1 named cultivar

‘Ogon’Mellow Yellow Spirea

shrub

Mellow Yellow Spirea

Spiraea thunbergii

The Story

Plant Bio

Spiraea thunbergii, Thunberg spirea, is a fine-textured arching deciduous shrub from Japan and China, three to five feet in both directions. Very slender zig-zag twigs carry narrow willow-like leaves, and in early spring the bare stems are lined with small white flowers before the foliage appears, giving a haze of white along every branch.

It is the earliest of the spireas by some weeks, flowering on bare wood before most shrubs have broken bud. The foliage is much finer than other spireas and colours orange in autumn. Prune within a few weeks of flowering: it blooms on the previous year's wood, so a late-winter tidy removes the whole display.

Uses & Benefits:

A haze of white along bare arching stems in very early spring, then fine foliage and orange autumn colour.

Hardy, undemanding and small enough for most gardens, with three seasons of interest.

Butterflies work the early flowers when little else is open.

Essentials

At a Glance

Plant Type

Shrub

Height

48 inches

Width

48 inches

Light

Full Sun, Partial Sun

Zones

4, 5, 6, 7, 8

Water

Moderate

Humidity

Moderate

Lifespan

Perennial

Native To

Japan and China

Toxicity

Non-toxic

Planting

How to Grow

Plant in full sun or partial shade in drained soil.
Allow four to five feet of width to arch naturally.
Water while establishing, then only in drought.
Prune within weeks of flowering, never later.
Thin the oldest stems at the base each year.
Avoid shearing, which destroys the arching form.

Pro Tip

Thin whole old stems at the base rather than shearing the outside — the arching fine-twigged habit is the reason to grow it.

Keep It Thriving

Care Guide

Do

Prune straight after flowering ✂️
Thin the oldest stems at the base 🪵
Give it room to arch 📏
Enjoy the orange autumn colour 🍂

Don't

Prune it in late winter ❌
Shear it into a ball ❌
Crowd it against other shrubs ❌

Seasonal Care Calendar

Task	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Enjoy
Prune

Watch Out For

Pests & Diseases

Common Pests

Common Diseases

In the Garden

Landscape Uses & Companions

Landscape Uses

Early spring flowering shrub borderInformal low hedge or bank plantingFine-textured contrast among coarser shrubs

Companion Plants

ForsythiaDaffodil Hellebore WeigelaCatmint

Multiply

Propagation Methods

Good to Know

Common Questions

Mellow Yellow Spirea questions

What zones can Mellow Yellow Spirea grow in?

Mellow Yellow Spirea is hardy in USDA Zones 4–8. Inside that range it survives winter in the ground; outside it, grow it as an annual or a container plant you protect.

Is Mellow Yellow Spirea deer resistant?

Yes — Mellow Yellow Spirea is rated deer-resistant. Deer typically pass it over, though extreme hunger can override any plant's defenses.

When does Mellow Yellow Spirea bloom?

Mellow Yellow Spirea typically blooms in early spring through mid-spring. Exact timing shifts a week or two with your zone — Sow's bloom calendar maps it to your garden.

Does Mellow Yellow Spirea need full sun?

Mellow Yellow Spirea does best in full sun to part shade. In hot climates, afternoon shade keeps blooms fresher longer.

Is Mellow Yellow Spirea drought tolerant?

Yes — once established (usually after the first full season), Mellow Yellow Spirea handles dry spells with minimal watering. Water deeply its first year to build the root system that makes that possible.