Repotting guide

When & how to repot Hummingbird Mint (Agastache rupestris)

Also called sunset hyssop, hummingbird mint, rock anise hyssop.

More about hummingbird mint

About Hummingbird Mint

Agastache rupestris · also called sunset hyssop, hummingbird mint · herb

Agastache rupestris, sunset hyssop, is an aromatic Southwest US native with fine, threadlike grey-green leaves and slender spikes of smoky-orange flowers with lavender calyces from summer into autumn. Smelling of root beer and mint, it thrives in full sun and sharp drainage, tolerates heat and drought, and draws hummingbirds and bees.

Mature size: About 60-90 cm tall and 30-45 cm wide (2-3 ft by 1-1.5 ft).

Watch for — Flopping / legginess: Results from shade or rich soil. Grow in full sun and lean ground for self-supporting, compact stems.

How to tell hummingbird mint needs repotting

Repotting on a calendar is less reliable than reading the plant. For hummingbird mint, 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 hummingbird mint

Every 2–3 years, into bone-dry mix. Hummingbird Mint's growth habit — upright, airy, clump-forming aromatic perennial with fine, needle-like foliage and slender, many-branched flower spikes; mint-family relative with a long bloom season. — sets the pace. Agastache rupestris, sunset hyssop, is an aromatic Southwest US native with fine, threadlike grey-green leaves and slender spikes of smoky-orange flowers with lavender calyces from summer into autumn. Smelling of root beer and mint, it thrives in full sun and sharp drainage, tolerates heat and drought, and draws hummingbirds and bees.

What size pot to step hummingbird mint up to

Use a pot only one size up — or even the same pot with fresh gritty mix if the roots have room. Hummingbird Mint 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 hummingbird mint

Spring or summer, while hummingbird mint 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 hummingbird mint

Repot dry. Do not water hummingbird mint 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, sharply drained 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 hummingbird mint 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 hummingbird mint 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 hummingbird mint

Hummingbird Mint wants lean, gritty, sharply drained soil. Sandy, gravelly or rocky soil with excellent drainage is essential. It hates heavy, fertile or wet ground. Neutral to slightly alkaline pH around 6.5-7.5 suits this xeric native. Always use fresh mix when you repot — reusing old, broken-down soil reintroduces the compaction and poor drainage you are repotting to fix.

Repotting hummingbird mint — frequently asked questions

How often should you repot hummingbird mint?

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

When is the best time of year to repot hummingbird mint?

Should you water hummingbird mint after repotting?

No — not straight away. Repot hummingbird mint 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 hummingbird mint after repotting?

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