Silky Oak is a tree, a long-term addition to the landscape. It's hardy across USDA zones 9 through 11. Its summer flowers are a real draw for honeybees, native bees, and hummingbirds. It roots deep, which helps it reach moisture in a dry spell and open up tight soil as it establishes.
Silky Oak — the short answer
Silky Oak: grown in zones 9–11, full sun, pH 4.5–7.5.
- USDA zones
- 9–11
- Hardy to zone 9 — USDA PLANTS Database (17 °F, converted).
- Soil pH
- 4.5–7.5
- FAO ECOCROP
- Sun
- Full Sun
- Converted from FAO ECOCROP
- Frost-kill temp (growing season)
- 30.2°F
- FAO ECOCROP
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 Silky Oak on your exact land.
Zone averages can't see the slope, soil, frost, and sun that decide whether silky oak actually takes — and those shift from one yard to the next. Enter your address and we'll score silky oak against your land's real conditions.
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What Silky Oak is
Silky Oak grows as a perennial and reaches around 105 feet at maturity. It blooms yellow in summer.
How to grow Silky Oak
Silky Oak grows in USDA zones 9 through 11. Silky Oak does best in full sun — at least 6 hours of direct sun a day — and soil from pH 4.5 to 7.5, on well-drained ground.
USDA Zones
9-11
Hardy to zone 9: USDA PLANTS Database lists 17 °F, converted to zone 9a, checked Oct 2026. Ceiling: our plant database.
Soil pH
4.5 - 7.5
FAO ECOCROP
Sun
Full Sun
Converted from FAO ECOCROP
Drainage
well (dry spells)
FAO ECOCROP
Frost Kill Temperature
30.2°F
Where cold starts killing growing tissue. Not a winter-survival floor — a dormant perennial takes far colder, which its hardiness zone answers.
FAO ECOCROP
Minimum Growing Temperature
46.4°F
Below this it stops growing rather than dies — a pace limit, not a survival limit.
FAO ECOCROP
Mature Height
105 ft
USDA NRCS PLANTS Database
Plant it right
Set silky oak in full sun with well-drained soil.
Match the soil
Silky Oak prefers pH 4.5 to 7.5 (FAO ECOCROP). 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. A 2–3 inch mulch layer holds moisture without waterlogging.
Shape it while it is young
Prune silky oak only to remove dead, damaged or crossing branches while it is young; it is grown for its form, not a harvest, so little more is needed once it settles in.
Where Silky Oak thrives
Silky Oak is hardy across USDA zones 9 through 11. 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 9–11 spans average winter lows from 20°F to 50°F (USDA PHZM 2023). Across the 50 states and DC, that band covers none outright but splits 17 down the middle — and which side of that line your land sits on changes the answer.
Zones 9–11·Where Silky Oak growsOpen map →
This map is derived from the USDA ARS / PRISM Plant Hardiness Zone Map (2023) and is not the official USDA Plant Hardiness Zone Map.
Where Silky Oak stands, state by state
Silky Oak is rated for zones 9–11 — a cold floor USDA puts at 20 to 30°F. Across the 50 states and DC, 0 sit fully inside that band, the line runs through 17 more, and 34 sit outside it — and inside every split state, the same line runs on at county grain.
The line runs through
17 states
- Alaska · zones 1a-9a
- California · zones 4b-11a
- Nevada · zones 4a-10a
3 of 17 shown
Silky Oak’s band covers part of each of these states — which side of the line your county sits on changes the answer, and each state page draws it.
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 Silky Oak
Growing guides for silky oak
Good to know
One caution for pet owners — silky oak is toxic to dogs and cats (mild severity). Keep it out of reach, and call ASPCA Animal Poison Control at (888) 426-4435 in an emergency. (Source: Cornell Poisonous Plants Database.)
Silky Oak is a standout pollinator plant — high value to bees and other pollinators. We haven't confirmed this against a published source yet.
Your land is one point inside Silky Oak'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 Silky Oak will thrive on your land
Zone averages are a start. Your soil pH, drainage, sun exposure, and frost dates shape whether silky oak actually takes. We score it against the mapped and modelled 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.
25+ data sources analyzed in seconds
How we know this about Silky Oak
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
Frequently asked questions
Can I grow Silky Oak in my zone?
Silky Oak grows in USDA hardiness zones 9 through 11 (Hardy to zone 9: USDA PLANTS Database lists 17 °F, converted to zone 9a, checked Oct 2026. Ceiling: our plant database.). Zone is one factor — soil pH, drainage, and frost dates on your specific parcel also shape whether it takes.
When should you plant Silky Oak?
Set silky oak out in early spring or fall while it's dormant, so the roots establish before the heat of summer. Your local last-frost date — which a Growable Ground report pulls for your exact address — sets the precise window.
How much sun does Silky Oak need?
Silky Oak needs full sun — a spot that catches at least 6 hours of direct summer sun a day. We haven't confirmed this against a published source yet. In more shade it still grows, but usually gives a smaller, later crop. The catch is that a yard rarely gets even light everywhere — a fence, the house, or one tall tree can quietly take those hours. A Growable Ground report reads the real sun-hours across your land, canopy and buildings included, so you can pick the brightest bed before you plant.
What soil does Silky Oak need?
Silky Oak prefers soil pH 4.5 to 7.5, on well-drained ground (FAO ECOCROP). Your report scores your parcel's mapped soil against that using USDA SSURGO data.
Does Silky Oak attract pollinators?
Yes — silky oak's flowers are a strong nectar and pollen source for honeybees, native bees, and hummingbirds. We haven't confirmed this against a published source yet.
Is Silky Oak safe for pets?
Silky Oak is toxic to dogs and cats with mild severity. Keep it out of reach, and call ASPCA Animal Poison Control at (888) 426-4435 in an emergency. (Source: Cornell Poisonous Plants Database.)
Keep exploring Silky Oak
Silky Oak state by state
Every state silky oak's zone reaches — 3 link straight to that state's silky oak growing page; the rest open the state's full growing guide.