Growing Tomatoes: How To Plant, Maintain, And Harvest

Classifications Of Tomato Plant Varieties

To begin narrowing down your options for tomato varieties to grow, you’ll need to decide whether they should be determinate or indeterminate. Both have the same tomato growth stages, still they vary in duration.

Determinate, or bush, varieties typically grow to a height of 2 to 3 feet (60 to 90 cm). In general, these varieties produce a glut of ripe fruits all at once. Their fruiting cycle and post-fruiting leaf development stage are relatively short. The beginning of the growing season is when they produce the most. When growing determinate tomatoes, don’t cage or stake them.

Indeterminate, or vining, varieties yield mid-season and late-season large, slicing fruits from early July until frost. They maintain a steady fruit production rate because their leaves continue to expand throughout the growing season, which makes indeterminate varieties perfect for tomato growing on a commercial scale. Indeterminate plants require staking to grow properly.

Tomatoes’ days to harvest are the foundation for another classification of the crop varieties. Here is a breakdown of these three groups.

When deciding which types of tomatoes to grow, it’s critical to consider the compatibility of the field’s growing conditions with the needs of the variety.

Growing Conditions For Tomatoes

Farmers need to locate optimal growing conditions that meet all the tomato plant requirements. Make sure that growing plants have access to plenty of sunshine, consistent warmth, sufficient watering, and rich soil.

Sunlight And Temperature

Tomatoes are warm- and sun-loving plants. Full sun for at least 8 hours a day is essential for growing healthy crops. They also need a warm environment; tomato growing temperatures between 71 and 84˚F (22 and 29˚C) will be ideal. Though the crops can endure cool weather, their development will be stunted. At the same time, frost might become a problem for unprotected tomato plants, making them perish.

Growing world-class crops is only possible in an environment where the low and high temperatures are somewhat consistent. Low-quality fruit or fewer harvests are common outcomes of growing in climates with large temperature swings.

Humidity

The ideal relative humidity for growing tomatoes is somewhere between 65 and 85%. Increased humidity is linked to the spread of foliar diseases and a growing rate of blotchy (uneven) ripening. Higher humidity also inhibits pollen release and distribution, whereas lower humidity causes pollen drying, which can result in undersized, misshapen, or hollow fruit.

Water

Tomato plant water requirements are 1 to 2 inches (2.5 to 5mm) of moisture every week to grow and produce well. Variables such as temperature and plant density influence the rate of evapotranspiration and, thus, the crop water needs.

Plants growing in sandy soil fields might need more watering than those in clay soil fields because the former drain more quickly. However, the plant’s root system is extensive, reaching depths of up to 5 feet (1.5 m) in deep soils. As tomatoes grow, their root systems expand, allowing them to draw water from further down in the soil and making them less susceptible to drought.

Soil

Field-grown tomatoes thrive in nearly every type of soil (with the exception of heavy clay). Similar to other vegetables, they grow best in sandy loam soil that drains well and has a pH of 6.2 to 6.8. The soil for growing tomatoes should be high in phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg). The bare minimum for soil temperature is 57°F (14 °C); the optimum is between 65 and 70°F (18 and 21°C).

When And How To Plant Tomatoes

In most countries, seedlings for commercial tomato growing are planted in the middle to late stages of spring. Tomato planting can begin earlier in the year in regions with warmer-than-average temperatures. On the other hand, growers in the north typically transplant their seedlings in early summer. Before planting, farmers need to do several operations, including soil and seedling preparation.

Preparing The Soil

You should start soil preparation for growing tomatoes a couple of weeks before you plan to transplant seedlings. By plowing to a depth of 23.6 inches (60 cm) after removing weeds and crop residue, farmers improve drainage and soil aeration.

A week later, farmers commonly apply pre-planting fertilization, like aged manure or synthetic fertilizer. Although it would be more economical to spread the top dressing across the rows, application across the entire field might have a more positive effect on tomato plant growth. Right before planting, till the soil to a depth of 12 to 18 inches (30 to 45 cm) to encourage a more robust root system.

