How to Grow Tomatoes: A Beginner’s Guide

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How to Grow Tomatoes: A Beginner’s Guide

Tomatoes are one of the most popular crops for home gardeners, and it’s not hard to figure out why: few things compare to the taste of your own home-grown tomatoes. Whether you plant them in a garden bed, container, or even indoors, growing tomato plants can be super rewarding.

In this guide, I’ll break down everything you need to know about planting tomatoes, keeping them healthy, and dealing with a bunch of common problems. This will be your hub for tomato care tips, organized into sections for outdoor gardens, container gardening, and indoor growing. Before you start, though, make sure you know what tomato variety to pick for your needs!

Outdoor Tomato Gardening: The Traditional Method

Planting Tomatoes

Tomato plants thrive in full sun, so pick a sunny spot that gets at least 6–8 hours of sunlight daily. Next, you’ll need to prepare the soil. Use well-drained soil rich in organic material, like compost or peat moss. Test your garden soil for a pH of 6.2–6.8, which is what works best for tomatoes.

In almost every case, it’s better to start tomato seeds indoors and transplant them once they’re at least 6 inches tall. You can also purchase started tomatoes from a nursery. Transplant these young tomato plants (seedlings) after any danger of frost has passed in late spring.

How to Plant

Start by digging a deep hole, burying the plant up to the first set of leaves. This encourages new roots along the buried stem, creating a stronger root system and helping with the plant’s stability. Space plants 18–24 inches apart for good air circulation, which helps prevent fungal diseases.

For more details, visit the complete guide to transplanting tomatoes.

Watering and Feeding

Tomatoes are heavy feeders, so they need consistent nutrients and water. Watering can be tricky, so I’ve written a whole post on how often to water that includes the best techniques.

Plan to feed your plants every couple of weeks with a balanced fertilizer—look for one labeled 10-10-10 or 5-10-5, which provides an even mix of nitrogen (for leafy growth), phosphorus (for roots and flowers), and potassium (for overall health and fruit production). If you’re using liquid fertilizer, apply it directly to the base of the plant after watering to prevent root burn. For a more organic option, you can mix compost tea or fish emulsion into your watering routine.

In addition to fertilizer, adding a small pinch (about a teaspoon per plant) of Epsom salt to the soil every few weeks can help provide magnesium, which supports chlorophyll production and fruit development. Dissolve it in water or sprinkle it around the base of the plant, then water it in. Just be careful not to overdo it—too much magnesium can throw off your soil’s nutrient balance.

Supporting Your Plants

Tomato plants come in two main types: determinate and indeterminate.

Determinate tomato plants, sometimes called ‘bush’ tomatoes, grow to a certain height—usually around 3 to 4 feet—and then stop growing. They tend to produce most of their fruit over a short period (usually a few weeks), making them great for gardeners who want a big harvest all at once, like for canning. These types usually don’t require much pruning and can often get by with minimal support, like a short cage or small stake.

Indeterminate tomato plants, on the other hand, keep growing taller and producing fruit until the first frost hits. Some can grow over 6 feet tall! They need strong support, like a tall tomato cage, sturdy stakes, or even a trellis.

Because they grow and produce over the whole season, it’s helpful to prune off small shoots (called suckers) that appear between the main stem and the branches. This helps the plant focus its energy on growing fruit instead of too much leafy growth. (Here’s how to prune your tomatoes.)

Container Gardening: Tomatoes for Small Spaces

Growing tomatoes in containers is a good idea if you have limited space or want more control over your soil and water. I’ve written a complete guide to growing tomatoes in containers, but here are a few basics to get you started:

Choosing the Right Container & Potting Soil

For most regularly sized tomato varieties, use large containers (at least 5 gallons) with good drainage holes. Pot material isn’t that important for the plants themselves – pick the kind that works best for your needs. Plastic pots are lightweight and mobile, while terracotta pots can help with water retention in hot weather.

Use a high-quality vegetable potting mix with added compost or organic matter. Avoid garden soil, which is too compact and prevent the roots from growing properly.

Watering and Fertilizing in Containers

Container-grown tomatoes dry out faster, so check the soil surface daily and water deeply when the top inch feels dry. You can also add a slow-release fertilizer when planting or feed regularly with a liquid fertilizer.

Indoor Tomato Gardening: Year-Round Growing

Want fresh tomatoes in the middle of winter? With the right setup, you can grow tomatoes indoors.

Getting Started Indoors

To start, choose compact or dwarf tomato varieties labeled as good for indoor growing—these stay smaller and are easier to manage under lights or in a sunny window. Use a large container (at least 3–5 gallons) with good drainage holes to give your plant enough room to grow. Fill the container with a high-quality potting mix that includes compost or other organic matter.

Sow seeds about 1/4 inch deep, or use healthy starter plants. If using seeds, keep the container in a warm spot (70–80°F) until they germinate. Use a heat mat if needed.

As your plant grows, move it into larger containers if needed to prevent root crowding. Support the plant with a small cage or stake. Water whenever the top inch of soil feels dry, and feed it regularly with a balanced liquid fertilizer or one formulated for fruiting plants.

Lighting Needs

Tomatoes are heat-loving plants that need lots of light to thrive. South-facing windows that received 6-8 hours of sun are ideal. If natural light is limited, use a grow light to provide 12–16 hours of light per day. Adjust the light to stay 2–3 inches above the plants as they grow.

Pollination Indoors

Since you won’t have bees to pollinate indoor tomatoes, shake the plant gently or use a small brush to transfer pollen between flowers.

Common Tomato Problems and Solutions

Tomatoes are prone to a few common problems, but with quick action, you can save your plants:

1. Blossom End Rot
Cause: Calcium deficiency due to inconsistent watering.
Fix: Water regularly and evenly. Add crushed eggshells or a calcium supplement to the soil.

2. Early Blight and Late Blight
This is a pretty complicated but common issue for tomatoes – I’ve written a full guide specifically for tomato blight identification and fixes.

3. Tomato Fruitworm
Cause: Pests that burrow into fruits.
Fix: Inspect plants regularly and use organic pest control methods, like neem oil.

4. Cracked Fruit
Cause: Irregular watering or sudden rain after a dry spell.
Fix: Keep watering consistent, especially during fruit development. Mulch can help hold in moisture.

5. Yellowing Leaves
Cause: This could be from overwatering, nutrient deficiency, or lack of sunlight.
Fix: Check drainage, use a balanced fertilizer, and make sure plants are getting 6–8 hours of sun.

Harvesting Ripe Tomatoes

The best time to pick tomatoes is when they’re firm, fully colored, and slightly soft to the touch. For indeterminate varieties, keep harvesting to encourage new fruiting. Ripe tomatoes usually pull easily from the vine—if they don’t, use scissors to avoid damaging the plant.

End of the Growing Season

In late summer or before the first frost, harvest any green tomatoes. You can ripen them indoors on a windowsill or use them in recipes like fried green tomatoes. If frost is close, pull the entire plant and hang it upside down indoors to let remaining fruit ripen gradually.

Enjoy Your Tomatoes!

Growing tomatoes takes some hard work, but the payoff is worth it when you bite into a sun-warmed, juicy tomato fresh off the vine. Whether you’re planting in a garden bed, container, or indoors, follow these step-by-step instructions for the best results. To learn even more, check out 35 Tips for Growing Tomatoes.

Wondering what to plant near tomatoes? Check out the full list of tomato companion plants, and find out why tomatoes and marigolds go well together!