Type

Flower · Perennial

Botanical family

Mixed / other

Foliage color

Green

Flower color

Pink

Sunlight

Full sun

Watering

Low to moderate

Soil

Any open, drained soil; famously first onto burned and broken ground

Feeding

Gentle all-organic

USDA zones

2a–7a

Frost tolerant

Yes

Sow direct

21 days before the last spring frost

Plant out

at the last spring frost

Plant spacing

17.7 in

In-row spacing

15.7 in

Between rows

23.6 in

Square-foot density

Not suited to SFG

Sow depth

0 in

Root system

Running rhizomes

Working depth

4–12 in

Can reach

18 in down where the soil allows

Spread

4–8 ft across, about 2–4× the width of the plant

Shallowest pot

12 in of soil

It travels underground, and it does not stop where you would like it to. Taking the tops off does nothing at all to the run, and every fragment left behind is a new plant. In open ground the only boundary that holds is a barrier sunk two spits deep, or a container with its rim standing clear of the soil.

It runs hard at the root and seeds itself by the thousand besides, which is how it colonises burnt ground in a season. In a border it is a decision rather than a plant.

The habit is Fireweed’s own; the figures are what that habit usually comes to at this size, not a measurement of this species. Roots follow the soil either way: a compacted pan, a high water table or heavy clay stops them well short of any of it, and deep open ground lets them go further.

We say a plant is safe only where a named poison-control reference names that exact species and records it as non-toxic to both cats and dogs. Most plants are on nobody’s list, and their absence here is not a judgement about them. This is a record of what those references say, not veterinary advice, and it cannot account for your own animal, the quantity eaten, or a plant treated with anything.

The ASPCA still files this species under the older name Epilobium angustifolium; we file it as Chamerion angustifolium. Its Great Willow Herb, Willow Herb and Blooming Sally rows are the same species. Its Rosebay row is Rhododendron spp., a different plant.

More about plants and pets

When

Young shoots in spring for the adventurous; flowers and leaves for tea in summer; and the crucial cut before the silk flies.

What to look for

For containment, pods forming up the lower stem while the top still blooms: cut now or gather ten thousand seedlings later.

How to harvest

Cut the wands down as the last flowers fade at the tip, before pods split. Young spring shoots steam like asparagus; fermented leaves are the Russian ivan chai.

How often

One decisive cut a year, plus edge patrol on the running roots.

Storing the crop

Dried leaves and flowers keep a year for tea. The plant needs no storing; it needs supervising.

• Rust Rust on the leaves some years
• Runs at the root in soft garden soil: give it a mowed edge or a buried barrier and it is no trouble