Royal Fern is a perennial grown for its blooms, which open in summer and return year after year. It's hardy across USDA zones 4 through 10 and shrugs off deer.
Royal Fern — the short answer
Royal Fern: grown in zones 4–10, part sun, pH 4–6.
- USDA zones
- 4–10
- Manual horticultural correction (source not retained); NC State Extension and Missouri Botanical Garden, with the remaining rows from other published sources or Growable Ground compilation
- Soil pH
- 4–6
- USDA PLANTS
- Sun
- Part Sun
- Growable Ground Plant Database
Plant data: Growable Ground Plant Database, compiled from FAO ECOCROP, USDA PLANTS and university Extension sources — each tile names its own row's source, because per-field provenance varies.
Score Royal Fern on your exact land.
Zone averages can't see the slope, soil, frost, and sun that decide whether royal fern actually takes — and those shift from one yard to the next. Enter your address and we'll score royal fern against your land's real conditions.
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What Royal Fern is
Royal Fern grows as a perennial and reaches around four feet at maturity. It blooms in summer. It's also deer-resistant.
How to grow Royal Fern
Royal Fern grows in USDA zones 4 through 10. Royal Fern does best in part sun — at least 4 hours of direct sun a day — and soil from pH 4 to 6, on consistently moist ground.
USDA Zones
4-10
USDA PHZM 2023
Soil pH
4 - 6
USDA PLANTS
Sun
Part Sun
Growable Ground plant catalog
Drainage
poorly (saturated >50% of year)
Growable Ground plant catalog
Cold Hardiness
-38°F
The coldest temperature this plant is documented to survive.
USDA PLANTS
Mature Height
4 ft
Growable Ground plant catalog
Frost-Free Days
0+
The frost-free stretch it needs start to finish — short-season areas may need an indoor head start.
Growable Ground plant catalog
Start the season right
Plant royal fern in part sun with at least 4 hours of direct sun.
Match the soil
Royal Fern prefers pH 4 to 6 (USDA PLANTS). A quick soil test from your local Extension lab tells you whether to add lime or sulfur to land in band.
Water steadily
Keep the root zone evenly moist through establishment. Match watering to the plant's drainage preference and your local rainfall.
Harvest at its peak
Cut royal fern blooms in the cool of the morning, just as they open, for the longest display.
Where Royal Fern thrives
Royal Fern is hardy across USDA zones 4 through 10. Zone is only the starting point, though: the soil pH, drainage, and frost dates on your specific land decide how well it actually does.
A USDA zone is a 10°F band of average annual extreme winter minimum, so zones 4–10 spans average winter lows from -30°F to 40°F (USDA PHZM 2023). Across the 50 states and DC, that band covers 38 outright and splits 13 more down the middle — and which side of that line your land sits on changes the answer.
Zones 4–10·Where Royal Fern growsOpen map →
Where Royal Fern stands, state by state
Royal Fern is rated for zones 4–10 — a cold floor USDA puts at -30 to -20°F. Across the 50 states and DC, 38 sit fully inside that band, the line runs through 13 more, and 0 sit outside it — and inside every split state, the same line runs on at county grain.
Fully inside zones 4–10
38 states
3 of 38 shown
State zone extents: USDA Plant Hardiness Zone Map (PHZM) 2023. A zone is a 10°F band of average annual extreme minimum temperature, so a state that splits the band contains the boundary — its own page draws the county line, and a parcel report resolves which side your land sits on.
What grows around Royal Fern
Growing guides for royal fern
In rotation planning, royal fern counts as a Other — beds recover best when other crops don’t follow each other in the same spot year over year. (Growable Ground derivation — crop-rotation group from botanical family)
Related plants in perennial flower
Good to know
Good news for pet owners — royal fern isn't known to be toxic to dogs or cats. (Source: ASPCA.)
Royal Fern isn't classified as a notable pollinator plant in our data — pair it with high-value bloomers nearby to feed bees.
Your land is one point inside Royal Fern's range
This page resolves to the species. Your state page draws the county line, and a report reads the parcel — the soil pH, drainage, sun, and frost dates on your exact ground, which no species average can see.
See if Royal Fern will thrive on your land
Zone averages are a start. Your exact soil pH, drainage, sun exposure, and frost dates shape whether royal fern actually takes — we score it against the real conditions at your address.
Three things about your exact spot that zone averages miss:
We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.
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How we know this about Royal Fern
The figures above are cited per row, not per site: the pH band names this plant’s own source column, the three temperature figures each carry their own, and days-to-maturity cites the publication that actually lists it. All of it comes from the Growable Ground Plant Database — a compilation over FAO ECOCROP, USDA PLANTS, and university Extension sources, published openly with per-field provenance.
Grounded inUSDA PLANTS Database•USDA PHZM•ASPCA
Frequently asked questions
Can I grow Royal Fern in my zone?
Royal Fern grows in USDA hardiness zones 4 through 10 (USDA PHZM 2023). Zone is one factor — soil pH, drainage, and frost dates on your specific parcel also shape whether it takes.
When should you plant Royal Fern?
Time royal fern to your own season rather than the calendar. Your local frost dates set the exact window — a Growable Ground report reads them for your address.
How much sun does Royal Fern need?
Royal Fern does well in partial sun — around 4 hours of direct sun, and it takes some afternoon shade in stride. That flexibility makes it a good match for a bed the house or a nearby tree shades for part of the day. A Growable Ground report maps how the sun actually falls on your land, hour by hour, so you can set it where the light lines up.
What soil does Royal Fern need?
Royal Fern prefers soil pH 4 to 6, on consistently moist ground (USDA PLANTS). Your report scores your parcel's actual soil against that using USDA SSURGO data.
Does Royal Fern attract pollinators?
Royal Fern isn't classified as a notable pollinator plant in our data. Pairing it with high-value bloomers nearby keeps bees and butterflies fed.
Is Royal Fern safe for pets?
Royal Fern is not known to be toxic to dogs or cats based on available data. Always supervise pets around new plantings. (Source: ASPCA.)