One more step before you can plant tomatoes is soil solarization, which is especially important in growing regions with cold soil during the planting season. This method helps keep the root zone at an ideal temperature of around 70°F (21°C) and prevents weeds from growing. When it comes to covering their rows, some farmers prefer green or black infrared-transmitting (IRT) polyethylene, while others use standard 1–1.25 mil black plastic.

Preparing The Seedlings

Farmers can get a head start by purchasing and planting pre-grown tomato transplants. However, if you want to grow your plants from seeds, which gives you more control over the transplanted material, there are a few things to keep in mind.

A high-quality transplant takes about 5–7 weeks to grow. Maintaining nighttime temperatures over 60°F (15°C) encourages fast development. The average height of the transplants is 8 inches (20 cm), and they each have about 3–5 true leaves. Remember that seedlings aren’t ready for transplanting until they grow a few true leaves.

Typically, “hardening” (i.e., artificially stressing) seedlings is necessary to get them fit for transplanting. This process, which may involve moving the seedlings outside for a regulated duration or other techniques, is intended to help the tomato acclimate to an outdoor growing environment. To simulate water stress, most farmers progressively cut off their crops’ watering. Usually, they’ll switch off the water supply 13–15 hours before the transplanting procedure begins and then turn it back on when it’s finished.

Planting Tomatoes

Once all the necessary preliminary operations are completed, it is time to plant tomatoes. The farm workers either make marks on the plastic film or in the ground to indicate where the seedlings will go. After that, they prepare holes and set the seedlings inside.

The tomato planting distance should be 18 to 24 inches (45 to 61 cm) between plants and 48 to 72 inches (122 to 183 cm) between rows. Indeterminate plants tend to grow larger, so be sure to give them more room. There won’t be as much of a chance of disease spreading if tomato spacing allows each plant to grow in the light and air.

How To Care For Tomatoes

Tomatoes are a delicate crop, and the harvest depends on the farmer’s care throughout the growing season. Making sure plants have enough water, enriching the soil, and combating diseases and pests are all crucial steps in successful tomato plant growing.

Watering

Prudent irrigation is essential for healthy development and high harvests when growing tomatoes on a large scale. If you don’t give your crops enough water, their leaves will curl upward and turn yellow. This is typical in the middle of summer when heat and a lack of rainfall cause heat stress on plants.

Remember these two principles for effective tomato plant watering:

• Focus irrigation on the plant’s base. Be careful not to moisten leaves and stems. Wet leaves are an ideal breeding ground for the bacteria and fungi that cause fruit rot. Supplying water to the plant’s root zone will help avoid this issue. Rely on drip irrigation, where water is not wasted by running off the plants and instead seeps slowly into the soil.
• Soak the soil deeply — to at least 10 inches (25 cm). If you water the soil deeper, the plant’s roots will also grow deeper. Thus, plants can establish themselves better and grow more robust even in the event of drought.

Tomato farmers can benefit from using the Soil moisture feature in EOSDA Crop Monitoring since it allows them to routinely track the moisture dynamics in both the root and surface zones and water the crops at just the proper rate. Information on soil moisture, along with accurate weather forecasts will help you predict the moisture levels in your fields and determine how often to water your tomato plants for the best results.

Weed Management

Weeds pose a significant threat to newly transplanted plants during their first month of growing in the field. Growing robust tomato crops calls for a multifaceted approach — integrated weed management — that includes proper crop rotation, cultivation, sanitation, watering, and herbicide application. The latter requires extra caution because herbicide exposure can permanently distort plant leaves. So take care not to accidentally spray herbicides on crops.

