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Ripe red tomatoes on a vine with green leaves with the text "easy guide to growing San Marzano tomatoes.

Growing San Marzano Tomatoes in Your Backyard: Sweet Success

If you love tomatoes, you probably have heard of San Marzano tomatoes. Chefs use these prized tomatoes to make authentic Italian sauces, soups, and pizzas. They are long and red with a unique taste that no other tomato has.

But did you know that you can grow your own San Marzano tomatoes in your backyard? Growing San Marzano tomatoes is rewarding and beneficial for your health and the environment. You can enjoy fresh, organic, and delicious tomatoes that are free of pesticides and chemicals. You can also reduce your carbon footprint by avoiding transporting and packaging store-bought tomatoes.

In this blog post, we will guide you through the steps of growing San Marzano tomatoes in your backyard, from getting started to harvesting and beyond. We will also share some tips and tricks to overcome common challenges and ensure a sweet success.

Getting Started: Steps of Growing San Marzano Tomatoes

Before you plant your San Marzano tomato, you need to decide whether you want to start from seeds or buy seedlings. Both options have their pros and cons, so let’s compare them.

Separate images showcasing tomato seeds in a packet and healthy seedlings in a tray.

Seeds vs. Seedlings

  • Seeds: Starting from seeds gives you more control over the quality and variety of your tomatoes. You can choose organic, heirloom, or non-GMO seeds that suit your preferences. You can also save money by buying seeds in bulk and storing them for future use.

However, starting from seeds requires more time and effort. You need to sow the seeds indoors 6 to 8 weeks before the last frost date and then transplant them outdoors when the weather is warm enough. You also need to provide adequate light, water, and temperature for the seeds to germinate and grow.

  • Seedlings: Buying seedlings from a local nursery or garden center saves you time and hassle. You can skip the indoor sowing and transplanting process and directly plant the seedlings in your garden. You can also choose healthy and vigorous plants that are ready to grow.

However, buying seedlings limits your choices of tomato varieties. You may not find the exact San Marzano tomatoes you want. Instead, you might end up with hybrid or GMO plants that do not match the original type. You also need to check the plants for any signs of pests or diseases before you buy them.


The timing of planting your San Marzano tomatoes depends on your climate and the method you choose. If you start from seeds, you need to sow them indoors 6 to 8 weeks before the last frost date in your area.

You can use a seed tray, a peat pot, or a small container with drainage holes. Fill it with a good potting mix and moisten it lightly.

Place 2 to 3 seeds per cell or pot, and cover them with a thin layer of soil. Keep the tray or pot in a warm and sunny spot, such as a windowsill or under a grow light.

Water the seeds regularly, but do not overwater them. The seeds should sprout within 7 to 10 days.

If you buy seedlings, you need to wait until the danger of frost has passed and the soil temperature is above 60ยฐF. You can use a soil thermometer to check the temperature or follow the local planting calendar for your area.

You can also harden off the seedlings before planting them outdoors. This means gradually exposing them to outdoor conditions for a few hours a day for a week or two. This will help them adapt to the sun, wind, and temperature changes.

Choosing a Locationย 

The location of your garden is crucial for the success of your San Marzano tomatoes. Tomatoes are sun-loving plants that need at least 6 to 8 hours of direct sunlight per day. Choose a spot that is sunny, sheltered, and well-drained. Avoid areas that are shaded, windy, or soggy.

You can also improve the soil quality by adding organic matter, such as compost, manure, or mulch. This will help retain moisture, improve drainage, and provide nutrients for your plants.

Planting and Care For Growing San Marzano Tomatoes

Once you have prepared the seeds or seedlings and the location, you are ready to plant your San Marzano tomatoes. Here are some detailed instructions on how to do it.

