Asparagus is easy to grow, producing new shoots from mid-spring to early summer – a hungry gap delight to be savoured. These large perennial plants need to be grown in the ground where they will crop annually for many years. However, new plants take a couple of years to settle in before you can start harvesting, so patience is required.
I use a rating system to help me decide what to grow and it considers lots of factors, but the main ones are: how tasty it is, how healthy it is to eat, how expensive it is to buy, how big it's harvest is, when it's harvest period is and whether I can buy it organically and if not how much it's sprayed by commercial growers.
Asparagus doesn’t score particularly well in this system, like many perennials, because it’s in the ground all year round, but has a relatively short harvest period. It earns it’s place in the garden though because it’s fairly easy to grow and it provides it’s delicious harvest when we need it most, all through the hungry gap.
We’ve also found that it lends itself to interplanting too, which helps considerably with the harvest value.
Asparagus is a valuable crop because of it’s availability in spring, I’d grow about 0.5m2 per person myself, this will give you a couple of meals a week.
Asparagus must be grown in slightly alkaline soil, directly the ground, in well drained soil, with a thick mulch of organic matter and few weeds. It’s extremely deep rooted, so it’s good crop to grow if watering is an issue.
Asparagus is normally planted from crowns, which are usually one or two years old. These crowns are left for 2 years to establish themselves, without any harvesting. In the third year harvest lightly for six weeks (usually from mid-April until the start of June).
Plants grow tall, from 6-8ft and they create a lot of shade, so bear that in mind when choosing where to plant them. In October they start to die back and they are usually cut back to the ground in November. During this growing period they store considerable resources in the roots, allowing them to grow extremely quickly in the following spring.
It is best to choose an all-male cultivar, as these tend to produce better and stronger spears. Non-hybrid seeds produce female as well as male plants, and these will in turn produce seedlings that will need to be weeded out to prevent competition with the existing plants
We don’t grow multiple successions of asparagus, however you can choose different varieties that crop at slightly earlier or later than others, for an extended harvest period.
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We don’t have sufficient experience to recommend specific varieties, but the RHS has some good recommendations.