Plants · Flowers
Zinnia planting dates by zone
Zinnia (Zinnia elegans and hybrids) is an annual, so your zone does not decide whether it survives the winter. The dates do. The table below counts each planting date for every zone from its median freeze dates in NOAA records, by a rule a named source states.
Published October 24, 2026 · Cite this page
The types
Which zinnia to grow
| Type | Examples | Notes |
|---|---|---|
| Tall cutting zinnias | ‘Benary’s Giant’, ‘State Fair Mix’, ‘Oklahoma’, ‘Queeny’ | Long stems for bouquets. Wisconsin says ‘Oklahoma’ and ‘State Fair Mix’ tolerate powdery mildew. |
| Dwarf bedding zinnias | ‘Thumbelina’, ‘Magellan’, ‘Dreamland’, ‘Short Stuff’ | Under about 15 inches, for edging and containers (UF/IFAS, Wisconsin). |
| Hybrid zinnias (marylandica) | ‘Profusion’, ‘Zahara’, ‘Zydeco’ | Bred for heat and disease resistance. Texas A&M says marylandica types are highly resistant to powdery mildew and last until frost. |
| Narrowleaf (creeping) zinnia | ‘Crystal’, ‘Star’ series | Low and spreading. UGA calls creeping zinnia a reliable annual for hot, dry areas. |
None of these types is rated by zone, because each is grown for one season; the notes are the sources’, not a ranking. The planting rules in the next table are a judgement or a source’s rule, and the dates they are counted from are measured.
Zone by zone
When to plant zinnia in each zone
Each date is the median across every NOAA station the zone’s ZIP codes cite, 1991–2020 normals.
| Zone | Start indoors | Sow or plant out from | Safer in 9 years of 10 | First fall freeze ends it |
|---|---|---|---|---|
| 3a | only 10 stations with comparable freeze dates — too few to publish a date | |||
| 3b | April 6 – April 20 | May 18 | May 31 | September 23 |
| 4a | April 3 – April 17 | May 15 | May 29 | September 27 |
| 4b | March 30 – April 13 | May 11 | May 26 | September 30 |
| 5a | March 28 – April 11 | May 9 | May 24 | October 2 |
| 5b | March 23 – April 6 | May 4 | May 19 | October 8 |
| 6a | March 20 – April 3 | May 1 | May 16 | October 14 |
| 6b | March 14 – March 28 | April 25 | May 11 | October 20 |
| 7a | March 8 – March 22 | April 19 | May 5 | October 23 |
| 7b | February 25 – March 11 | April 8 | April 25 | October 30 |
| 8a | February 16 – March 2 | March 30 | April 16 | November 5 |
| 8b | February 6 – February 20 | March 20 | April 8 | November 12 |
| 9a | January 22 – February 5 | March 5 | March 28 | November 24 |
| 9b | January 1 – January 15 | February 12 | March 12 | December 8 |
| 10a | 107 of 190 stations here record no ordinary freeze, so there is no freeze date to count from | |||
| 10b | 70 of 79 stations here record no ordinary freeze, so there is no freeze date to count from | |||
| 11a | 34 of 34 stations here record no ordinary freeze, so there is no freeze date to count from | |||
| 11b | 12 of 12 stations here record no ordinary freeze, so there is no freeze date to count from | |||
- Start indoors: four to six weeks before the median last spring freeze (Wisconsin).
- Sow or plant out from: the median last spring freeze, after the danger of frost has passed (Wisconsin, UF/IFAS).
- Safer in 9 years of 10: the date the last spring freeze falls before in nine years of ten (NOAA).
- First fall freeze ends it: the median first fall freeze; UGA says zinnias are not frost-tolerant, and UF/IFAS that healthy plants bloom often until the first frost.
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, the planting dates for that zone, 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.
Choosing a zinnia
University of Wisconsin–Madison Extension says zinnias range from 8 inch mounds to 3-4 foot plants, with single, double or semi-double flowers including dahlia, cactus and crested forms. It says they thrive in hot, dry conditions, attract butterflies, resist deer damage, and that the taller types are excellent cut flowers. UF/IFAS Gardening Solutions says they come in pretty much every color except blue.
Disease resistance is the other choice. Wisconsin says the Zinnia marylandica hybrids, such as ‘Profusion’ and ‘Zahara’, combine strong heat tolerance, drought tolerance and disease resistance, and that ‘Oklahoma’ and ‘State Fair Mix’ tolerate powdery mildew. NC State Extension says to plant disease-resistant varieties in hot, humid climates.
Sowing and planting out
Wisconsin says annual zinnias can be sown directly in the garden after the danger of frost has passed, or started indoors 4 to 6 weeks earlier. UF/IFAS says to plant after the last frost date, and NC State to sow seed directly after the last frost date. The table above gives both dates for your zone.
UF/IFAS’s zinnia fact sheet says the seeds are usually sown directly in the garden, because seedlings started indoors become spindly, especially if started too early. It spaces plants 8 to 12 inches apart, and Gardening Solutions says to give them space because crowding encourages disease. Zinnias need full sun and well-drained soil (UF/IFAS, NC State); Clemson’s Home & Garden Information Center says they may get more leaf spot in partial shade.
Care
UF/IFAS says tall varieties may be pinched when young to encourage branching, and old flowers removed to keep the plants blooming. Texas A&M AgriLife’s Brent Pemberton says the standard types can be pinched for bushiness, but the newer marylandica types do not need it.
