Plants · Flowers
Astilbe planting zones
Astilbe (Astilbe species and hybrids) is a perennial. By the type table below, at least one type lives through winter in the ground in 3a–9b; outside those zones, none of the types on this page is rated. Below the types are the dates its year turns on: each zone’s median last spring freeze and first fall freeze, from NOAA records.
Published October 26, 2026 · Cite this page
The types
Which astilbe to grow
| Type | Hardy in the ground | Notes |
|---|---|---|
| Hybrid astilbe Astilbe × arendsii (e.g. ‘Fanal’, ‘Bridal Veil’, ‘Rheinland’) | 3a to 9b, then too hot or humid | NC State rates it 3a to 9b and Clemson 3 to 9; Illinois says 4 to 9. Mostly early to midseason bloom (Iowa State). |
| Japanese astilbe Astilbe × japonica (e.g. ‘Deutschland’, ‘Montgomery’, ‘Red Sentinel’) | 4a to 8b, then too hot or humid | Iowa State lists ‘Deutschland’ as early and fragrant, ‘Montgomery’ midseason with dark foliage. |
| Chinese astilbe Astilbe chinensis (e.g. ‘Visions’, ‘Pumila’, ‘Purple Candles’) | 4a to 8b, then too hot or humid | The late bloomers on Iowa State’s list; ‘Pumila’ is a low groundcover type and ‘Purple Candles’ grows 36 to 42 inches. |
| Star astilbe Astilbe simplicifolia (e.g. ‘Sprite’, ‘Hennie Graafland’) | 4a to 8b, then too hot or humid | Small and late: Iowa State gives ‘Sprite’ 6 to 12 inches with dark bronze foliage. |
| Dwarf astilbe ‘Perkeo’ Astilbe crispa ‘Perkeo’ | 5a to 8b, then too hot or humid | Iowa State: 6 to 10 inches, rose flowers late, crisp foliage, zone 5 hardy. |
| Appalachian false goat’s-beard Astilbe biternata | 5a to 8b, then too hot or humid | The one astilbe native to North America (Clemson). NC State rates it 5a to 8b; it grows 3 to 6 feet in partial shade. |
Zone ranges are a judgement: horticultural convention set beside what the sources below say, not a measurement. In the next table the freeze dates are measured, and the count of hardy types comes from these judged ranges.
Zone by zone
Where astilbe lives through winter, and when the freezes fall
Each date is the median across every NOAA station the zone’s ZIP codes cite, 1991–2020 normals. The middle half of those stations falls within the range shown beside it.
| Zone | Types hardy in the ground | Last spring freeze | First fall freeze |
|---|---|---|---|
| 3a | 1 of 6 | only 10 stations with comparable freeze dates — too few to publish a date | |
| 3b | 1 of 6 | May 18 · middle half May 15 – May 25 | September 23 · middle half September 17 – September 26 |
| 4a | 4 of 6 | May 15 · middle half May 10 – May 21 | September 27 · middle half September 22 – September 30 |
| 4b | 4 of 6 | May 11 · middle half May 5 – May 23 | September 30 · middle half September 23 – October 3 |
| 5a | 6 of 6 | May 9 · middle half May 1 – May 20 | October 2 · middle half September 26 – October 7 |
| 5b | 6 of 6 | May 4 · middle half April 27 – May 15 | October 8 · middle half October 1 – October 14 |
| 6a | 6 of 6 | May 1 · middle half April 24 – May 9 | October 14 · middle half October 5 – October 20 |
| 6b | 6 of 6 | April 25 · middle half April 17 – May 3 | October 20 · middle half October 11 – October 24 |
| 7a | 6 of 6 | April 19 · middle half April 11 – April 27 | October 23 · middle half October 17 – October 28 |
| 7b | 6 of 6 | April 8 · middle half April 3 – April 16 | October 30 · middle half October 25 – November 3 |
| 8a | 6 of 6 | March 30 · middle half March 25 – April 5 | November 5 · middle half November 1 – November 10 |
| 8b | 6 of 6 | March 20 · middle half March 13 – March 29 | November 12 · middle half November 7 – November 18 |
| 9a | 1 of 6 | March 5 · middle half February 24 – March 15 | November 24 · middle half November 18 – December 2 |
| 9b | 1 of 6 | February 12 · middle half January 30 – February 25 | December 8 · middle half December 1 – December 17 |
| 10a | 0 of 6 | 107 of 190 stations here record no ordinary freeze, so there is no freeze date to count from | |
| 10b | 0 of 6 | 70 of 79 stations here record no ordinary freeze, so there is no freeze date to count from | |
| 11a | 0 of 6 | 34 of 34 stations here record no ordinary freeze, so there is no freeze date to count from | |
| 11b | 0 of 6 | 12 of 12 stations here record no ordinary freeze, so there is no freeze date to count from | |
“Types hardy in the ground” is a judgement, from the type table above. The freeze dates are measured.
