Repotting guide

When & how to repot Woolly Thyme (Thymus pseudolanuginosus)

More about woolly thyme

About Woolly Thyme

Thymus pseudolanuginosus · herb

Woolly thyme is a flat, mat-forming groundcover thyme grown for its dense, silvery, fuzzy grey-green foliage rather than for cooking. It thrives in full sun and sharp drainage, tolerates foot traffic, and spreads to fill gaps between paving and rockery stones. It rarely flowers and dislikes wet, heavy soil.

Mature size: 2-5 cm tall, spreading 30-45 cm or more per plant

How to tell woolly thyme needs repotting

Repotting on a calendar is less reliable than reading the plant. For woolly thyme, 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 woolly thyme

Every 2–3 years, into bone-dry mix. Woolly Thyme's growth habit — prostrate, ground-hugging evergreen mat. stems creep horizontally and root where they touch soil, forming a tight 2-3 cm tall carpet that spills over edges and between stones. — sets the pace. Woolly thyme is a flat, mat-forming groundcover thyme grown for its dense, silvery, fuzzy grey-green foliage rather than for cooking. It thrives in full sun and sharp drainage, tolerates foot traffic, and spreads to fill gaps between paving and rockery stones. It rarely flowers and dislikes wet, heavy soil.

What size pot to step woolly thyme up to

Use a pot only one size up — or even the same pot with fresh gritty mix if the roots have room. Woolly Thyme 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 woolly thyme

Spring or summer, while woolly thyme 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 woolly thyme

Repot dry. Do not water woolly thyme 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 lean, gritty, free-draining alkaline to neutral soil 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 woolly thyme 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 woolly thyme 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 woolly thyme

Woolly Thyme wants lean, gritty, free-draining alkaline to neutral soil. Use a sandy or gravelly mix with low fertility; add horticultural grit to heavy ground. Soggy or rich soil triggers crown rot and dieback in the centre of the mat. Always use fresh mix when you repot — reusing old, broken-down soil reintroduces the compaction and poor drainage you are repotting to fix.

Repotting woolly thyme — frequently asked questions

How often should you repot woolly thyme?

Every 2–3 years, into bone-dry mix for woolly thyme. Repot woolly thyme every 2–3 years into a snug pot of lean, gritty, free-draining alkaline to neutral soil, 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 woolly thyme need?

When is the best time of year to repot woolly thyme?

Should you water woolly thyme after repotting?

No — not straight away. Repot woolly thyme 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 woolly thyme after repotting?

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