Repotting guide

When & how to repot Silver Thyme (Thymus vulgaris 'Silver Posie')

Also called silver thyme, variegated thyme.

More about silver thyme

About Silver Thyme

Thymus vulgaris 'Silver Posie' · also called silver thyme, variegated thyme · herb

Silver thyme is an ornamental, cream-and-grey variegated form of common thyme with the same warm, savoury flavour and pink-tinged new growth. A hardy, low, woody Mediterranean sub-shrub, it thrives in poor, sharply drained soil and full sun, shrugs off drought, and makes an evergreen edging or container herb that resents wet feet above all.

Mature size: 15-25 cm tall and 30-40 cm wide (6-10 in tall, 12-16 in wide)

Watch for — Root rot from overwatering: The number-one killer. Soggy soil rots the crown and roots; plant in gritty, free-draining soil and water sparingly, letting it dry between drinks.

How to tell silver thyme needs repotting

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

Every 2–3 years, into bone-dry mix. Silver Thyme's growth habit — a low, spreading, evergreen woody sub-shrub forming a dense mound of tiny silver-edged grey-green leaves with pink-flushed tips; bears small pale lilac flowers in early summer that bees love. woodiness at the base increases with age. — sets the pace. Silver thyme is an ornamental, cream-and-grey variegated form of common thyme with the same warm, savoury flavour and pink-tinged new growth. A hardy, low, woody Mediterranean sub-shrub, it thrives in poor, sharply drained soil and full sun, shrugs off drought, and makes an evergreen edging or container herb that resents wet feet above all.

What size pot to step silver thyme up to

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

Spring or summer, while silver 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 silver thyme

Repot dry. Do not water silver 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 poor, gritty, sharply drained 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 silver 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 silver 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 silver thyme

Silver Thyme wants poor, gritty, sharply drained alkaline to neutral soil. A Mediterranean plant that wants lean, free-draining soil, ideally with added grit or sand; pH 6.0-8.0. Rich or heavy clay soil makes it soft and short-lived. In pots use a free-draining mix with extra perlite or grit. Always use fresh mix when you repot — reusing old, broken-down soil reintroduces the compaction and poor drainage you are repotting to fix.

Repotting silver thyme — frequently asked questions

How often should you repot silver thyme?

Every 2–3 years, into bone-dry mix for silver thyme. Repot silver thyme every 2–3 years into a snug pot of poor, gritty, sharply drained 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 silver thyme need?

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

Should you water silver thyme after repotting?

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

Not immediately. Wait about 3 weeks after repotting silver 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.