Repotting guide

When & how to repot Prickly Saltwort (Salsola kali)

Also called Prickly saltwort, Prickly glasswort, Russian thistle (when a tumbleweed), Common saltwort.

More about prickly saltwort

About Prickly Saltwort

Salsola kali · also called Prickly saltwort, Prickly glasswort · edible

Salsola kali is a spiny, bushy annual in the amaranth family (Amaranthaceae) that colonises sandy beaches, strandlines, and coastal dunes from Europe's Atlantic and Baltic shores to Mediterranean coastlines, and is naturalised across North America as a common tumbleweed. It is highly salt-tolerant, drought-resistant, and adapted to nutrient-poor, well-drained sandy soils in full sun. Young shoots before the spines harden were historically eaten as a salted vegetable and the plant was once an important source of soda ash for glassmaking. Due to potential accumulation of oxalates and nitrates, it should be treated as mildly toxic to pets.

Mature size: 30–100 cm tall, 30–80 cm wide

How to tell prickly saltwort needs repotting

Repotting on a calendar is less reliable than reading the plant. For prickly saltwort, watch for these signs:

Roots circling the bottom of the module or pot, or poking out of the drainage holes.
The seedling dries out within a day and growth has visibly stalled.
Roots are white and matted in a tight spiral when you tip the plant out.
It has outgrown its current container for the stage of the season — pot prickly saltwort on before it becomes hard root-bound.

For the underlying biology of a pot-bound root system and why it stalls a plant, see our guide to spotting and fixing a root-bound plant.

How often to repot prickly saltwort

Pot on seedlings as they grow; not a perennial repot. Prickly Saltwortis grown for one season, so the question is really “how often to pot on” — keep moving it up before the roots circle. Erect to spreading, much-branched annual herb with stiff, prickle-tipped leaves; breaks off at the base at maturity and rolls as a tumbleweed dispersing seed..

What size pot to step prickly saltwort up to

Pot prickly saltwort on gradually — a seedling jumped straight into a huge pot sits in cold, wet, airless soil and stalls. Step up one or two sizes at a time as the roots fill each container, finishing in a large final pot or the ground. The aim is roots that never circle and never check.

Not sure of the exact diameter? Our pot size calculator takes the current pot and root spread and tells you the right next size — it deliberately recommends a single step up, never a big jump.

The best time of year to repot prickly saltwort

Pot prickly saltwort on through the active growing season, whenever roots fill the current container — there is no single date, just "before it becomes root-bound". Avoid potting on during a cold snap.

Step-by-step: repotting prickly saltwort

Pot on before it is root-bound. Check prickly saltwort regularly; move it up as soon as roots reach the edge of the cell or pot, not after they have circled.
Step up one or two sizes. Choose the next container up — not a giant one. Cold, wet, unused soil around a small root system stalls seedlings.
Knock it out gently. Support the stem, tip the pot, and ease the rootball out without breaking it. A little teasing of circled roots at the base is fine.
Pot into rich mix. Set it into fresh sandy, saline-tolerant, well-drained, alkaline at the same depth (tomatoes are the exception — they can go deeper to root along the stem).
Water in and grow on. Water well, keep it in good light, and resume feeding once it is established and growing again.

Aftercare

Water prickly saltwort in well and keep it in bright light; a freshly potted-on seedling can wilt for a day while roots settle, so do not overcompensate by drowning it. Do not fertilise for about 1 week — fresh mix already carries nutrients and feeding freshly disturbed roots scorches them.

The right soil mix for prickly saltwort

Prickly Saltwort wants sandy, saline-tolerant, well-drained, alkaline. Thrives in light, nutrient-poor sand or gravel with a neutral to highly alkaline pH, and tolerates high salt concentrations that would kill most plants. Avoid clay or moisture-retentive soils. Always use fresh mix when you repot — reusing old, broken-down soil reintroduces the compaction and poor drainage you are repotting to fix.

Repotting prickly saltwort — frequently asked questions

How often should you repot prickly saltwort?

Pot on seedlings as they grow; not a perennial repot for prickly saltwort. Prickly Saltwort is a seasonal crop, so you pot it on as a growing plant rather than repotting a perennial. Step seedlings up gradually into sandy, saline-tolerant, well-drained, alkaline so the roots never circle the cell, ending in a large final container. A root-bound transplant stalls and never fully recovers.

What size pot does prickly saltwort need?

When is the best time of year to repot prickly saltwort?

Can you put prickly saltwort straight into a much bigger pot?

No. Even a fast-growing prickly saltwort should only go up one pot size at a time. A vastly oversized pot holds a reservoir of wet soil the roots cannot reach, which stays cold and soggy and rots the roots — the opposite of what you wanted.

Should you fertilise prickly saltwort after repotting?

Not immediately. Wait about 1 week after repotting prickly saltwort. Fresh mix already contains nutrients, and feeding freshly cut or disturbed roots burns them. Resume your normal feeding routine once you see new growth.