How to grow Tomato

Solanum lycopersicum

Many gardeners prune off the suckers as the plant grows — these are the vines that sprout from the crotch where a branch meets the main stem. Pruning the suckers is particularly important for indeterminate tomatoes, because it prevents them from growing unreasonably large, and directs more energy to the fruit.

Take care to avoid getting the leaves wet when you water the plant, as this can encourage fungal growth on the leaves.

When the plant flowers, some people find it is helpful to spray it with a dilute solution of epsom salts (1 tablespoon per gallon/4L of water), to provide a boost of magnesium, which helps the plant set fruit. The advisability of using any salt-based fertilizer is debated however.

If the plant’s leaves turn yellow, it may be that additional feeding is needed. You can side dress the plant with compost, or you can spray it with a dilute solution of fish emulsion or seaweed (mixed according to the package directions). If fish or seaweed is used, it should be sprayed on the leaves of the plant. Don’t touch the leaves after spraying, to avoid spreading any fungus to the plant. The plants should be fed no more than twice a month.

It is also helpful to spray the plant with diluted milk at least once during the growing season. Milk has natural anti-fungal and anti-mildew properties. Mix about 1 tablespoon of milk with 1 cup of water (you want about a 1:10 ratio of milk to water). Put the mix in a spray bottle and spray the leaves of the plant, making sure to get the undersides. This may be combined with feeding, and as with feeding, avoid touching the plant when the leaves are wet. This treatment can be repeated up to twice a month if fungus or mildew is a problem. Spoiled milk and powdered milk may be used.

If desired, in late summer you can also prune off branches that do not have flowers or fruit on them (do not do this in early summer, because flowers can emerge at any time). This puts the plant’s energies into the remaining flowers and fruit as the season comes to an end. If your plant still has unripe fruit on it 30-45 days before your first frost date, prune off all remaining flowers, and cut the plant off at about 5 feet from the ground. This will force the plant’s energies into the remaining fruit and give them a better chance of ripening on the vine before the frost.

The fine hairs along the stem of the tomato plant will grow into roots if they touch moist dirt. If you accidentally break a branch off, or even the whole stem, stick it back in the dirt and keep it moist. You may be able to save it! This is also how people can clone their plants to make more from a single planting.

Growing Tomato from seed

In most parts of the US and Europe, seeds must be started indoors because the growing season is too short for them to be started in the ground. Keep seedlings evenly moist and covered until they sprout.

Try to aim for a seed spacing of at least 0.78 inches (2.0 cm) and sow at a depth of around 0.39 inches (1.0 cm). Soil temperature should be kept higher than 12°C / 54°F to ensure good germination.

By our calculations*, you should look at sowing Tomato about 42 days before your last frost date .

Transplanting Tomato

Move seedlings to a bright light source as soon as they emerge from the starting mix. When the plant develops its first true-leaves, repot it in a larger pot to help it develop strong roots. Many gardeners repot it a second time before it is planted outside to help it grow even stronger roots.

Transplant out when it is at least 15cm (6 inches) high. Snip off the bottom set of leaves, and bury the plant up to the first remaining set of leaves. It will form roots all the way up the buried stem.

If cutworms are a problem in your area, make a cutworm collar out of an empty toilet paper roll.

Many gardeners provide extra fertilizer for the plant when it is planted. Some people use commercial fertilizers (organic or commercial) while others use fish heads, manure or other homemade and free sources.

Crushed egg shells in the hole may also be helpful, by providing the plant with extra calcium for fruit setting. Some people also add bonemeal or powdered milk to the hole (the milk provides calcium as well as some protection against fungal and mildew

Tomatoes require a minimum air temperature of at least 13C (55F), and a minimum soil temperature of 12C (53F). Do not plant out before these temperatures are reached. They can survive nighttime air temperatures as low as 7 C (45F) and soil temperatures as low as 10C (50F) but they will not grow until the soil has reached 13C (55F).

