Manton's Polypody Polypodium × mantoniae 'Cornubiense'

Water

The Cornish fern, or Polypodium × mantoniae 'Cornubiense', should be watered thoroughly but infrequently, allowing the soil to dry out slightly between waterings. This plant prefers to stay moist but not waterlogged; overwatering can lead to root rot. Generally, watering once every week or two with about 16 to 32 ounces of water, depending on the pot size and environmental conditions, should suffice. During the active growing season in spring and summer, you might need to water more frequently, while in the cooler dormant months, watering should be reduced. Always check the top inch of the soil for dryness before watering to ensure the plant actually needs additional moisture.

Light

The Cornish fern thrives best under partial to full shade conditions, avoiding direct sunlight that can scorch its leaves. This fern is well-suited to indoor environments where bright, indirect light is present. A spot near a north or east-facing window where the rays of the sun are most gentle, or a location with dappled sunlight, is ideal for the Cornish fern to maintain its vibrant green foliage.

Temperature

The Cornish fern prefers a moderate temperature range, doing well in environments between 60 and 75 degrees Fahrenheit. It should not be exposed to temperatures below 50 degrees Fahrenheit, as it might not withstand the cold and could suffer damage. The ideal temperature conditions come close to the cool to moderate climates often found in its native habitat, allowing this fern to thrive without the stress of extreme temperature fluctuations.

Pruning

Pruning the Cornish fern is mostly for aesthetic reasons, to remove any yellowing or dead fronds and to maintain a tidy appearance. Pruning can be done at any time of the year as needed, but it's best done in the spring to make way for new growth. Simply use clean, sharp scissors or pruning shears to cut back the undesired fronds to the base. Avoid excessive pruning to ensure the fern maintains its natural shape and appeal.

Cleaning

As needed

Soil

For Polypodium x mantoniae 'Cornubiense', commonly known as Manton's Polypody, the best soil mix is one part peat, one part pine bark, and one part perlite. This combination provides excellent drainage and aeration, key for fern health. The ideal soil pH for Manton's Polypody ranges from slightly acidic to neutral, approximately pH 5.5 to 7.

Repotting

Manton's Polypody should be repotted approximately every two to three years or when the plant has outgrown its current container. Repotting is best done in the spring before the start of the active growing season, giving the plant time to establish in its new pot.

Humidity & Misting

Manton's Polypody thrives in a high humidity environment, ideally between 60% and 80%. It is essential to maintain consistent humidity levels, especially if the plant is grown indoors where the air can be drier.

Suitable locations

• Indoor

  Place in bright, indirect light with high humidity.

• Outdoor

  Keep in shade, shelter from winter, and ensure moist.

• Hardiness zone

  8-10 USDA

Life cycle

Polypodium × mantoniae 'Cornubiense', commonly known as the hybrid fern 'Cornubiense', begins its life cycle with spore germination, leading to a tiny prothallus—a small, gametophyte phase. On the prothallus, sperm is produced in antheridia and eggs in archegonia; fertilization occurs when water allows sperm to swim to the eggs, forming a new sporophyte plant. This young plant gradually develops roots, fronds, and rhizomes, with the fronds unfurling through a process called circinate vernation. Over time, the fern matures, producing differentiated fronds that perform photosynthesis and contribute to the growth of the plant. Once mature, the fronds develop sporangia, typically on the undersides, where spores are produced through meiosis. These spores are then released to the environment to start a new cycle when conditions are favorable.

Propogation

• Propogation time

  Spring to Summer

• Propogation: The most popular method for propagating Polypodium × mantoniae 'Cornubiense', commonly known as the Manton's Polypody, is through division, which is best done in spring or early autumn. To propagate via division, carefully lift the parent plant and use a sharp knife or spade to divide the root system into smaller sections, ensuring each new section has a portion of the roots and fronds. These divisions can then be replanted into pots with well-draining potting mix or directly into the garden, maintaining consistent moisture until the new plants are established. The divisions should be spaced adequately to allow for growth, and they should be kept in a shaded or semi-shaded location as they acclimate to their new environment. After planting, water the divisions well and keep them well-hydrated, without waterlogging the soil, to encourage root development and growth.