How to grow Hamburg Parsley

Where to plant

Grow Hamburg parsley in full sun or part shade in deep, loose, fertile soil that stays moist but drains well. Stony or heavy, compacted soil gives short, forked roots, so it is worth loosening the bed deeply or growing it in a raised bed.

It needs about four months of cool growth. Seed sown into summer heat germinates poorly, and the roots need the whole season to size up.

• The Northeast, Midwest, Northern Plains, Mountain West and Alaska: sow in spring as soon as the soil can be worked. Summer sowings do not mature before the ground freezes.
• The Mid-Atlantic and Southern Plains: sow in March or April.
• The Mid-South: sow in March or April, or in August or September for roots to dig through winter.
• The Pacific Northwest: sow from March to May. Roots can stay in the ground through the mild winter.
• Florida, the Gulf South, Texas, the Desert Southwest and California: sow in fall, roughly August to November, so the roots grow through the cool, mild months.

How to plant

1. Soak the seed overnight to help it germinate. Like all parsley, it sprouts slowly and unevenly, especially in cold, wet soil.
2. Sow directly where it is to grow, as it dislikes being transplanted. Cover the seed no deeper than 1/4 inch (6 mm).
3. Keep the row evenly moist until seedlings appear, which can take several weeks.
4. Thin seedlings to about 6 to 8 inches apart so the roots have room to swell.

Watering and feeding

Keep the soil evenly moist through the season. Dry spells slow the roots, and sudden heavy watering after a dry spell can split them. Work compost into the bed before sowing; heavy feeding is not needed.

Pruning and care through the year

• Keep the row weeded while seedlings are small, as they grow slowly at first.
• Hamburg parsley is a biennial grown as an annual. If it overwinters and flowers in its second year, the leaves turn poor and the root becomes woody, so dig it before then.

Harvesting

Dig the roots in late fall, about four months after sowing. The roots are frost resistant, and RHS notes that the largest roots taste best. In mild areas you can leave them in the ground and dig as needed through early winter; in cold areas, mulch the row or lift and store the roots.

Pick a few leaves as you need them through the season and use them like flat-leaf parsley, but do not strip the plants, as the leaves feed the root.

Using it

The roots are sweetest cooked. Add them to soups and stews, roast them with other root vegetables, or mash them. Both the leaves and roots keep their flavor when dried.