It’s common to put off starting seeds indoors or to forget to pick up tomato plants at the garden center to get into the ground, but when is it too late to plant?
When you select the right varieties of tomatoes, you can plant them two to six weeks later than usual and still have time for them to grow, mature, and produce juicy ripe tomatoes.
In this guide, I explain the best month and time of day to plant tomatoes and how late you can sow tomatoes and have them mature before the weather cools. Planting tomatoes later in the season is absolutely possible, but timing is everything.
How Late Can You Plant Tomatoes?
You can plant tomatoes 2-6 weeks later than usual and still achieve a successful harvest.
One issue with planting your tomatoes late is the possibility that your plants will come into flower at the hottest part of the summer.
While tomatoes grow well in warmer weather, several days in a row of extreme heat over 90ºF will trigger the plant’s natural survival instincts.
This trait means that any flowers you were hoping to turn to fruit will likely not happen, as the plant feels it cannot sustain the energy burden of producing fruit.
Certain varieties, such as Solar Set, and Heat Wave II, are very heat tolerant and perfect for gardeners in the south.
If you’re planting seeds late in your garden and think you’ll encounter hot conditions, you should pick tomato plants developed for hot weather and also try to shade your plants at the peak heat of the day.
You may also need to help pollinate your tomato plants if they grow in humid weather conditions. Pollen will stick to the male section of the flower and not fall onto the female part, so a little intervention with a pollinator brush is worth the effort.
As most tomato plants take around 100 days from seed to harvest, you may encounter another issue: losing fruit due to early cold snaps.
If you are behind on your garden schedule, consider choosing tomato varieties that mature much quicker than standard ones.
In terms of timing from seed to table, here are the best tomato varieties for late planting:
- Subarctic
- Sophie’s Choice
- Bush Beefsteak
- Gardener’s Delight
- Manitoba
- Silvery Fir Tree
- Cold Set
- Tigerella
Subarctic tomatoes can be ready for harvest in as few as 42 days, making them the fastest producers on this list. Sophie’s Choice tomatoes take on average 55 days until the first crop is ready.
All the other tomato plants on this list average 55-65 days until harvest, which should give gardeners late to the game a chance to enjoy a summer or early fall crop.
Choose Seedlings Instead Of Seeds
If you’re late in starting your garden, buying and setting tomato seedlings or plants from a garden center can shave off 2-3 weeks of growing time versus growing a tomato plant from seed.
You may have difficulty acquiring good-quality tomato seedlings later in the season, as most of the stock sells off as soon as the soil is warm enough to grow tomatoes.
What remains may not be in the best shape as the small growing pot may be crowding the plant’s root system.
When To Plant Tomatoes
Ideally, the best time to plant tomatoes is when the soil temperature reaches 60ºF and nighttime temps remain above 50ºF.
The timing to reach these temperatures will vary depending on where you live, but most will find tomato planting can begin in late April or May in the north and as early as February in the south.
Ensure you leave enough of a buffer to avoid losing newly-sprouted tomato seedlings to a late freeze after the “safe” last-frost date in your area. If you plant seeds in a location with full sun exposure all day, you can warm plant sprouts and help them survive.
If nighttime temperatures remain cool at night well into the growing season, there’s no need to plant tomato seeds early.
Tomato plants that mature too quickly won’t form flowers to set fruit if it’s colder than 55ºF at night. Keep this timing in mind when you sow seeds or buy seedlings for your garden.
Spring is the season to plant most tomato seeds in any USDA Planting Zone 1-9.
If you live in Zone 10, which includes South Florida, Hawaii, and lower California, you can plant tomatoes in late summer or early fall and have fruit before the coldest days of winter set in.
Best Time Of Day To Plant Tomatoes
When you are planting seeds, you can put them in the ground at any time of day as long as the soil is warm enough to trigger germination.
For tomato seedlings, the best time of day to plant them in your garden is in the early morning, when the sun’s rays are less intense.
If you can give your plants a few hours to adjust to their new environment before harsh sun exposure, they will do better.
Another good time of day to plant tomatoes is when it’s cloudy or overcast. The clouds will buffer your new plants from the excessive heat of the direct sun that can quickly dry out tender seedlings.
Don’t plant seedlings in the evening. The cooler night air and heavier moisture may shock the plant, causing it damage.
If you must plant tomato seedlings at the hottest time of the day, try to protect your plot with some shade cloth for the first few days.
Giving the plants a break from too much heat gives the roots a chance to establish themselves in the new environment. Remove the shade cloth after several days and watch to see if the tomato plants are strong enough to handle direct sunlight.
If you witness the tomato plant wilting or having curling, dry leaves, water the soil well. Use the shade cloth only at midday until they perk up.
