In zone 9, plant tomato transplants outside from March 10 to March 17, one to two weeks after your last spring frost. Start seeds indoors from January 13 to January 27, and expect your first ripe tomatoes from about May 19.
Tomato dates for your ZIP code
Planting times based on university extension guidance (UNH, Cornell, Purdue, Minnesota, Nebraska and UMass Extension). Frost dates from NOAA 1991–2020 U.S. Climate Normals, nearest weather station. Zones derived from the 2023 USDA Plant Hardiness Zone Map data (PRISM Climate Group, Oregon State University). This is not the official USDA Plant Hardiness Zone Map.
Tomato timing in zone 9
| Task | When |
|---|---|
| Start indoors | January 13 – January 27 |
| Transplant outside | March 10 – March 17 |
| First harvest | May 19 – June 15 |
| Harden off seedlings | Over a few days to a week before transplanting |
| Stake or cage | At planting time |
| Plant a fall crop | Late summer, with heat-tolerant varieties |
Most of zone 9 sees its last spring frost between February 16 and March 15, with a typical date of March 3. Tomatoes are killed by frost, so if your last frost comes late, plant toward the end of the window. The tool above uses the weather station closest to your ZIP code.
Why tomatoes wait for warm weather
Tomatoes are warm-season plants. A frost kills them, and cold soil and cold nights stall their growth even without frost. They do best once the soil is at least 65 °F and the air at least 60 °F, which is why transplants go out one to two weeks after the last spring frost rather than on the frost date itself.
Best tomato varieties for zone 9
In zone 9, heat is the main challenge: tomato production usually slows or stops in the hottest part of summer. Plant early, and choose varieties that set fruit in heat:
- Heat-tolerant tomatoes: Heatwave, Sunmaster, Solar Fire, Solar Set and Mountain Spring.
- Cherry tomatoes keep producing longer in hot weather than most large slicers.
- Fast varieties (about 60 days or less) for the fall crop, so it ripens before your first freeze.
How to plant tomatoes
- Start seeds indoors about six to eight weeks before your transplant date, in soil kept at 60–70 °F.
- Harden off the seedlings by setting them outside for a few hours a day, increasing the time over several days.
- Plant deep. Set plants at the depth of their first leaves. Leggy seedlings can be laid at an angle, with only the top 5–6 inches above the soil.
- Space them out: 1–3 feet apart, or 12–18 inches for staked indeterminate plants.
- Add support right away. Use 6-foot stakes for indeterminate tomatoes and cages 4–5 feet tall for determinate ones.
- Feed lightly at planting with a starter fertilizer, and again with nitrogen once the first fruit sets.
Zone 9 tomato tips
- Plant as early as frost allows. The earlier your spring tomatoes set fruit, the more you harvest before summer heat stops them.
- Grow a second crop for fall. Many southern gardeners pull spring plants in July and set out new transplants in late summer for a harvest that lasts until the first freeze.
- Plan for the gap. Seeds take about four weeks to become transplants, and plants need another 8–10 weeks to produce. Start fall seedlings in early summer.
- Rotate. Moving tomatoes to a new bed each year reduces nematodes and soil diseases, which build up fast in warm soils.
- Water deeply and evenly. Uneven watering causes blossom end rot and cracked fruit, especially in heat.
Harvesting tomatoes
Pick tomatoes when they are fully colored, or when they are 60–90% colored and let them finish ripening indoors. Keep ripening and ripe tomatoes at 50–55 °F and out of the refrigerator, which ruins their flavor. When a frost is forecast, pick mature green fruit (the inside is filled with gel) and ripen it at 65–70 °F.
Tomato planting dates in nearby zones
- Zone 8April 7 – April 14
See dates for every zone on the tomatoes planting guide, or build a full schedule with the planting calendar.
Frequently asked questions
Is it too late to plant tomatoes in zone 9 in April?
For a spring crop, yes: plants set out that late flower in peak summer heat and set little fruit. Wait and plant a fall crop of heat-tolerant varieties in late summer instead.
Can I grow tomatoes in fall in zone 9?
Yes. A late-summer planting of fast, heat-tolerant varieties produces through fall until your first freeze, around November 25.
When should I start tomato seeds indoors?
About six to eight weeks before you plan to transplant. The dates above count back from your zone’s transplant window.
Can I plant tomatoes before the last frost?
Not without protection. Frost kills tomato plants, and cold soil slows them down even when it doesn’t freeze. Wait one to two weeks after your last frost date.
What is the difference between determinate and indeterminate tomatoes?
Determinate plants grow about 3–4 feet tall and ripen most of their fruit over a couple of weeks. Indeterminate plants can reach 7–8 feet and keep producing until frost.
Why are my tomato flowers falling off?
Usually because of temperature. Nights below 55 °F and very hot weather both cause tomatoes to drop flowers without setting fruit.
Sources. Planting dates use the median frost dates of each USDA zone, calculated from NOAA climate data for every ZIP code in the zone.