Repotting guide

When & how to repot Cosson's Germander (Teucrium cossonii)

Also called Cosson's germander, Balearic germander.

More about cosson's germander

About Cosson's Germander

Teucrium cossonii · also called Cosson's germander, Balearic germander · flowering

Teucrium cossonii is a low-growing, prostrate sub-shrub endemic to the Balearic Islands (Majorca and Ibiza), where it scrambles over sun-baked limestone rocks and coastal scrub. It is grown for its dense silver-grey felted foliage and bright cerise to pink-purple flowers produced over a long summer season. The most important care consideration is outstanding drainage and full sun — waterlogged roots in winter cause rapid death, making it best suited to a dry wall top, raised scree bed, or alpine house in wetter climates. Treat as mildly toxic to pets, consistent with the Teucrium genus.

Mature size: 5–15 cm tall and 30–60 cm wide.

Watch for — Root rot in winter wet: The primary cause of losses in UK and PNW gardens; even short periods of waterlogging during cold weather rot the fine roots and crown. Grow in raised scree beds or against a dry, south-facing wall.

How to tell cosson's germander needs repotting

Repotting on a calendar is less reliable than reading the plant. For cosson's germander, 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 cosson's germander

Every 2–3 years, into bone-dry mix. Cosson's Germander's growth habit — prostrate to low-spreading, mat-forming evergreen sub-shrub with dense silver felted stems. — sets the pace. Teucrium cossonii is a low-growing, prostrate sub-shrub endemic to the Balearic Islands (Majorca and Ibiza), where it scrambles over sun-baked limestone rocks and coastal scrub. It is grown for its dense silver-grey felted foliage and bright cerise to pink-purple flowers produced over a long summer season. The most important care consideration is outstanding drainage and full sun — waterlogged roots in winter cause rapid death, making it best suited to a dry wall top, raised scree bed, or alpine house in wetter climates. Treat as mildly toxic to pets, consistent with the Teucrium genus.

What size pot to step cosson's germander up to

Use a pot only one size up — or even the same pot with fresh gritty mix if the roots have room. Cosson's Germander 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 cosson's germander

Spring or summer, while cosson's germander 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 cosson's germander

Repot dry. Do not water cosson's germander 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 extremely free-draining, poor, calcareous or neutral 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 cosson's germander 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 cosson's germander 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 cosson's germander

Cosson's Germander wants extremely free-draining, poor, calcareous or neutral. Best in a gritty scree mix (2 parts coarse grit : 1 part loam : 1 part peat substitute) or wedged into the crevices of a dry stone wall; never plant in clay or moisture-retentive soil. Always use fresh mix when you repot — reusing old, broken-down soil reintroduces the compaction and poor drainage you are repotting to fix.

Repotting cosson's germander — frequently asked questions

How often should you repot cosson's germander?

Every 2–3 years, into bone-dry mix for cosson's germander. Repot cosson's germander every 2–3 years into a snug pot of extremely free-draining, poor, calcareous or neutral, 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 cosson's germander need?

When is the best time of year to repot cosson's germander?

Should you water cosson's germander after repotting?

No — not straight away. Repot cosson's germander 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 cosson's germander after repotting?

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