Species Swamp Moonwort
red sporangia with lime foliage and stems

Swamp Moonwort

Botrychium tenebrosum

Swamp Moonwort (Botrychium tenebrosum) is an easily overlooked fern-like plant found in wooded wetlands. Its attractive, fine-textured fronds are delicate and fern-like but coarser with persistent, plate-like pinnae. Immediately recognizable by its crescent moon shape, Swamp Moonwort grows in wet meadows, shallow standing water, swamps, wet sloughs, and even ditches and roadside as long as it is not subjected to long-term drying. Its flowers are greener than its fronds and hang in clusters on the underside of the stem. It is a perennial herb with a slow growth rate and its maximum height rarely exceeds 18 inches.

Watering:

Minimum

Hardiness Zone:

Sun:

part shade,full shade

Leaf:

Yes

Leaf Color:

green,yellow

Growth Rate:

Low

watering

Least Moonwort (Botrychium simplex var. simplex) should be watered in moderation. Water the plant lightly 1 or 2 times per month in the spring and summer months, but reduce watering in the winter months as the plant enters its dormant phase. A general rule of thumb is to water when the top 2 inches of soil feel dry. Be sure to remove any excess water and do not allow the plant to sit in soggy soil for an extended period of time.

sunlight

Least Moonwort prefers partial shade to full sun and, as such, should receive a minimum of 3-4 hours of direct sunlight each day. It should never be exposed to more than 8 hours of direct sunlight in a single day as this can cause the plant stress. For best results, a mid-morning to mid-afternoon sun is best for this particular species. It should be noted that this species is most tolerant of deep shade and may suffer in full sun; err on the side of caution and provide a light shade if conditions allow.

pruning

Least Moonwort (Botrychium simplex var. simplex) should be lightly pruned in late summer or early fall, right after the plants finish flowering and the foliage begins to fade. Overly aggressive pruning should be avoided, as this plant species tends to form a tight clump, so it is better to merely snip off the faded flower heads and yellowing leaves along with pruning any dead stems. When cutting back, it is best to stop just above a leaf or healthy bud, so as not to leave an open wound on the stems. Pruning should be done cautiously, as this plant species is a very fragile fern and is quick to go dormant.

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