A zone does not tell you your own dates. Inside a single zone the median last spring freeze still varies by 34 days from station to station, so the box below gives the dates of the NOAA station nearest your ZIP code.
Your ZIP code
Your ZIP, your answer
Enter your ZIP code to see your USDA zone, how many of the 6 types on this page live through that zone’s winter and when its freezes fall, read from the table on this page, and the freeze dates of the NOAA station nearest you.
Your answer appears here.
Full details for any ZIP code: ZIP code zone finder.
Which astilbe for your zone
NC State Extension’s plant toolbox rates hybrid astilbe zones 3a to 9b and Clemson’s Home & Garden Information Center zones 3 to 9; University of Illinois Extension says 4 to 9. Iowa State University Extension says astilbes are native to China, Japan and Korea, with hundreds of hybrids made from about a dozen species. Clemson says there is also one native to the southeastern United States, Appalachian false goat’s-beard (Astilbe biternata), which NC State rates zones 5a to 8b.
Iowa State sorts astilbes by bloom time: early types such as ‘Deutschland’ and ‘Peach Blossom’ flower in late May or June, late types such as the Chinese astilbes ‘Visions’ and ‘Purple Candles’ and the star astilbe ‘Sprite’ in late July or early August. Each blooms for 2 to 3 weeks, so planting several extends the display over 2 or 3 months. Heights run from 6 to 12 inches for ‘Sprite’ and ‘Perkeo’ to 4 feet for ‘Purple Lance’. Iowa State calls ‘Perkeo’ zone 5 hardy.
Shade, and where they will take sun
Iowa State says astilbes grow best in part shade and can do well in full shade with fewer flowers; they tolerate full sun only with abundant moisture. Clemson and NC State say the same: shade, or more sun if the soil stays moist. Illinois warns that dry, sunny sites give poor foliage and few flowers.
Soil, water and mulch
Iowa State calls fertile, moist, humus-rich soil a must, and says astilbes are unforgiving in dry soil, where the leaves brown quickly. It also says they do not tolerate waterlogged or heavy clay soil well, and improves clay or poorly drained ground with peat moss, compost or other organic matter before planting. NC State wants soil that is organically rich and well-drained.
Clemson waters regularly to get plants established and deeply and consistently in the hottest months, because the leaf edges turn brown if the plant dries out and the foliage may go dormant in drought. NC State says the same: in hot summers or drought the foliage may decline if the soil is not kept moist.
Feeding: Illinois calls astilbes heavy feeders; Iowa State adds compost or organic matter around the base every year for more blooms and healthy foliage; Clemson uses an all-purpose fertilizer when needed.
Supplies
Supplies the sources mention
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- CompostIowa State says annual additions of compost around the base of the plant are rewarded with more blooms and healthy foliage.
- Soaker hosesClemson waters astilbe deeply and consistently in the hottest months, because the leaf edges brown if the plant dries out.
- Shredded bark mulchIowa State says to water and mulch well after dividing astilbe to help the divisions establish.