Water at the base of the plant. Clemson says keeping the leaves dry discourages bacterial and fungal disease, and that overhead watering should be done in the early morning so the leaves dry quickly; UF/IFAS also says to keep water off the leaves in humid Florida. UF/IFAS says zinnias are drought-tolerant once established but thrive with regular watering.
Cutting zinnias for bouquets
UF/IFAS says zinnia bouquets can last at least a week, and that leaving enough stem with leaves on the plant when you cut brings a new bloom soon after. UGA Extension’s cut-flower guide says zinnias have very good vase life if cut just after opening, and do well with frequent cutting: “Spare the clippers, spoil the Zinnia.”
Southern timing
UF/IFAS says zinnias can be planted in spring throughout Florida and also in the fall in South Florida, and its fact sheet says from August to September in southern Florida; healthy plants bloom through the summer, often until the first frost. In Texas, Texas A&M AgriLife Today reports that fall zinnias usually reach garden centers in September and tolerate Texas heat well, showing color until the first frost if properly watered and fertilized. Larry Stein, in Uvalde, says it is not too late in May to sow zinnia seed directly.
UGA says zinnias grow well under hot, sunny conditions but need ample moisture, and calls creeping zinnia a reliable annual for hot, dry areas. NC State says zinnias may slow down at the peak of summer.
Common problems
Clemson names the diseases: powdery mildew, a grayish-white powdery coating; Alternaria leaf spot, small dark reddish spots that grow and turn gray in the center; bacterial leaf spot, small purplish angular spots; Cercospora leaf spot; and aster yellows, carried by leafhoppers, which deforms the flowers and has no control. It says to rotate zinnias with other bedding plants for a year or two, remove plant debris at the end of the season, and not save seed after a leaf spot outbreak, since infected seed carries the disease.
Clemson says aphids, spider mites and whiteflies may damage zinnias in hot, dry weather, that aphids and mites can be hosed off, and that because zinnias feed many beneficial insects, insecticides other than insecticidal soap are not recommended. UF/IFAS adds the four-lined plant bug, which causes small, round, brown sunken spots.
NC State Extension’s plant toolbox lists zinnia as non-toxic for cats, dogs and horses, and says deer do not find it appetizing.
Common mistakes
- Starting seed indoors too early. UF/IFAS says the seedlings become spindly.
- Crowding the plants. UF/IFAS says crowding encourages disease.
- Watering the leaves late in the day. Clemson says wet leaves overnight invite leaf spot and mildew.
- Planting in part shade. Clemson says zinnias are more prone to leaf spot there.
- Saving seed from diseased plants. Clemson says infected seed carries leaf spot.
We found no Louisiana or Alabama source for zinnias that we could read; LSU AgCenter and Alabama Extension did not load from here. The Southern timing on this page is UF/IFAS’s, Texas A&M AgriLife’s and UGA’s.
Questions
- When should I plant zinnia seeds?
- Wisconsin sows them outdoors after the danger of frost has passed, or starts them indoors 4 to 6 weeks earlier; UF/IFAS and NC State plant after the last frost date. The table on this page gives both dates for each zone from NOAA records.
- How do I stop powdery mildew on zinnias?
- Clemson says to water at the base so the leaves stay dry, and Wisconsin to space plants for air circulation and grow resistant varieties such as the marylandica hybrids, ‘Oklahoma’ or ‘State Fair Mix’.
- Should I pinch zinnias?
- UF/IFAS says tall varieties may be pinched when young to encourage branching. Texas A&M AgriLife says the newer marylandica types do not need it.
- How long do zinnias last in a vase?
- UF/IFAS says zinnia bouquets can last at least a week, and UGA says they have very good vase life if cut just after opening.
- Can I plant zinnias in the fall?
- In South Florida, yes: UF/IFAS says from August to September. Texas A&M AgriLife Today reports that fall zinnias reach Texas garden centers in September and bloom until the first frost.
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 planting rules are named beside the table. Growing advice is quoted from the extension publications below, each written for its own area.
- University of Wisconsin–Madison Extension, Zinnias (Revised May 6, 2026). Written for: Wisconsin (USDA zones 4a–6a).
- UF/IFAS Gardening Solutions, Zinnia (Accessed October 2026). Written for: Florida (USDA zones 8b–11b).
- UF/IFAS EDIS, Zinnia elegans: Zinnia (FP623) , by Edward F. Gilman, Teresa Howe, Ryan W. Klein and Gail Hansen (Accessed October 2026). Written for: Florida (USDA zones 8b–11b).
- NC State Extension Gardener Plant Toolbox, Zinnia elegans . Written for: North Carolina (USDA zones 6b–9a).
- Clemson Cooperative Extension, Home & Garden Information Center, Zinnia Insect Pests & Diseases (HGIC 2110) , by Barbara H. Smith (Updated October 11, 2022). Written for: South Carolina (USDA zones 8a–9b).
- Texas A&M AgriLife Today, New and old fall zinnias named Texas Superstars (August 22, 2014). Written for: Texas (USDA zones 6b–10b).
- Texas A&M AgriLife Extension Service (Texas A&M Stories), How to keep your garden colorful through the summer (May 8, 2023). Written for: Texas (USDA zones 6b–10b).
- UGA Cooperative Extension, Flowering Annuals for Georgia Gardens (B954) , by Bodie V. Pennisi (Published with minor revisions May 11, 2026). Written for: Georgia (USDA zones 7b–9a).
- UGA Cooperative Extension, Some of Georgia’s Best Cut Flowers , by Paul A. Thomas (March 5, 2026). Written for: Georgia (USDA zones 7b–9a).
Published October 24, 2026
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