Planting Instructions

  • Dig a hole for each plant that is twice as wide and deep as the root ball or the peat pot.
  • If you are planting seeds, gently remove the seedlings from the tray or pot and separate them carefully. If you are planting seedlings, gently squeeze the peat pot to loosen the soil and the roots. You can also cut off the bottom of the peat pot to allow the roots to grow freely.
  • Place one plant per hole, and bury the stem up to the first set of leaves. This will help the plant develop a strong and deep root system. You can also pinch off the lower leaves to prevent diseases and pests.
  • Space the plants about 2 to 3 feet apart and the rows about 4 to 5 feet apart. This will allow enough room for air circulation and growth.
  • Water the plants well after planting, and add a layer of mulch around the base to conserve moisture and prevent weeds.

Supporting the Plants

San Marzano tomatoes keep growing and producing fruits until frost kills them because they are indeterminate plants. They can grow up to 6 feet tall or more, and they need support to prevent them from falling over and breaking. There are different ways to support your tomato plants, such as staking, caging, or trellising. Here are some pros and cons of each option.

  • Staking: Staking involves driving a wooden or metal stake into the ground next to each plant and tying the main stem to the stake with a soft material, such as twine or cloth. You need to stake the plants when they are young and keep tying them as they grow. Staking keeps the plants upright and tidy and allows more sunlight and air to reach the fruits. However, staking requires more pruning and maintenance and can limit the yield and size of the fruits.
  • Caging: Caging involves placing wire cages around plants to support growth and reduce the need for pruning and tying. However, it can lead to overcrowding and block sunlight and air from reaching lower parts of the plant.
  • Trellising: Trellising is when you make a structure with poles, wires, or strings for plants to grow on. You can use fences, and walls, or make your own with bamboo, wood, or metal. You need to start trellising plants when they are young and keep tying them to the structure as they grow. Trellising helps plants spread out and grow better, using space efficiently. But it can be hard and take time, and the fruits may get damaged by the sun or birds.

Watering and Feeding

Watering and feeding your San Marzano tomatoes are essential for their health and productivity. Here are some tips on how to do it right.

  • Water your plants deeply and infrequently rather than shallowly and frequently. This will encourage the roots to grow deeper and stronger and prevent diseases and cracking.
  • Aim for about 1 to 2 inches of water per week, depending on the weather and the soil. You can use a rain gauge, a moisture meter, or your finger to check the soil moisture.
  • Water the plants early in the morning or late in the evening, and avoid wetting the leaves and the fruits. Use drip irrigation or a soaker hose to water plants at the roots, saving water by avoiding evaporation and runoff.
  • Feed your plants with a balanced fertilizer or a tomato-specific formula that contains nitrogen, phosphorus, and potassium. You can use organic or synthetic fertilizers, granular or liquid forms, or slow-release or fast-acting types. Follow the instructions on the label for the amount and frequency of application. You can also supplement your plants with compost, manure, or other organic amendments to provide additional nutrients and improve the soil quality.
  • Feed your plants when you transplant them and then every 2 to 4 weeks during the growing season. Stop feeding your plants when they start to ripen, as this will improve the flavor and quality of the fruits.


Pruning your San Marzano tomatoes is optional, but it can help improve the health and yield of your plants. It involves removing some of the leaves, branches, or suckers from your plants to direct the energy and resources to the fruits. Here are some benefits and drawbacks of pruning.

  • Benefits: Pruning can increase the air circulation and sunlight exposure of your plants, which can reduce the risk of diseases and pests. Pruning can also increase the size and quality of the fruits, as the plants can focus on producing fewer but better fruits. Pruning can also make the plants easier to manage and harvest, especially if you are using stakes or cages for support.
  • Drawbacks: Pruning can stress the plants and make them more susceptible to sunscald and drought. Sunscald is a condition where the fruits get burned by the sun due to the lack of foliage protection.

Drought is a condition where the plants lose more water than they can absorb due to the high temperatures and low humidity. Pruning can also reduce the yield of your plants, as you are removing some of the potential fruits. Pruning can also expose the wounds of your plants to infections and diseases.

