Growing Tomatoes From Seed

Reading Time: 11 minutes


The perfect tomato, ripe and still warm from your home garden, can be eaten right out of hand, perhaps with a sprinkle of salt. If you care about the quality of food, you’ve no doubt discovered that tomatoes purchased from supermarkets are a poor substitute for the real thing. Artificially ripened, they are mushy, pulpy, and lacking flavor. Fortunately, real tomatoes are extremely easy to grow, even if you’ve never tried your hand at growing vegetables before.

Whether you’re new to gardening or have gardened a bit and are a “green thumb” but would like to try something new, growing tomatoes from seed is a great way to dig in. You don’t need any particular expertise or ability, nor do you need special equipment. All you need is some interest, a bit of time, a laptop for buying seeds, or a garden center and a sunny window with space for a few small tomato seedlings inside, or a small sunny plot outside.

Of course, you can always purchase tomato plants from a nursery to plant directly into your garden, and there is nothing wrong with that approach. However, if you grow your tomatoes from seed, you’ll save money, have a far greater selection of tomato varieties to choose from, and have a deeper connection with your plants and the food they produce. There is a great deal of satisfaction that comes from producing your own food from start to finish, particularly these days when self-sufficiency has renewed appeal.

Growing Tomatoes-How Do You Get Started? Step By Step Guide

growing tomato plants from seed how to get started

Item Checklist:

Before you start sprinkling tomato seeds everywhere, there are a few things you need. Your heirloom tomato varieties seed starting kit should include:

  • Open Pollinated Heirloom Tomato seeds
  • High-Quality Organic potting mix or seed starting mix-Avoid using garden soil when seed starting. Use a seed starting mix or soil that is sterilized. Plain old garden soil may contain harmful pathogens or lack essential plant nutrients. 
  • Small container or Growing trays- A Biodegradable tray is the absolute best because you don’t need to pull your tomato seedling when transplanting; you simply place the whole trays into the soil. Alternatively, you can use egg carton paper, plastic cups, or plastic containers.
  • Spray bottle- A glass or metal spray bottle is more sustainable, but if you don’t have one on hand, you can repurpose an empty household bottle. Just make sure to pick one that never contained harsh chemicals, as the residue can damage your delicate baby plants.
  • Plant markers- Popsicle sticks make great plant markers. These markers are like name tags for your plants, which comes in handy when you’re planting different varieties. Plastic markers are ok because you can reuse them. If you’re only planting one type of seed, they’re not necessary.
  • Optional items-Grow lights & Heat Mats- If you choose to grow year round indoors opt for grow lights or an artificial light. I recommend a 54W high output with T5 fluorescent lights and a bulb life of 20,000 hours. This is a small investment for many years of healthy tomato seedlings. A heat mat may or may not be optional depending on your setup

With heirloom tomato varieties, start with good-quality heirloom seeds. While you may be tempted by seed displays at the supermarket, you’ll find a greater selection and better quality tomato seeds if you look a bit further. Locate a well-stocked store online that offers a wide selection of seeds and helpful advice for beginning gardeners. Once you start looking you’ll realize that there are many varieties of tomatoes to choose from.

Here’s what you need to know. Tomatoes come in two types: 

Determinate tomato plants

indeterminate tomato plants

Most heirloom tomatoes are indeterminate. These grow large and sprawling and produce tomatoes throughout the season right into the fall until a hard frost kills them. Determinate varieties tend to be compact bushy plants that set fruit all at once so that you’ll harvest a crop of tomatoes within a short period. This information can help you choose what type of tomato to grow. How do you plan to use the tomatoes you grow? Do you want fresh tomatoes for summer salads? Would you like large juicy tomatoes for slicing and grilling? Do you prefer small flavorful plum tomatoes to use in sauces? Or are you hoping to put up jars of tomato sauce in the fall? Whatever you prefer, there is the perfect tomato for you.

Local knowledge can be very helpful when deciding which varieties to grow. Ask a local gardener, or the staff at your garden supply center to help narrow your choices. After all, a tomato that thrives in Georgia may not care for the weather in Maine! Ask what types of tomatoes do best where you live. You will undoubtedly hear about popular varieties such as Big Boys, Celebrities, Ace 55, Juliets, Tip Tops, Early Girls, or Beefsteaks. Any of these are great choices.

growing at least two varieties of tomatoes from seed

Seasoned gardeners will tell you that some years are great tomato years and other years not so much for plant growth. An entire region of tomato growers may have a disappointing season. But oddly enough, young plants may be overcome by weather conditions or blight, while a different tomato variety growing right alongside it will flourish and produce good fruit. So hedge your bets with at least two different types.

