Grow and Care for Rattlesnake Fern

Grow rattlesnake fern in woodland shade, in moist humus. Rattlesnake fern here is Botrychium virginianum, also called common grape fern — not the houseplant rattlesnake plant, and not rattlesnake master.

Give it woodland shade and moist, humus-rich soil

rattlesnake fern is a deciduous woodland fern with one annual stalk. That stalk splits well above the ground into a lacy sterile blade and a fertile spike of bead-like spore cases. [1] Site it in part shade or deep shade, in moist acidic humus. The roots depend on fungi in that soil, so a dry, disturbed bed is the wrong start. [2]

1. Choose a shady woodland strip, a north slope, or the north side of deciduous trees.
2. Keep the soil evenly moist through spring and summer. Water again before the leaf litter dries, and do not leave the crown sitting in a puddle.
3. Work in leaf mold or decaying woodland debris so the mix stays humus-rich without turning to mud.
4. Skip lime, wood ash, and a strong fertilizer around the roots — those change the fungi the plant needs.

Plant a nursery plant — do not dig a wild clump

This fern is hard to move. Digging a wild plant usually kills it because the fleshy roots need the fungi in that soil. If you can find a nursery plant, set it in already moist woodland shade and keep the nursery soil on the roots. [3]

1. Leave wild plants in the woods. Do not cut a sod out of a trail edge or a neighbor's lot.
2. Buy a nursery plant when one is offered. This fern is not a common garden-center fern, so a woodland specialty nursery is the usual source.
3. Dig a hole as deep as the pot and a little wider, in already moist humus. Do not shake the soil off the roots.
4. Set the crown at the same depth it grew in the pot. Do not bury the growing point.
5. Water to settle, mulch with shredded leaves, and keep the mulch off the crown. Skip a starter fertilizer in the hole.

Do not split the clump

Division usually fails. The fleshy roots and the fungi around them need to stay together.

1. Leave an established plant in place.
2. Do not tease the roots apart or wash the soil off a nursery ball.
3. If you must move a potted plant, keep the whole root ball intact and replant at once in moist shade.

Leave the single frond until it withers

Each plant makes one frond a year. That blade feeds the roots through summer, then yellows and disappears by late summer or fall. Do not shear a green plant to the ground.

1. Leave the green sterile blade in place through the growing season. It is the only leaf.
2. After the fertile spike browns and drops spores, you may cut that spent spike at the base if it bothers you.
3. When the sterile blade yellows in late summer, let it wither. Do not pull a still-green stalk.
4. Wait for a new frond in spring. The plant is underground in winter; it is not dead.

Not a rattlesnake plant — and not rattlesnake master

A shop tag that says rattlesnake plant is usually a houseplant with long wavy leaves marked like a snake — that is Goeppertia, sold as Calathea. See How to Grow Peacock Plant for that indoor mix. Rattlesnake master is Eryngium, a prairie plant with yucca-like leaves and a thistle head — see How to Grow Sea Holly.

Rattlesnake plantain is a woodland orchid with a white-veined rosette, not a fern. Cutleaf grape fern is a relative with leathery evergreen blades; this plant is thin-textured and deciduous, and its sterile blade sits on a shared stalk well above the ground. [4] Christmas fern is Polystichum — see How to Grow Holly Fern if the fronds are leathery and stocking-shaped. A tag that says moonwort may be Lunaria, the silver-dollar plant — see How to Grow Lunaria.

Keep woodland shade and moist humus, plant a nursery plant instead of digging a wild clump, and leave the one frond until it withers so the roots can store what they need.