Repotting guide

When & how to repot Soft Draba (Draba mollissima)

Also called Soft Draba, Caucasus Cushion Draba.

More about soft draba

About Soft Draba

Draba mollissima · also called Soft Draba, Caucasus Cushion Draba · flowering

Draba mollissima is a specialist cushion alpine endemic to the North Caucasus, where it forms flat to hemispherical pads of minute, densely white-hairy rosettes in dry rocky crevices and scree at 2,500–3,500 m elevation. In cultivation it produces fragrant yellow flowers in spring on short scapes above a perfectly symmetrical cushion just 3–10 cm across. It is considered a challenging plant requiring an alpine house or extremely well-drained trough with complete protection from winter wet; experienced alpine growers describe it as one of the most exacting Drabas. Toxicity data are absent from the ASPCA database; classified as mildly-toxic as a precautionary measure.

Mature size: 3–8 cm tall and 5–10 cm across.

How to tell soft draba needs repotting

Repotting on a calendar is less reliable than reading the plant. For soft draba, 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 soft draba

Every 2–3 years, into bone-dry mix. Soft Draba's growth habit — tightly compressed cushion perennial composed of minute, densely white-hairy evergreen rosettes; extremely slow-growing. — sets the pace. Draba mollissima is a specialist cushion alpine endemic to the North Caucasus, where it forms flat to hemispherical pads of minute, densely white-hairy rosettes in dry rocky crevices and scree at 2,500–3,500 m elevation. In cultivation it produces fragrant yellow flowers in spring on short scapes above a perfectly symmetrical cushion just 3–10 cm across. It is considered a challenging plant requiring an alpine house or extremely well-drained trough with complete protection from winter wet; experienced alpine growers describe it as one of the most exacting Drabas. Toxicity data are absent from the ASPCA database; classified as mildly-toxic as a precautionary measure.

What size pot to step soft draba up to

Use a pot only one size up — or even the same pot with fresh gritty mix if the roots have room. Soft Draba 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 soft draba

Spring or summer, while soft draba 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 soft draba

Repot dry. Do not water soft draba 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 gritty, mineral, sharply drained mix 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 soft draba 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 soft draba 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 soft draba

Soft Draba wants extremely gritty, mineral, sharply drained mix. Use a lean alpine mix of 1 part loam-based compost to 3 parts coarse grit or crushed granite chips; avoid any organic-rich compost that retains 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 soft draba — frequently asked questions

How often should you repot soft draba?

Every 2–3 years, into bone-dry mix for soft draba. Repot soft draba every 2–3 years into a snug pot of extremely gritty, mineral, sharply drained mix, 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 soft draba need?

When is the best time of year to repot soft draba?

Should you water soft draba after repotting?

No — not straight away. Repot soft draba 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 soft draba after repotting?

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