THE best time to plant an asparagus bed is three years ago, the old saying has it, because the wait is about that long before you get a full crop. The good news is that once it starts cropping it should keep going at full strength for at least a decade, and can still be productive 20 years on.

In Britain it is traditional to stop cutting asparagus around June 21, giving the plants the rest of the year to recover their strength ready for next season. You get around six to eight weeks of harvest annually, starting in April, at a time when the garden isn’t producing much else except puddles. I think it’s that, as much as the supermarket price, which makes asparagus seem so luxurious, more so perhaps than anything else on the vegetable patch.

I’ve planted a few asparagus beds over the years, and some have been great successes while others have been equally impressive failures. Unfortunately, the rules don’t always help.

For instance, it’s well-known that good drainage is paramount for this plant, but the best asparagus I’ve ever grown was on a heavy clay allotment which used to flood every year. The asparagus bed would sit underwater for a couple of days, but the spears those plants offered up were the thickest, tastiest and most plentiful I’ve ever seen.

It’s because setting up a whole new bed of asparagus can be chancy, after a significant investment of time, money and garden space, that I’ve taken to sowing seeds every year. Not only is this much cheaper than starting with spring-planted crowns, the usual method, but it also means that I’ve always got some new plants in the pipeline to replace any that don’t do well.

Most seed catalogues list a choice of asparagus varieties. I use Connover’s Colossal, a 19th-century type still popular for its exceptional flavour. You can sow the seeds indoors from February to April, or in the garden in April for transplanting the following spring. I like to start them in cellular trays, one seed per cell, in March. A place on a light windowsill in a reasonably warm room is all that’s needed.

The seedlings can sometimes take a few weeks to appear. Once they’re big enough to handle without squashing them, transfer each seedling to a 4” (10 cm) pot full of multipurpose compost. There are two different ideas about what to do next. Some people, after gradually acclimatising the young plants to outdoor conditions, plant them in their final positions during June of the same year or else the following spring.

I prefer to keep them in pots on a patio or steps for a year or two, moving them on to larger containers whenever their roots start showing through the bottom of their current pot. This means they are well-established, less vulnerable plants by the time I put them in their permanent place, either in the ground or in a large, 50-litre tub.