Repotting guide

When & how to repot Prickly Cycad (Encephalartos altensteinii)

Also called Prickly Cycad, Eastern Cape Cycad, Breadtree.

More about prickly cycad

About Prickly Cycad

Encephalartos altensteinii · also called Prickly Cycad, Eastern Cape Cycad · tropical

Encephalartos altensteinii is a large, slow-growing cycad native to the Eastern Cape and KwaZulu-Natal provinces of South Africa, where it grows in coastal thicket and bushveld on well-drained slopes. It is one of the longest-lived plants known — a specimen at Kew Gardens has been growing since 1775. The single most important care fact is that it must have perfectly drained soil and full sun; it is extremely slow-growing and resents disturbance. All parts of this plant are toxic to cats and dogs due to the presence of cycasin.

Mature size: 4–7 m (13–23 ft) tall with leaves to 2 m (6 ft) long in the wild; container specimens are usually under 2 m (6 ft).

How to tell prickly cycad needs repotting

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

Thick roots out of the drainage holes, or circling the surface and lifting the plant.
The pot dries out unusually fast and prickly cycad wilts between waterings it used to shrug off.
The plant is visibly top-heavy and tips over easily.
Stalled growth and small new leaves over a full season — though with a big specimen, top-dressing is often the better first response before a full repot.

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 cycad

Every 2–3 years; top-dress in the in-between years. Prickly Cycad's growth habit — upright, single-trunked cycad with a stout, rough-barked trunk and a terminal crown of stiff, dark-green, pinnate leaves with sharply spined leaflets. — sets the pace. Encephalartos altensteinii is a large, slow-growing cycad native to the Eastern Cape and KwaZulu-Natal provinces of South Africa, where it grows in coastal thicket and bushveld on well-drained slopes. It is one of the longest-lived plants known — a specimen at Kew Gardens has been growing since 1775. The single most important care fact is that it must have perfectly drained soil and full sun; it is extremely slow-growing and resents disturbance. All parts of this plant are toxic to cats and dogs due to the presence of cycasin.

What size pot to step prickly cycad up to

Move up exactly one pot size. A heavy prickly cycad dropped into a vastly bigger pot sits in a reservoir of wet soil its roots cannot reach, which rots them and destabilises the plant. In the years between repots, lift off and replace the top 3–5 cm of soil (top-dressing) instead — it refreshes nutrients without the shock of a full repot.

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 cycad

Early spring, just as new growth restarts, is the ideal window for prickly cycad. The plant is moving into its strongest growth phase and re-roots into fresh soil quickly. Avoid repotting in winter dormancy or, for flowering plants, while it is in bud or bloom — recovery is slowest then and you risk dropping the flowers.

Step-by-step: repotting prickly cycad

Consider top-dressing first. If prickly cycad is not badly root-bound, scrape off and replace the top 3–5 cm of soil instead — far less shock for a big plant that hates moving.
Get help and one size up. For a full repot, choose a pot just one size larger. A heavy plant needs two people and a stable, free-draining pot.
Ease it out on its side. Lay the plant down, slide the pot off, and gently loosen the outer roots. Do not bare-root a mature specimen.
Repot at the same depth. Add fresh coarse, free-draining sandy or gravelly mix beneath and around the rootball, keeping the original soil line. Firm it so the trunk is stable and upright.
Water and leave it put. Water thoroughly, then leave prickly cycad in the same spot and light — moving and repotting at once is what makes it drop leaves.

Aftercare

Leave prickly cycad in exactly the same spot and light it was in before — moving and repotting at the same time is what makes a big specimen drop leaves. Water it in well, then let the top of the soil dry before watering again so the larger volume of fresh soil does not stay sodden. Do not fertilise for about 4 weeks — fresh mix already carries nutrients and feeding freshly disturbed roots scorches them.

The right soil mix for prickly cycad

Prickly Cycad wants coarse, free-draining sandy or gravelly mix. Use a mix of coarse sand, perlite, and a small amount of loam (roughly 2:1:1) with a slightly acidic to neutral pH; avoid peat-based mixes that retain moisture. 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 cycad — frequently asked questions

How often should you repot prickly cycad?

Every 2–3 years; top-dress in the in-between years for prickly cycad. Fully repot prickly cycad only every 2–3 years; in the in-between years just top-dress the top 3–5 cm of soil. Step up one pot size in spring with coarse, free-draining sandy or gravelly mix. It is heavy and hates being moved, and a vastly oversized pot holds water against the roots and rots them.

What size pot does prickly cycad need?

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

Should you top-dress or fully repot prickly cycad?

For a big, heavy prickly cycad, top-dressing — replacing the top 3–5 cm of soil — is the gentler option most years, with a full repot only every 2–3 years. A mature specimen sulks and drops leaves when fully repotted, so do it as rarely as the roots allow.

Should you fertilise prickly cycad after repotting?

Not immediately. Wait about 4 weeks after repotting prickly cycad. Fresh mix already contains nutrients, and feeding freshly cut or disturbed roots burns them. Resume your normal feeding routine once you see new growth.