growing tomatoes from seeds indoors cherry tomatoes and heirloom tomatoes

Tomato Seeds in Hand,
You Are Ready To Plant And Grow Your Own Tomatoes

The best growing season for heirloom tomatoes is summers, if you notice on your seed packet it is recommended to start your tomato seeds 4-6 weeks before the average last frost date. Tomatoes are a tender plant. They thrive in warm temperatures, and cannot tolerate frost. Most heirloom tomatoes need at least 8 hours of sunlight or a grow light if you are growing indoors to bear fruit and good air circulation. Tomato varieties unlike house plants need a stable, moderately warm environment, constant soil temperature for healthy plants to grow. Ideally, If you live in a warm climate, you can start tomato seeds outside in your vegetable garden as soon as the soil is warm and there is no danger of frost. Many gardeners get a head start on the growing season in cooler climates by starting seeds inside, about six to eight weeks before the last frost date. If you’re unsure about your last frost date, find out online here.

Growing Tomatoes From Seed

Starting Tomato Seeds Outside

Starting tomato seeds indoors is a great option with many vegetables, however, tomato seeds need constant soil temperatures around 60 degrees, preferably 80 degrees for successful germination. Success with tomato plants is all about l In temperate climates, it’s more of a challenge because the soil will reach ideal temperatures only around mid-summer which is too late for tomatoes.

  • Choose a sunny location to plant your tomato seedlings. A south-facing plot with good drainage is best or in larger containers.
  • Make sure that your soil is loose and well worked to a depth of one foot.
  • Add compost to the soil and mix it in well.
  • Sow seeds at a depth of 1/3 of an inch, about 6 inches apart, in rows two feet apart.
  • Cover seeds with soil and pat the soil down firmly to encourage good contact between seed and soil.
  • Make sure to water daily as seeds cannot tolerate drying out.

Tomato seeds germinate in about one to two weeks, depending on the weather. Be patient. When tomato seedlings are about three inches high, thin them so they are two feet apart on all sides. When thinning pull out the smallest plants, allowing the sturdiest to remain.

growing tomatoes from seeds indoors

Starting Seeds Indoors

You can either plant tomato seeds in a flat, or tray, paper cups or plant seeds individually in small pots or a small container. Either way, if you use peat pots your work is greatly simplified. You’ll find peat pots, also called jiffy pots, in most garden supply stores. Very inexpensive, they make tomato transplants a snap. When it’s time to replant the entire pot can be planted. It then decomposes into nice crumbly peat that enriches the soil. This eliminates shocking tender roots during the transplant. Peat pots come in many sizes. Start with the smallest pots, about 2 inches high, at about 5 cents apiece. 

You’ll also need:
A bag of potting soil mix. Potting mix soil is recommended because it is a perfect lightweight mixture rich in nutrients, which optimally supports germination and the development of a root system.
Jiffy pellets are also great for starting seeds. These are flat discs the size of silver dollars, which when soaked in water expand to a couple of inches in size and already include a nice peaty seed starting mix. You simply soak, let it expand, and you’re ready to plant.

  • Fill each pot with potting add soil and give each a thorough soaking. It’s fine if you are using improvised containers (such as milk cartons cut in half) or egg cartons as long as you make sure each container has drainage holes in the bottom for successful germination.
  • Level the soil off and place two to three seeds in the soil each seed about 1/3 of an inch deep. You can poke a depression in the soil with your finger and drop each seed in.
  • Gently sprinkle soil over the seed and press it down firmly to make sure the seed has good contact with the soil on all sides to prevent fall-overs just or just in case you get leggy seedlings.
  • Label each container with a waterproof marker.
  • Cover containers with a plastic bag or plastic wrap and secure them for a greenhouse effect. The plastic creates a mini greenhouse, keeping the soil moist while the seeds germinate.

Less frequent watering…You won’t need to water again until you see the first green shoots emerging from the soil. If more than one seed germinates you can use them as cuttings.

Until your seeds have sprouted, they shouldn’t be in a sunny location just at warm room temperature. Direct sunlight could cause the soil to dry out or trap soil moisture, causing the seed to rot. Instead, choose a warm location away from drafts.

grow tomatoes from seed

Once your baby tomatoes sprout, remove the plastic covering and move them into a sunny window ledge so the plants grow upright, preferably one with southern exposure and good overhead natural sunlight to avoid “legginess.” Legginess is when tomato plants grow long and spindly because they are trying to reach the best light source, with grow lights this can be avoided by placing the light overhead. 

Now you must water daily… Be careful with tender seedlings when watering. It is difficult to pour water over a delicate seedling without knocking it down. 

The best method is to use a spray bottle in the mist setting for moisture just not soaking wet. Each day check the soil with your fingertip. It should be just at the point of being not moist. If it is damp, wait for a while before you water. If it is very dry, you need to water your plants regularly and more frequently. 