Common Challenges

Growing San Marzano tomatoes is not without its challenges. You may encounter some pests and diseases that can affect the health and yield of your plants. You may also face some issues like blossom end rot that can ruin the quality of your fruits. Here are some common challenges and how to deal with them.


Some of the pests that can attack your tomatoes are aphids, whiteflies, spider mites, hornworms, and cutworms. These pests can suck the sap, chew the leaves, or bore into the fruits of your plants. They can also spread viruses and bacteria that can cause diseases. To prevent and control these pests, you can use the following methods:

  • Monitor your plants regularly and remove any pests by hand or with a blast of water.
  • Use natural pesticides like neem oil, insecticidal soap, or diatomaceous earth to protect your plants from pests. Follow the instructions on the label and avoid spraying during the heat of the day or when the plants are wet.
  • Introduce beneficial insects to your garden, such as ladybugs, lacewings, or parasitic wasps. These insects can prey on the pests and reduce their population.
  • Plant companion plants near your tomatoes, such as basil, marigold, or garlic. These plants can repel or distract the pests and attract the beneficial insects.


Some of the diseases that can affect your San Marzano tomatoes are blight, wilt, mosaic, and spot. These diseases can cause the leaves, stems, or fruits of your plants to turn yellow, brown, or black and eventually die. They can also reduce the flavor and quality of the fruits. To prevent and control these diseases, you can use the following methods:

  • Choose disease-resistant varieties of San Marzano tomatoes, or look for the letters V, F, N, T, or A on the seed packets or plant labels. These letters indicate the resistance to verticillium wilt, fusarium wilt, nematodes, tobacco mosaic virus, or Alternaria leaf spot, respectively.
  • Practice crop rotation and avoid planting tomatoes in the same spot for more than 3 years. This will help reduce the buildup of pathogens in the soil.
  • Avoid overhead watering and water the plants at the base. This will prevent the spread of spores and bacteria from the soil to the plants.
  • Remove and dispose of any infected plants or parts as soon as you notice them. Do not compost them, as this can contaminate your compost pile and spread the disease.
  • Use organic or natural fungicides, such as copper, sulfur, or baking soda, to spray or dust your plants. Follow the instructions on the label and apply them before the disease appears or at the first sign of infection.

Blossom End Rot

Blossom end rot is a common disorder that affects San Marzano tomatoes and other tomato varieties. A lack of calcium in fruits causes dark, sunken, and rotten spots at the blossom end. Irregular watering, high temperatures, or root damage can also trigger it. To prevent and treat blossom end rot, you can use the following methods:

  • Maintain a consistent and adequate watering schedule for your plants. Water them deeply and infrequently, and avoid letting the soil dry out or get waterlogged.
  • Cover your plants with straw, grass clippings, or leaves. This will help keep the soil moist and at a steady temperature. Using organic materials is beneficial for your plants. It is a simple way to protect them from harsh weather conditions.
  • Add lime, gypsum, or eggshells to your soil to increase the calcium level and the pH. You can also use a calcium-rich fertilizer or a foliar spray to supplement your plants with calcium.
  • Harvest and discard any affected fruits as soon as you notice them. Do not eat them, as they may taste bitter and have a poor texture.

Harvesting and Beyond

After months of growing and caring for your San Marzano tomatoes, you can finally enjoy the fruits of your labor. Here are some tips on how to harvest and store your tomatoes and how to use them in various ways.


A red ripe San Marzano tomato is ready to be harvested.

You can harvest your San Marzano tomatoes when they are fully ripe and have a deep red color. You can also gently squeeze the fruits and feel for a slight give. The best time to harvest is in the morning or evening when the fruits are cool and firm. To harvest your tomatoes, you can use the following methods:

  • Cut or twist the fruits from the vine, leaving a short stem attached. This will prevent the fruits from bruising and cracking.
  • Place the fruits in a single layer in a basket or a tray. Do not stack them, as this can cause pressure and damage.
  • Avoid washing the fruits until you are ready to use them. Washing them can remove the protective coating and make them spoil faster.


