Light
Medium, indirect
Ideal spot
Adiantum raddianum 'Fritz Luthii' · Fern · pet-safe
Medium, indirect
Ideal spot
2–3 times a week
In the growing season
Demanding
Moderate grower
Safe
Cats & dogs
Fritz Luthii Maidenhair Fern (Adiantum raddianum 'Fritz Luthii') belongs to the Polypodiaceae family and is a demanding houseplant to look after. This moderate grower plant is happiest in medium, indirect and reaches 20–40 cm indoors.
For watering, the rule is simple: keep evenly moist. In the growing season it needs water roughly every 3 days, dropping to every 6 days in winter. Use the watering calculator below to tune that rhythm to your pot size, light and household humidity.
Good news for pet owners: Fritz Luthii Maidenhair Fern is listed as non-toxic to cats and dogs by the ASPCA.
Set your pot size, light and humidity — the calculator tunes the watering rhythm to your home.
Light at the spot
Humidity
Season
Water Fritz Luthii Maidenhair Fern
every 3 days
≈ 2–3 times a week · 10× per month
Let the top 2–3 cm dry and finger-check before watering again.
Fritz Luthii Maidenhair Fern prefers medium, indirect but will cope with low to medium. Harsh midday sun can scorch sensitive leaves, while too little light leads to leggy, sparse growth.
Keep Fritz Luthii Maidenhair Fern between 16–24 °C and aim for around 75% humidity (60% minimum). Below 10 °C it risks cold damage — keep it away from draughty windows and radiators.
16–24 °C
Not below 10 °C
75%
60% minimum
Keep evenly moist
Soil between waterings
Pot Fritz Luthii Maidenhair Fern in moisture-retentive, peat-free mix with leaf mould. A drainage hole is essential — soggy, airless soil is the single most common way houseplants die.
Listed as non-toxic to cats and dogs by the ASPCA — a genuinely pet-safe choice.
The best ways to propagate Fritz Luthii Maidenhair Fern are division and spores. Late spring and summer are ideal, when the plant is growing most actively.
Maidenhair fern's wiry black stems shed water like wax — the name means 'unwetted', and it demands constant moisture and high humidity to keep its lacy fronds.
In the growing season Fritz Luthii Maidenhair Fern needs watering 2–3 times a week (about every 3 days in a 16 cm pot at medium light), and much less in winter — roughly every 6 days. Use the watering calculator above to get the exact interval for your conditions.
Fritz Luthii Maidenhair Fern thrives in medium, indirect. A spot near a bright window out of harsh midday sun is ideal; give it a little more light in winter.
Fritz Luthii Maidenhair Fern is non-toxic to pets. Listed as non-toxic to cats and dogs by the ASPCA — a genuinely pet-safe choice.
The most common problem with Fritz Luthii Maidenhair Fern is crispy fronds. Check your watering and drainage first — most issues trace back to too much or too little water.
The best ways to propagate Fritz Luthii Maidenhair Fern are division and spores. Late spring and summer are ideal, when the plant is growing most actively.
Indoors Fritz Luthii Maidenhair Fern typically reaches 20–40 cm. With the right light and occasional repotting it stays compact and bushy.
Care data last verified on 15 June 2026.
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