Dividing astilbe
The sources give different intervals. Illinois says astilbes benefit from dividing every 3 years; Clemson every three to four years, if needed, in early spring or fall; NC State about every 4 years, preferably in spring or fall; and Iowa State every 4 to 6 years for vigorously growing plants. Iowa State divides large clumps in early spring as the foliage emerges, and waters and mulches well afterward to help the divisions establish.
Fall: leave the plumes standing
Astilbes are one of the perennials the sources leave up for winter. Iowa State says to allow a few spent flower plumes to remain in fall for their brown spikes through much of the winter, and NC State that the spent flowers and seed heads are ornamental through fall and winter. Clemson cuts back the previous year’s leaves in late winter, before the new growth emerges.
Common problems
NC State says hybrid astilbe has no serious insect or disease issues; possible pests are whitefly, Japanese beetle and black vine weevil, and possible diseases powdery mildew, wilt, bacterial leaf spot and Cercospora leaf spot. Clemson names Japanese beetles, powdery mildew and wilt. The most common problem in all three is dry soil: brown leaf edges and declining foliage.
NC State says hybrid astilbe is resistant to rabbits and deer, and Appalachian false goat’s-beard is deer and rabbit resistant and tolerates black walnut.
Common mistakes
- Planting in a dry or sunny spot. Illinois says it gives poor foliage and few flowers, and Iowa State that the leaves brown quickly in dry soil.
- Letting it dry out in summer. Clemson waters deeply and consistently in the hottest months.
- Heavy clay or waterlogged soil. Iowa State says astilbes do not tolerate either well.
- Cutting the plumes off in fall. Iowa State and NC State leave them for winter interest.
We found no Florida, Texas, Louisiana or Alabama source for astilbe that we could read; Texas A&M AgriLife, LSU AgCenter and Alabama Extension did not load from here. Southern advice on this page comes from South Carolina and North Carolina only.
Questions
- Why are my astilbe leaves turning brown?
- Usually dry soil. Clemson says the leaf edges turn brown if the plant dries out, Iowa State that astilbes are unforgiving in dry soil, and NC State that the foliage declines in hot, dry weather if the soil is not kept moist.
- Should you cut back astilbe in the fall?
- The sources leave it up. Iowa State keeps a few spent plumes for winter interest, NC State says the seed heads are ornamental through winter, and Clemson cuts the old leaves back in late winter before new growth.
- When do you divide astilbe?
- Clemson divides in early spring or fall every three to four years; NC State about every 4 years in spring or fall; Iowa State in early spring as the foliage emerges, every 4 to 6 years. Illinois says every 3 years.
- Can astilbe grow in full sun?
- Only with moist soil. Iowa State and Clemson say astilbes tolerate more sun if the soil stays moist; Illinois says dry, sunny sites give poor foliage and few flowers.
Sources
Freeze dates on this page are NOAA 1991–2020 Climate Normals, for every station the ZIP codes in each zone cite. Zones are the USDA Plant Hardiness Zone Map, 2023. The type table is a judgement, as labelled above. Growing advice is quoted from the extension publications below, each written for its own area.
- Iowa State University Extension and Outreach, Growing Astilbe in Iowa (Last reviewed June 2024). Written for: Iowa (USDA zones 4b–6a).
- University of Illinois Extension, False Spirea . Written for: Illinois (USDA zones 5a–7a).
- Clemson Cooperative Extension, Home & Garden Information Center, How to Grow and Care for Astilbe , by Ginger Elizabeth Long . Written for: South Carolina (USDA zones 8a–9b).
- NC State Extension Gardener Plant Toolbox, Astilbe × arendsii (hybrid astilbe) . Written for: North Carolina (USDA zones 6b–9a).
- NC State Extension Gardener Plant Toolbox, Astilbe biternata (Appalachian false goat’s-beard) . Written for: North Carolina (USDA zones 6b–9a).
Published October 26, 2026
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