Ensure that temperatures are mild (minimum night temperatures should be around 13°C / 55°F) and all chance of frost has passed before planting out, as Tomato is a tender plant.

By our calculations*, you should look at planting out Tomato about 14 days after your last frost date.

Seed Saving Tomato

Pick fruits when they are ripe to overripe. Save seeds from several fruits.
To ensure germination of saved tomato seed, certain steps must be taken. The saving of tomato seeds is done through a fermentation process as the gel surrounding the seeds in the fruit is a growth inhibitor.
1. Take your seeds and place them in a plastic container. Fill with water and let sit in a warm, shaded area until a fine white mould starts to produce. This takes approx. 3-7 days.
2. Take a spoon, and scoop out all the mould after it appears, as well as any seeds that have floated to the top as these are dead seeds.
3. Strain the water out of the container, and rinse the seeds thoroughly.
4. Place the seeds on a non-stick surface (wax paper, butcher’s paper, or aluminum foil, do not use paper as the seeds will stick to this) and allow them to completely dry. This takes approx. 7 days.
5. After the seeds are thoroughly dried, place them in a seed packet, or bag – preferably paper. If placing in a plastic bag, add some desiccates to ensure that moisture does not become confined in the bag and cause the seeds to mould.

Seed viability is 5-10 years, depending upon storage conditions.

How long does Tomato take to grow?

These estimates for how long Tomato takes to sprout, grow and harvest are from real observations from real gardeners, right around the world.

Days to Germination How long does it take Tomato to germinate?
6 days

Average 6 days | Min 1 days | Max 15 days (5616)

Days to Transplant How long until I can plant out Tomato?
+ 51 days

Average 51 days | Min 1 days | Max 116 days (2873)

Days to Maturity How long until Tomato is ready for harvest / bloom?
+ 101 days

Average 101 days | Min 13 days | Max 192 days (8549)

Total Growing Days How long does it take to grow Tomato?
= 158 days

When should I plant Tomato?

Our when to plant Tomato estimates are relative to your last frost date.

When to sow The number of days to sow Tomato before or after your last frost date.
42 days before Last Frost Date
When to plant out The number of days to plant out Tomato before or after your last frost date.
14 days after Last Frost Date

Tomato Etymology

Our English name of “Tomato”, came originally from the Spanish “Tomate” who, on their voyages to North America, were the first to encounter this plant while making contact with the Aztecs. The original Nauhatl word (the language the Aztec people spoke) was “xitomatl”, which is where the Spanish got their word “tomate” from.

Tomato Folklore & Trivia

The tomato was long mistrusted when it was introduced to the Old World. It was often thought to be poisonous. One story is that in 1820, Colonel Robbert Gibbon Johnson announced that at noon on September 26 in Salem, New Jersey he would eat a bushel of the dreaded fruits. Two thousand people thought him mad and turned out to witness the event. To their astonishment, he survived. This story is most likely not true, but it illustrates the fears people had about tomatoes.

In the town of Buñol, Spain, a week-long festival featuring parades and fireworks called La Tomatina is held every year. During La Tomatina, tens of thousands of people participate in the world’s largest tomato fight. The tomato fight tradition began in either 1944 or 1945 but the reason it started has been lost to history. Possible reasons include a local food fight among friends, a juvenile class war, a volley of tomatoes from bystanders at a carnival parade, a practical joke on a bad musician, and an accidental spillage from a truck.

Other names for Tomato

Cherry tomato, Trailing tomato, Tomato

Lycopersicon lycopersicum, Lycopersicon esculentum, Solanaceae lycopersicon esculentum, Solanum lycopersicum var. grandifolium

Misspellings: Tomatoe, Tomatoes, Tomatos, Lycopersicon lypersicum, Love apple, Lycopersicon lycoprtsicum, Lycopersicon escultem


1 UC Davis Integrated pest management

2 “The New Seed-starters Handbook; Published 1988”

< Previous Plant Guide


Next Plant Guide >