Mist the soil thoroughly. It should feel completely moistened, but not soaked. Make sure to use warm room temperature water so you don’t shock the roots. If it’s cold at night, move the seedlings away from drafty windows. Tomato seedlings grow quickly, but like any newborn, they need a little coddling.

transplanting heirloom tomato plants

After a few weeks, you can begin to add fertilizer to your seedlings once per week, following the directions on the package. 

Two or three weeks after sprouting you’ll have vigorous plants that are about three inches tall. These should be transplanted into a bigger pot (ceramic or plastic pots are will do fine) or if growing tomatoes indoors to a soilless potting mix which will encourage the development of a healthy root system. Choose a pot that’s about twice the size of the one you started with, or about 4 inches deep.

Pinch off the lowest leaves and plant the tomato an inch or so deeper in the soil this time. The section of stem that is now under the soil will begin to grow roots soon. Remember that if you are using peat pots simply plant the entire pot. If using another type of container, tip the plant upside down, supporting the plant with one hand while gently tapping the bottom of the pot. The soil will slide out and you can carefully place the roots with their covering of soil into the new container. Be extremely gentle when handling roots. 

Tomato Gardening Tips: Expect your plant to look slightly shocked for a day or so, but unless it gets horribly jostled, it should soon recover.

Tomatoes can stay in their second pot until they are about 10 inches tall. When they reach this height, if it’s not time to put them outside yet, you should transplant them again into a larger pot of about 6 inches in depth. Again, pinch off the bottom leaves and this time set the roots at the bottom of the pot. The root system will continue to develop and you’ll have a sturdy plant with a strong stem.

transplant your tomatoes outside

When the ground has warmed you can get ready to transplant your tomatoes outside, in a large container garden, balcony garden, or raised bed garden. About a week before transplanting, you need to harden your tomatoes off. Hardening off is a process of getting the plants acclimated to being outside. Start by setting them out for a few hours at a time in the moderate sun and bring them in at night. Morning sun is a good choice, as opposed to the brightest noonday sun. Each day, increase the time that plants spend outside. Watch them carefully to make sure they’re not overwhelmed by the elements. Also, make sure to give them a thorough watering before they are set out. 

By the end of a week, you’ll be able to set your plants out for most of the day, without them looking wilted or burned.

When it is time to transplant tomatoes to the garden, prepare the soil line in advance the same way that you would if planting seeds directly outside. Dig a hole deep enough to set plants an inch deeper than they were in their pots. Leave two feet of space around each plant. Pinch off the bottom leaves on that part of the stem that will be covered by soil. Set the tomato into the ground, and gently cover the roots over. Gently pat the soil firmly around the plant, ensuring that the tomato is snug in its bed.

Growing Tomatoes From Seed

Tomatoes need to be staked or caged to grow straight and upward to prevent overwatering and plant diseases that can be found in the soil. The best time to do this is directly after planting them. While they are small they don’t need the support of a stake, but if you wait until they’re larger, you risk harming the roots. 

Use stakes about 4 feet high, and set them within a few inches of each plant. When the plant starts to grow healthy tomatoes and becomes heavy with fruit, you’ll gently tie it to the stake to help support its branches.

Water tomatoes daily early or late in the day, when water can soak into the soil Midday when the sun is hottest, much water is lost to evaporation. Also, stay alert to the weather. 

Tomato Gardening Tips: If there is a cold snap after your tomatoes have been set out in the garden, you’ll need to protect them from frost by covering them at night. A sheet, blanket, or tarp will do the job nicely.

The Wrap Up...

While gardeners always find tasks to keep them busy, getting plants started and into the garden is the lion’s share of the work, at least until harvest time. At a certain point, nature takes over and does what it is so good at doing: producing abundant juicy tomatoes bursting with flavor makes for happy gardening. Many gardeners take special pleasure to care for the baby tomato plants they started from seed. You will enjoy a completely reciprocal relationship with those plants. The time and attention that you spend taking care of them is returned to you in the form of delicious, sun-ripened, home-grown tomatoes. Get the salt shaker out, wander out to the garden, and enjoy….Happy Gardening!

*Keep in mind to give you the most all-inclusive content possible and how-to guides that we may occasionally use affiliate links in which we receive commissions when you click the links and make purchases. However, this does not impact our content or establish bias. We try our best to keep things as informational as possible in order to help you grown the plants, flowers, herbs and vegetables of your dreams.

More Posts You May Like

Share The Knowledge


Do You Want The Latest Exclusive Content and Savings Delivered?

Enter Your Email Address Here​

Wordpress Social Share Plugin powered by Ultimatelysocial
Naturezedge Natural Garden Supplies
We use cookies to give you the best online experience. By agreeing you accept the use of cookies in accordance with our cookie policy