Repotting guide

When & how to repot Afghan Iris (Iris cycloglossa)

Also called Afghan iris, Round-tongued iris.

More about afghan iris

About Afghan Iris

Iris cycloglossa · also called Afghan iris, Round-tongued iris · flowering

Iris cycloglossa is a rare Juno-group iris endemic to Afghanistan, producing pale lilac to violet flowers with a distinctive circular fall in spring. Like other Juno irises it carries fleshy storage roots radiating from the base of the bulb, which must be preserved at planting and division. It demands excellent drainage, full sun, and a completely dry summer rest period — conditions that are difficult to achieve outdoors in wet temperate climates without glass protection. Toxic to cats and dogs.

Mature size: 25–35 cm (10–14 in) tall in flower; bulb clumps spread slowly to 10–12 cm (4–5 in).

Watch for — Fleshy root damage at planting: The storage roots radiate outward and are extremely brittle; snapping them at planting significantly reduces the plant's vigour or prevents flowering entirely. Handle bulbs as if they were eggs and plant in a wide hole.

How to tell afghan iris needs repotting

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

Roots growing out of the drainage holes, or the rootball lifting the plant proud of the rim.
Soil that has shrunk away from the pot sides and no longer holds water.
The pot is unstable because the plant has grown top-heavy.
Old, compacted, broken-down mix that stays wet too long — for a succulent that is a rot risk, so refresh it even if the pot size is fine.

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 afghan iris

Every 2–3 years, into bone-dry mix. Afghan Iris's growth habit — upright, bulbous juno iris with broad, channelled, glossy green leaves carried alternately up the stem; fully dormant in summer. — sets the pace. Iris cycloglossa is a rare Juno-group iris endemic to Afghanistan, producing pale lilac to violet flowers with a distinctive circular fall in spring. Like other Juno irises it carries fleshy storage roots radiating from the base of the bulb, which must be preserved at planting and division. It demands excellent drainage, full sun, and a completely dry summer rest period — conditions that are difficult to achieve outdoors in wet temperate climates without glass protection. Toxic to cats and dogs.

What size pot to step afghan iris up to

Use a pot only one size up — or even the same pot with fresh gritty mix if the roots have room. Afghan Iris stores water and rots in a large pot of slow-drying soil. A tight terracotta pot that dries fast is far safer than a generous plastic one. Never up-pot a succulent by several sizes.

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 afghan iris

Spring or summer, while afghan iris is in active growth and warm, is best — roots recover fastest then, and the plant is not sitting in cool damp soil. Avoid repotting a succulent in winter dormancy.

Step-by-step: repotting afghan iris

Repot dry. Do not water afghan iris for several days first. Working with dry roots and dry mix dramatically lowers the rot risk for a succulent.
Pick a snug, fast-draining pot. Choose terracotta one size up at most, with a drainage hole. Have gritty very sharply drained, alkaline gritty loam ready.
Tip it out and clean the roots. Slide the plant out, crumble off the old soil, and trim any black, mushy or dead roots with clean snips.
Pot into dry mix. Set afghan iris at its original depth in dry gritty mix, firming gently. Do not bury the stem deeper than it was.
Wait a week before watering. Leave it completely dry and out of harsh sun for about 7 days so any damaged roots callus. Only then water lightly.

Aftercare

Keep afghan iris completely dry and out of fierce sun for about a week so any nicked roots callus before they meet moisture; watering a freshly repotted succulent is the classic way to rot it. Then resume the normal lean, dry rhythm. Do not fertilise for about 3 weeks — fresh mix already carries nutrients and feeding freshly disturbed roots scorches them.

The right soil mix for afghan iris

Afghan Iris wants very sharply drained, alkaline gritty loam. A compost of equal parts loam, coarse grit, and leaf mould with added limestone chips to raise pH above 7.0 suits this species best. Avoid any compost that retains moisture around the bulb. Always use fresh mix when you repot — reusing old, broken-down soil reintroduces the compaction and poor drainage you are repotting to fix.

Repotting afghan iris — frequently asked questions

How often should you repot afghan iris?

Every 2–3 years, into bone-dry mix for afghan iris. Repot afghan iris every 2–3 years into a snug pot of very sharply drained, alkaline gritty loam, ideally in spring or summer. Let it sit in dry soil and do not water for about a week afterwards so any nicked roots can callus. Over-potting and watering straight away is what rots succulents.

What size pot does afghan iris need?

When is the best time of year to repot afghan iris?

Should you water afghan iris after repotting?

No — not straight away. Repot afghan iris into dry mix and wait about a week before the first watering so any damaged roots callus over. Watering a freshly repotted succulent is the single most common way to rot one.

Should you fertilise afghan iris after repotting?

Not immediately. Wait about 3 weeks after repotting afghan iris. Fresh mix already contains nutrients, and feeding freshly cut or disturbed roots burns them. Resume your normal feeding routine once you see new growth.