Repotting guide

When & how to repot Glandular Heron's Bill (Erodium glandulosum)

Also called Glandular Heron's Bill, Black-Eyed Heron's Bill, Glandular Stork's Bill.

More about glandular heron's bill

About Glandular Heron's Bill

Erodium glandulosum · also called Glandular Heron's Bill, Black-Eyed Heron's Bill · flowering

Erodium glandulosum is a compact herbaceous perennial native to the mountains of Spain and Portugal (Pyrenees and Iberian highlands), where it grows in rocky, well-drained limestone soils. It forms low, mound-like rosettes of glandular, silver-green, pinnately divided leaves and bears clusters of lilac-pink flowers with darker blotched upper petals throughout summer. The single most important care fact is that it demands sharp drainage and protection from prolonged winter wet, which will rot the crown far more readily than cold alone. Not documented as toxic to cats or dogs; classified as mildly-toxic due to limited species-specific ASPCA data.

Mature size: 15–20 cm tall, 20–30 cm wide after 2–3 years.

Watch for — Vine weevil larvae: Grubs feed on roots, causing sudden wilt; inspect roots when repotting and treat with nematodes (Steinernema kraussei) in early autumn.

How to tell glandular heron's bill needs repotting

Repotting on a calendar is less reliable than reading the plant. For glandular heron's bill, 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 glandular heron's bill

Every 2–3 years, into bone-dry mix. Glandular Heron's Bill's growth habit — low, cushion-forming herbaceous perennial, spreading slowly by basal rosettes. — sets the pace. Erodium glandulosum is a compact herbaceous perennial native to the mountains of Spain and Portugal (Pyrenees and Iberian highlands), where it grows in rocky, well-drained limestone soils. It forms low, mound-like rosettes of glandular, silver-green, pinnately divided leaves and bears clusters of lilac-pink flowers with darker blotched upper petals throughout summer. The single most important care fact is that it demands sharp drainage and protection from prolonged winter wet, which will rot the crown far more readily than cold alone. Not documented as toxic to cats or dogs; classified as mildly-toxic due to limited species-specific ASPCA data.

What size pot to step glandular heron's bill up to

Use a pot only one size up — or even the same pot with fresh gritty mix if the roots have room. Glandular Heron's Bill 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 glandular heron's bill

Spring or summer, while glandular heron's bill 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 glandular heron's bill

Repot dry. Do not water glandular heron's bill 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 gritty, sharply-drained, neutral to alkaline 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 glandular heron's bill 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 glandular heron's bill 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 glandular heron's bill

Glandular Heron's Bill wants gritty, sharply-drained, neutral to alkaline. Use a lean alpine mix — roughly equal parts loam, coarse grit, and pea gravel; avoid any moisture-retentive compost-rich blend. Always use fresh mix when you repot — reusing old, broken-down soil reintroduces the compaction and poor drainage you are repotting to fix.

Repotting glandular heron's bill — frequently asked questions

How often should you repot glandular heron's bill?

Every 2–3 years, into bone-dry mix for glandular heron's bill. Repot glandular heron's bill every 2–3 years into a snug pot of gritty, sharply-drained, neutral to alkaline, 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 glandular heron's bill need?

When is the best time of year to repot glandular heron's bill?

Should you water glandular heron's bill after repotting?

No — not straight away. Repot glandular heron's bill 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 glandular heron's bill after repotting?

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