You can store your San Marzano tomatoes at room temperature for up to a week or in the refrigerator for up to two weeks. Storing tomatoes in the fridge can make them less tasty and not as good. It’s best to use them quickly.

You can also preserve your tomatoes for longer by canning, drying, or freezing them. Here are some methods to do so:

  • Canning: Canning is a process of heating and sealing the tomatoes in glass jars to kill any bacteria and prevent spoilage. You can make your tomatoes whole, diced, crushed, or as a sauce. You will need a pressure or water bath canner, jars, lids, bands, and a canning kit.

Add lemon juice or citric acid to your tomatoes to make them more acidic and prevent botulism. Follow the instructions on the canning recipe and the canner manual for the best results. You can store your canned tomatoes in a cool, dark place for up to a year.

  • Drying: Drying is a process of removing the moisture from the tomatoes to extend their shelf life. You can dry your tomatoes in an oven, a dehydrator, or sun. You will need to slice your tomatoes thinly and evenly and arrange them on a baking sheet, a dehydrator tray, or a drying rack. You can also season your tomatoes with salt, herbs, or spices for extra flavor.

Follow the instructions on the drying method and check the tomatoes regularly for doneness. You can store your dried tomatoes in an airtight container in a cool and dark place for up to 6 months.

  • Freezing: Freezing is a process of storing the tomatoes in a freezer to preserve their quality. You can freeze your tomatoes whole, diced, crushed, or as a sauce. You will need to wash and dry your tomatoes and remove the stems and cores.
    • You can also peel and seed your tomatoes if you prefer. You will need to pack your tomatoes in freezer bags or containers, leaving some headspace for expansion.
    • You can also label and date your packages for easy identification. You can store your frozen tomatoes in the freezer for up to a year.


You can use your San Marzano tomatoes in various ways, from fresh eating to cooking to canning. Here are some ideas to inspire you:

  • Fresh eating: You can enjoy your San Marzano tomatoes fresh, as they are, or with some salt, pepper, olive oil, and basil. You can also slice them and add them to salads, sandwiches, or bruschetta. You can also make a simple tomato sauce by cooking it with garlic, onion, and herbs and serve it over pasta, pizza, or bread.
  • Cooking: You can cook your San Marzano tomatoes in soups, stews, casseroles, or curries. You can also roast them in the oven with some garlic, herbs, and cheese and serve them as a side dish or a dip. You can also make a tomato jam by simmering it with sugar, vinegar, and spices and spread it on toast, crackers, or cheese.
  • Canning: You can use your San Marzano tomatoes later in the year when fresh tomatoes are unavailable. You can make them whole, diced, crushed, or as a sauce, and use them in any recipe for canned tomatoes. You can also make your own salsa, ketchup, or chutney by adding some peppers, onions, vinegar, and spices to your canned tomatoes.


Growing San Marzano tomatoes in your backyard is a rewarding and enjoyable experience. You can grow your own organic and delicious tomatoes that are perfect for making authentic Italian dishes. You can also save money and reduce your environmental impact by avoiding store-bought tomatoes.

All you need is some seeds or seedlings, a sunny spot, and some basic care and maintenance. Follow our guide and tips, and you will have a sweet success with your San Marzano tomatoes. Happy gardening!


I am Gaushoul Agam

๐‚๐จ-๐…๐จ๐ฎ๐ง๐๐ž๐ซ & ๐‚๐„๐Ž

I am an experienced Horticulture Officer in the Department of Agricultural Extension in Bangladesh. I am committed to improving agriculture and farming.

I created ToAgriculture to address global food safety concerns. These concerns are caused by a growing population, diminishing farmland, and the impact of climate change on agriculture. I assist readers in learning modern farming techniques.

I also help them control pests and diseases. Additionally, I guide managing agriculture sustainably. All of this is aimed at creating a better and more successful future in farming.

I have experience in field crops and horticulture crops. I know about fruit and vegetable farming, managing pests and diseases, irrigation, and grafting. Come with me as I share my knowledge and experiences to help you create a better future.