If you’ve got the space for an asparagus patch you should definitely consider planting this amazing perennial vegetable. In the first few years it’s recommended to resist harvesting all but a few spears, but from then on the plants just keep on giving, cropping every spring for more than 20 years! Asparagus is best purchased as two year-old crowns, which are dormant root systems that look a bit like a muppet wig having a bad hair day. Crowns will produce spears earlier than plants grown directly from seed. To plant your crowns choose a sunny, well-drained spot, dig a trench about 75cm deep and scatter organic manure along the bottom of it. Make a mound of soil where you want to plant each crown and sit the roots on top of the mound like a wig. Space them about 40cm apart along the trench. Cover the crowns with about 5cm of soil, water them in, and wait to see some growth in spring. Gradually fill the trench as the plant grows ensuring the growing tips are not covered.
When the plants are mature enough to start harvesting spears cut them off below soil level when they are about 15-20cm long. In autumn spears will start to go yellow and they can be cut down to soil level. Top dress with manure and compost in late winter and keep perennial weeds out of the patch, as the asparagus does not like competition or having its roots disturbed. We have Mary Washington crowns for sale now in the nursery. This is a common, old fashioned variety that is resistant to fungal diseases and is a reliable, heavy cropper.