer of mulch at this time too.
- Cut the feathery stalks back down to about 3cm once they have turned brown.
- In early spring, add some pelletized fertiliser manure at the rate of about 60g per square metre of soil area and water in well. This will help feed the asparagus through its harvesting period.
Poorly Producing Asparagus may be due to lack of nutrition, over- or under-watering, harvesting for too long the previous year, or the crowns have become too old and need dividing.
Asparagus crown ready for planting. This has had 2 years of growth from seed.
Not all asparagus points upwards! Harvest the spears when they are at about 25cm tall.
Ready for anything - risotto, grilled, frittata...
After 2 months of harvesting, leave any more spears to develop into asparagus fern. It dies back to feed the root system, to ensure many years of asparagus for you.