HAMBURG parsley is one of those vegetables that you’ll find in most seed catalogues, but not on many allotments.

I’m told it’s popular among Czechs and, as the name suggests, in some parts of Germany. You’ll also find it listed as Berliner parsley, or root parsley. It is in fact simply a variety of ordinary parsley, which has been bred for its edible roots rather than its foliage.

Catalogues often trumpet it as a dual-purpose vegetable, suggesting that you should eat the leaves as parsley during the growing season and then dig up the roots as a winter crop.

I’m unconvinced. Surely denuding the plant of its photosynthesising foliage as it grows will reduce the amount of root produced? And besides, I find Hamburg parsley leaves quite inferior to ordinary parsley.

So let’s concentrate on the white root, which, when grown successfully, tends to be about the size and shape of a carrot. I say “tends” because there’s quite a variation in size and shape available but seed packets often don’t specify which cultivar they contain, simply naming it “Hamburg parsley.” If you shop around, though, especially online, you can find named cultivars, with accurate descriptions of what to expect.

Like all parsleys, Hamburg can be erratic in germination, especially if the seed isn’t very fresh, so I prefer to sow in cells or modules, in gentle warmth, in February or March.

As soon as the seedlings’ roots have filled the cell, I plant them out into the open ground at about 9 inches apart. However, you can also sow directly into the soil in shallow drills in spring and gradually thin out the seedlings that appear. They can also be grown quite successfully in large pots.

Watering and weeding are the only attention that Hamburg needs during the summer, and mulching with compost will reduce the workload in both cases.

The roots can be lifted in the autumn but will usually survive winter left where they are. Although they’ll store safely in a box of damp sand in a shed or garage, there’s no doubt the flavour is much stronger when they’re taken straight from the garden.

The only big problem I’ve ever had with Hamburg parsley is the disease called “parsnip canker.” In a bad year, I’ve lost an entire crop to this colourful fungal rot. There are no treatments for parsnip canker but researchers have identified a few tricks to help prevent it.

Early sowings are said to be most susceptible, as are large roots, so it might be worth leaving the seedlings at half the recommended spacing to end up with smaller specimens. Poorly drained soil is thought to be a key factor, so it’s best to grow Hamburg in ground with plenty of compost or manure in it.

Assuming you get past the dreaded canker, you’ll have a nutty-tasting root, with hints in its flavour of parsley and parsnip. It doesn’t need peeling and is lovely raw, roasted or used in soup.