Grow and Care for Fireweed

Grow fireweed in full sun, in moist soil that still drains. Fireweed is Chamaenerion, a tall meadow perennial that runs by rhizomes.

Give it full sun and moist soil that drains

fireweed wants an open, sunny meadow and ground that stays moist without turning into a bog. Catalog plants stand about 2 to 5 feet tall. Light afternoon shade is useful in a hot summer, but deep shade makes weak stems and the patch fades. [1] Water enough the first season so the rhizomes take. Once it is established, a short dry spell is safer than soggy clay. Neighbours that close over the top will crowd it out.

1. Set it in full sun. Afternoon shade is tolerable in heat, but the racemes stay fuller in open light.
2. Keep the soil moist until the plant is established. After that, a short dry spell is safer than standing water.
3. Skip heavy feeding. Extra fertilizer pushes leaves and makes the colony harder to hold.

Sow seed on the surface

The seed is tiny and needs light, so press it onto bare soil. Do not bury it. A fall sowing on a weed-free patch lets winter weather do the work, or you can sow onto warm, moist mix and expect sprouts in about 10 days. [2] Native-seed packets often add a 30 to 60 day moist chill before a spring sowing. Scrape away leaf litter so the seed sits on mineral soil, then keep that surface evenly moist until seedlings show.

1. Press the seed onto the surface. Do not cover it with more than a dusting of mix.
2. Sow in fall on bare ground, or keep a spring tray warm and moist until sprouts show, usually in about 10 days.
3. If you sow in spring from a stored packet, a 30 to 60 day moist chill in the refrigerator can improve the stand.
4. Keep the surface moist until the seedlings have true leaves, then thin in place.

Divide rhizomes in spring or fall

An established clump is easier to start from a rhizome than from seed. Lift a piece of the runner in spring or fall, keep a bud and some root on each section, and replant it at once at the same depth it grew. Root pieces about 2 inches deep will send up new shoots. Fragmented rhizomes sprout freely, so do not leave scraps in a bed you meant to clear.

1. Lift a rhizome in spring or fall, when the soil is workable.
2. Cut sections that each have a bud and some root, then replant at the same depth.
3. Water in once, and keep the soil moist until new shoots show.

Set plants 1 to 2 feet apart, with a rhizome barrier

Set a nursery plant or a divided piece at the same depth it grew, 1 to 2 feet from its neighbour. The colony will still run, so if you are planting in a mixed border, sink a rhizome barrier at least 6 inches deep around the patch, or give it a meadow of its own. [3] Water in once, then keep the soil moist until new growth shows. A few plants are enough; the runners will fill the gap.

1. Plant at the same depth the nursery pot or rhizome grew, 1 to 2 feet apart.
2. Sink a rhizome barrier at least 6 inches deep if the bed has to stay mixed, or site the patch where a colony is welcome.
3. Water in, then keep the soil moist until new shoots take.
4. Pull stray runners that appear outside the barrier the same season they show.

Grow it in a pot if you need to contain it

A large pot with a drainage hole is the clean way to grow fireweed on a patio or in a small yard. Use a potting mix that stays moist but still drains, and empty the saucer after you water. The runners fill a pot fast, so many gardeners start a fresh plant each spring rather than wrestling a crowded root mass through winter.

1. Choose a pot with a drainage hole. Empty the saucer after you water.
2. Use a potting mix that stays moist but still drains. Do not pack garden clay into the pot.
3. Water when the top of the mix begins to dry. Skip heavy feed, which only speeds the spread.

Not purple loosestrife or California fuchsia

Fireweed has four egg-shaped petals, a round reddish stem, and alternate willow-like leaves. Purple loosestrife has five to seven narrow petals, a square stem, and opposite leaves — do not plant it. [4] California fuchsia is a different plant, Epilobium canum, with scarlet tubes on dry sun — see How to Grow California Fuchsia. Woody willow is Salix — see How to Grow Willow. Hanging-basket fuchsia is a tender shrub — see How to Grow Fuchsias. An old tag that says Epilobium angustifolium is still fireweed, not California fuchsia. Confirm the Latin before you count on dry-bank care.

Cut spent stems before the seed plumes fly

Cut the raceme when the last flowers fade if you do not want silky seed on the wind. Leave the stems standing into fall if you want the plumes, then cut the tops to the ground after frost, or in late winter before new shoots rise. Regular cutting also keeps the plant from looking ragged after bloom.

1. Cut spent flower stems before the capsules split if you need to limit seedlings.
2. Cut the remaining tops to the ground after frost, or in late winter.
3. Do not leave chopped rhizomes in a bed you meant to clear. Each piece can send a new shoot.

If you want more fireweed, divide a rhizome in spring, or collect the silky seed before the wind takes it. If you want less, cut the spikes before they fluff.