Tomatoes on a vine

How To Grow Tomatoes From Seed To Harvest.

Fresh tomatoes are a staple of many summer meals especially when they are fresh and homegrown. Tomatoes are one of the easiest and most rewarding crops to grow. Whether you grow them only to eat them fresh, or if you plan to can or freeze. Growing tomatoes from seed is a rewarding experience that can provide you with fresh, juicy tomatoes all season long. Whether you’re a seasoned gardener or a beginner, this guide will tell you everything you need to know to grow the best tasting tomatoes you’ve ever had.

This post contains affiliate links. If you use these links to buy something we may earn a commission. Thanks.

Choosing Your Tomato Seeds

Seed Packets of tomatoes

The first step in growing tomatoes from seed is to choose the right variety of tomato seeds. There are hundreds of different tomato varieties to choose from, each with its own unique flavor, texture, and growing requirements. Consider factors such as determinate vs indeterminate, the size of the plant, the colour and size of the fruit, the expected harvest quantity, and the time to maturity when selecting your tomato seeds.

We grow a wide variety of tomatoes at our house. We have 2 varieties of determinate, but most are the indeterminate variety. I personally like indeterminate tomatoes the best because they will keep growing until the weather gets to cold for them. I’ll go through the benefits of both:

  • Determinate: Have a predetermined size and will grow to that size and stop. Our 2 determinate varieties are Roma (for making pasta sauce with) and a new variety this year called Bonsai cherry tomato. The benefit of determinate and the reason we have that variety for making sauce with is that the fruits will all ripen at approximately the same time. Making it much easier to harvest and use them when making big batches of canned goods.
  • Indeterminate: Like I said above will keep producing new fruit until the weather gets to cold that it kills the plant. Last year we grew tomatoes in our greenhouse from the end of March to mid November. Another benefit of indeterminate tomatoes is the opposite of determinate, the fruit doesn’t ripen all at once. We like this because it creates a steady stream of constantly ripening tomatoes all season long.

Starting Your Tomato Seeds

Tomatoes being planted in soil blocks

To start your tomato seeds, you will need a few basic supplies, including seed-starting trays or pots, and a sterile seed-starting mix. Optional items are a soil blocker and a heat mat. Fill your trays or pots with the seed-starting mix, and then sow your seeds according to the package instructions. Cover the seeds with a thin layer of soil, and then water them lightly.

Place the trays or pots on a heat mat or in a warm, sunny location to encourage germination. Keep the soil moist but not saturated, and monitor the seedlings closely for signs of growth. To help with germination a humidity dome can also be used to help keep the soil moist. If you do use a dome make sure as soon as you see germination you remove the dome to prevent mold.

Transplanting Your Seedlings

Tomatoes being planted showing strong root development.

Seedlings can be transplanted outside once the danger of frost in your location has past, typically called the last frost date. For us in zone 5b that is May 7th. But we typically wait and watch the weather to make sure it’s safe to transplant. Once your tomato seedlings have grown to about 3-5 inches in height, they are ready to be transplanted into larger pots or outside in the garden. Use a high-quality potting soil, and plant your seedlings deep enough to cover the bottom set of leaves.

Tomato Seedling recently planted into a garden bed.

Tomatoes have a unique root system that will grow from any part of the stem that is buried in soil. By planting your seedlings deep, you will encourage strong, healthy roots and a sturdy stem.

Caring for Tomatoes

As your tomato plants continue to grow, they will need proper care and maintenance. Be sure to water your plants regularly, keeping the soil evenly moist but not waterlogged. Tomatoes are heavy feeders and will benefit from regular applications of a high-quality tomato fertilizer.

Additionally, you may need to provide support for your tomato plants as they grow taller. Staking, trellising, or using cages are all effective methods of supporting tomato plants and preventing them from toppling over. Indeterminate varieties can get very tall and heavy. We’ve had some of ours get to about 10 feet tall. I use T posts hammered into the garden soil and use the weave method to keep my plants upright.

Showing the tomato trellising style called Florida Weave
Florida Weave technique to support tomatoes.

The Florida Weave method consists of using string or twine to weave in and out between your tomato plants. Going all the way down from one side of the garden to the other and then back again. Pulling the string taught so that it’s rigid. As the plant grows you add another string a little farther up the posts near the top of the plants and repeat.

As well as support, your tomato plants will also need to be pruned on a regular basis to promote the best yield from each plant. There are 2 types of pruning you will need to do. Removing suckers, and removing leaves.

Holding tomato sucker at junction of main stem and leaf.
Holding tomato sucker at junction of main stem and leaf.
  • Why and how to remove suckers: Suckers are new branches that form at the cross section of the main stem and leaf branches. Each sucker is basically an entire new tomato plant. If left to grow the sucker will grow like the main stem and form flowers, leaves, and even more suckers. We remove these to let the plant focus its energy on the main stem and fruit production. To remove them use clean pruning shears or simply pinch them off with your thumb.
  • Why and how to remove leaves: The entire idea about removing leaves from the tomato plant is to provide better airflow. Airflow is essential to prevent mold and also because tomatoes self pollinate from the wind. So the more airflow the easier they will pollinate. I don’t prune any leaves until the plant has its first set of flowers, or if any leaves are touching the ground. Then I use clean shears and simply cut the leaf branch off close to the main stem being careful not to damage the plant.

Using these pruning techniques once every week or two will help the fruit production and overall health of your tomato plants.

Harvesting Tomatoes

Ripening tomatoes on a vine.
Ripening Tomatoes, Big Mama variety.

As your tomato plants mature, you will start to see ripe, juicy tomatoes forming on the vine. Tomatoes can be harvested at any point once they start changing colour. The sooner your pick the tomato, the longer it will stay fresh when stored. Simply twist or cut the stem at the base of the tomato, and it will come off the vine easily.

Tomatoes can continue to ripen off the vine, so you can leave them at room temperature to ripen further. However, be sure to keep an eye on them to prevent over-ripening or spoilage.

In conclusion, growing tomatoes from seed to harvest is a fun and rewarding experience that can provide you with fresh, delicious tomatoes all season long. With the right seeds, proper care and maintenance, and a little patience, you can enjoy a bountiful tomato harvest in your own backyard. We have more growing guides for you to enjoy and we are adding more all the time.

Scroll to Top