When to Plant Begonias in USDA Zone 9b
Wax begonias (Begonia × semperflorens) are the workhorse shade bedding plant of American horticulture, offering continuous bloom from transplant to hard frost. Bronze or green-leaved varieties perform well from deep shade to full sun (in northern zones) and tolerate summer humidity better than most cool- season flowers. A staple of mass plantings, containers, and window boxes.
In Zone 9b, the average last spring frost is around January 25 and the first fall frost is around December 20, giving you a growing season of approximately 329 days.
Begonias Planting Timeline — Zone 9b
Where Is USDA Zone 9b?
The map below highlights the states that contain Zone 9b. Click any state to see the Begonias planting schedule for that location.
Begonias Planting Calendar — Zone 9b
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | November 16 | Nov 16 – Nov 30 |
| Transplant Outdoors | December 28 | Dec 28 – Jan 11 |
| Bloom | March 8 | Mar 8 – Sep 20 |
· 8" apart · Rows 10" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Transplant Outdoors |
| February | — |
| March | Bloom |
| April | Bloom |
| May | Bloom |
| June | Bloom |
| July | Bloom |
| August | Bloom |
| September | Bloom |
| October | — |
| November | Start Indoors |
| December | Transplant Outdoors |
Free Zone 9b Planting Calendar PDF
Know exactly when to plant every crop in your zone. Get a printable month-by-month calendar customized for Zone 9b with start dates, transplant windows, and harvest times.
Growing Conditions
Sun
Partial Shade (3-6 hours)
💧 Water
Moderate — regular watering
Days to Maturity
70–90 days
Soil pH
5.5 – 6.5
Zone Temperature Range
25°F to 30°F average annual minimum
Growing Season
329 days (Zone 9b average)
Planting Specifications
| Plant Spacing | 8 inches apart |
| Row Spacing | 10 inches between rows |
Succession Planting Begonias in Zone 9b
Sow every 8 weeks for continuous harvest throughout the season.
Growing Tips for Begonias in Zone 9b
Zone 9b offers a long growing season (~329 days). You can plant Begonias earlier and may get multiple harvests.
Start seeds indoors 10–12 weeks before last frost — seed is dust-fine; surface-sow on moist mix under lights, do not cover. Bottom heat (70–75°F) speeds germination. Transplant after frost; begonias are not direct-sown in practice. Pinch seedlings once for branching. Keep soil evenly moist; avoid waterlogged conditions. Bronze-leaf types tolerate more sun; green- leaf types prefer shade to part-sun.
Companion Planting
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Saving Begonias Seeds
Recommended for Your Garden
Reduce heat stress and sun scorch in hot climates with UV-stabilized shade cloth.
Start seeds indoors with reusable cell trays and humidity domes.
Test your soil pH, nitrogen, phosphorus, and potassium levels before planting.
Related Plants
Begonias in Other Zones
Begonias by State
- Alabama
- Alaska
- Arizona
- Arkansas
- California
- Colorado
- Connecticut
- Delaware
- Florida
- Georgia
- Hawaii
- Idaho
- Illinois
- Indiana
- Iowa
- Kansas
- Kentucky
- Louisiana
- Maine
- Maryland
- Massachusetts
- Michigan
- Minnesota
- Mississippi
- Missouri
- Montana
- Nebraska
- Nevada
- New Hampshire
- New Jersey
- New Mexico
- New York
- North Carolina
- North Dakota
- Ohio
- Oklahoma
- Oregon
- Pennsylvania
- Rhode Island
- South Carolina
- South Dakota
- Tennessee
- Texas
- Utah
- Vermont
- Virginia
- Washington
- West Virginia
- Wisconsin
- Wyoming
Frequently Asked Questions
When should I plant Begonias in Zone 9b?
In Zone 9b, plan your Begonias planting around the average last frost date of January 25. Start seeds indoors around November 16. Transplant seedlings around December 28.
Can Begonias grow in Zone 9b?
Yes, Begonias can grow well in Zone 9b, hardy in USDA zones 2a through 11b. Zone 9b has a growing season of approximately 329 days, which is sufficient for Begonias (70-90 days to maturity).
When can I harvest Begonias in Zone 9b?
In Zone 9b, expect to harvest Begonias from March 8 – September 20. Begonias takes 70-90 days from planting to harvest.
What is the last frost date for Zone 9b?
The average last spring frost in Zone 9b is around January 25, and the first fall frost is around December 20. This gives a growing season of approximately 329 days. These are 50% probability dates — actual frost dates vary year to year.
What should I plant next to Begonias?
Good companion plants for Begonias include Impatiens, Lobelia, Sweet Alyssum, Ferns. These companions can help with pest control, pollination, and nutrient sharing.
Your Zone 9b Garden Planner — Free
A 22-page printable planner tailored to Zone 9b. Planting dates, monthly task lists, harvest log, seed inventory, and succession charts — everything you need to plan a full season.