How to Grow Salsify in Australia

Salsify (Tragopogon porrifolius) is a biennial in the daisy family, Asteraceae, grown for the long, creamy white taproot it forms in its first year. Cooked, the root has a delicate, oyster-like flavour, hence the name oyster plant, and it is rarely seen in shops. It is grown much like parsnip and asks for little care, but it needs deep, stone-free soil and fresh seed.

Three mistakes that matter

1. Sowing into shallow, stony or freshly manured soil. The taproot can reach 30 cm, and stones, compaction or fresh manure make it fork and branch. Loosen the bed deeply, pick out stones and use only well-rotted compost, as set out in Site, soil and setup.
2. Sowing old seed into a dry drill. Salsify seed loses its viability quickly, and germination is slow even when it is fresh. Buy seed for the season you sow, and keep the drill moist for the two to three weeks it takes.
3. Letting plants flower and seed. Salsify grows wild along roadsides and in pasture across southern and eastern Australia. Its seeds blow away on fluffy heads like a dandelion's, so cut every flower stem before the heads open.

When to plant

Salsify is a cool-season crop that germinates in soil between 10°C and 30°C. Most zones have a spring window and an autumn window. It is slow, taking 14 to 21 weeks to form a usable root, so one sowing per window is enough for most households. The roots are frost hardy, which suits cold districts.

In southern gardens, an autumn sowing made by Anzac Day grows through winter and can be dug into spring. Avoid sowing in the hottest months, when a drying seedbed can stop germination.

Site, soil and setup

Pick the spot with the deepest, loosest soil in the vegie patch. Salsify stays in the ground for many months, so a bed that is dug well once pays off for the whole crop.

On heavy clay, a raised bed filled with a free-draining loam gives the roots the depth they need. Rake the surface fine before sowing, so the small drills stay even.

Sowing Seeds

Sow salsify direct where it is to grow, because transplanted seedlings tend to fork.

Salsify or scorzonera

Check the botanical name on the packet before you sow. Salsify has creamy white roots and lilac to purple flowers. Scorzonera, or black salsify (Scorzonera hispanica), is a different plant with black-skinned roots and yellow flowers, though it is grown in much the same way.

Sowing direct

• Water the base of a drill 10 to 15 mm deep, then sow the seed thinly and cover it.
• Space rows about 30 cm apart, or sow two or three seeds every 10 cm along the drill.
• Keep the surface moist with a fine spray; seedlings usually appear in two to three weeks.
• Mark the row clearly, because the seedlings have narrow, grass-like leaves that are easily mistaken for weeds.

Germination is slow and often uneven, so a patchy row after a fortnight is no cause to resow. Wait a full four weeks, then fill any gaps with fresh seed. The direct sowing guide covers drills and seedbeds in more detail.

Care by growth stage

Steady moisture and weed-free soil decide the root, and salsify needs little feeding in a well-prepared bed. Weeks count from sowing, and cold weather slows every stage.

Hoe between the rows but pull weeds by hand close to the plants, because a hoe blade can nick the top of the root. If growth stalls in poor soil, a light dose of all-purpose controlled release granular (NPK around 14-5-10) scratched in at the label rate can help.

Thinning

Crowded salsify makes thin roots, so thinning matters more than feeding. Do it early, while the roots are still short.

• Thin once the seedlings stand about 5 cm tall.
• Leave one seedling every 10 to 15 cm, keeping the strongest.
• Where seeds were sown in groups, keep one per group and remove the rest.
• Firm the soil back around the plants that stay.
• Add the tender thinnings to salads, as the young leaves are edible.

Companion planting

Salsify grows slowly, so the best partners are quick crops, or crops that never shade it.

Grows well with

• Lettuce and spinach, which are cut and gone long before the salsify roots fill.
• Leeks, another slow, upright crop with a similar season in the bed.
• Carrots, which share the same deep, stone-free preparation.

Keep the rows open to the sun and within easy reach for hand weeding.

Keep apart

• Pumpkins and zucchini, whose sprawling leaves smother and shade slow salsify rows.
• Corn and other tall crops on the north side of the bed, which cast shade for months.

Harvesting Roots

Start digging 14 to 21 weeks from sowing, once a test root is about 1.5 cm across at the top. Finish before plants run up to flower in spring. Where the ground freezes hard or waterlogs in winter, lift the whole crop in late autumn instead.

• Loosen the soil beside the row with a garden fork first.
• Lever each root up gently; never pull on the leaves.
• Handle roots with care, because they snap easily and bleed if cut.
• Dig only what you need, and leave the rest in the ground under a straw mulch through winter.
• Cut the leaves off about 2.5 cm above the root.

Roots keep best cold and humid. Store unwashed, topped roots in a perforated bag in the fridge crisper, or in a box of sand somewhere cool and frost free. Commercial cold stores hold them near 0°C for two to four months.

Raw roots ooze a sticky latex when peeled, so scrub them, steam or boil them whole, then slip the skins off. Roast, mash or add them to soups and stews.

Common problems

Forked or branched roots. Stones, compacted soil, fresh manure or a transplanted seedling, as in Three mistakes; prepare the bed as in Site, soil and setup.

Split roots. Soil that swings from dry to soaked makes the swelling root crack, so keep moisture even and mulch the bed.

Tough, fibrous roots. Long dry spells while the root fills leave it stringy, so water deeply before the soil dries out.

Short, thin roots. Crowded rows, shallow soil or an early dig; thin as in Thinning, and lift one test root before the main harvest.

Patchy or no germination. Old seed, a dry drill or soil outside 10°C to 30°C. Read more

A flower stem in the first season. Drought stress can push plants to bolt (flower early), and the root then stops filling out; water in dry spells and dig bolted plants promptly.

Pests and diseases

Salsify has few serious pests, and the main losses happen while the seedlings are small.

Snails and slugs (Gastropoda). They feed at night and after rain, eating seedlings down to the ground and leaving silvery trails. Hunt them by torchlight about two hours after dark, or use an iron-based bait. Read more

Cutworms (Agrotis species). These plump, greasy caterpillars of night-flying moths, the bogong moth among them, chew through young stems at soil level. Scratch the soil beside cut plants to find and remove them. Read more

Aphids (Aphididae). Small, soft green or black insects cluster on the leaves, sucking sap and leaving sticky honeydew. Hose them off with a strong jet of water, or spray insecticidal soap under the leaves. Read more

Prevention first

• Check seedlings at dusk for snails, slugs and cut stems.
• Clear weeds around the bed before sowing, because cutworms move from weeds onto young seedlings.
• Turn a few leaves each week for aphid colonies.
• Rotate beds as in Site, soil and setup.

Tips

1. Wait for a frost or two before the main dig in cold districts, because frost can sweeten the roots.
2. For spring shoots, leave a few roots in the ground and cut the old leaves back to 2.5 cm in early spring. Mound 10 to 15 cm of soil over the regrowth, then cut the pale shoots as they push through and cook them like asparagus.
3. Steam or saute the flower buds of any plant that runs up in spring, picking them before they open so no seed forms.