Fertilizing

Tomato plant nutrient requirements are quite broad. To grow vigorously, crops need the macronutrients nitrogen (N), phosphorus (P), and potassium (K) and the micronutrients zinc (Zn), copper (Cu), iron (Fe), and sulfur (S). Nitrogen deficiency may be to blame if the plants are growing slower, while phosphorus deficiency may show up as a bluish-green hue on the leaves and poor plant development. However, excess macronutrients (especially N) can cause fertilizer burn, which shows up as yellowing or browning of the plant’s leaves.

Even before planting tomatoes, farmers can use EOSDA Crop Monitoring’s Zoning tool to assess field productivity. For this, we rely on an algorithm that sorts areas according to their typical NDVI values obtained from previous years’ satellite images. A low NDVI suggests low-productivity zones, which might need extra fertilizer for growing optimal tomato crops, while a high NDVI is associated with high-productivity zones.

Locating low-productivity zones in your field will save you money in two ways:

• Soil testing. Instead of taking soil samples from the entire field, focus on low-productivity areas.
• Precise fertilizing. Before planting crops and periodically while they are growing, amend the soil with the lacking nutrients only where needed, and thus optimize yields.

Mulching

To keep the soil moist enough for growing plants, spread a 2-inch (5-cm) layer of organic mulch over the plant root zone. Viable options for growing tomatoes are mulch comprised of either shredded bark or grass clippings. By acting as an insulator, mulch will keep soil temperatures from fluctuating excessively. Mulch also prevents water loss through evaporation and helps suppress weeds.

Pruning

If you want your plants to put all of their resources into growing fruit instead of leaves, you should prune them. Larger fruit, improved airflow, and less disease susceptibility are all benefits of removing suckers, low-hanging branches, and wilted leaves.

The ideal time to start pruning in your tomato plantation is just as you notice the flowers opening. June or July is a common time frame for this. Continue the light pruning one-to-two times every two weeks until the end of the growing season to avoid stressing the plants by removing too much foliage at once. The following guidelines will teach you how to prune a tomato plant:

• Find the suckers growing in the “V” formed by the plant’s branches and stem.
• Carefully trim the suckers with clean pruners and disinfect them before moving on to the next plant to prevent disease proliferation.
• Remove (stake) any low-hanging branches, since they can easily get infected and spread the disease throughout the plant.

Pest And Disease Management

The prevalence of tomato plant diseases is a major barrier to increasing the productivity of commercial growing. More than two hundred different pathogenic fungi, bacteria, viruses, and nematodes can infect growing plants. Under favorable conditions, these diseases quickly spread from one plant to another.

Among the most severe crop diseases are wilts and blights (Fusarium wilt, southern blight, gray mold), foliar diseases (early blight, Septoria leaf spot, gray leaf spot, late blight), fruit rots (anthracnose), and soil rots (buckeye rot, Pythium rot, Rhizoctonia soil rot). Late blight is especially pernicious since it can cause an economic loss of 20–70% ^{Nowicki, M. et al. (2013, October 11). Late Blight of Tomato. In: Translational Genomics for Crop Breeding: Biotic Stress, Volume 1. Varshney, R. K., Tuberosa, R. (Eds.). Wiley, Hoboken. https://doi.org/10.1002/9781118728475.ch13.}.

Fortunately, farmers can now combat these threats with technological tools. The Disease risk feature in EOSDA Crop Monitoring leaps forward in disease prevention and management. By combining plant growth stage data with hyper-local weather forecasts, our algorithm calculates disease risk probabilities for up to two weeks ahead. Growers who know which fields are at which risk can optimize their use of chemical treatments for more agricultural resilience and sustainability.

Pests such as hornworms, flea beetles, cabbage loopers, aphids, and cutworms can cause serious damage in the early stages of tomato growth. Stink bugs and tomato fruitworms are only two examples of the many insects that can feed on the fruit later in the growing season. The fruitworm is one of the most economically significant tomato plant pests due to its high damage potential and extensive host range. Growing onions and other natural pest repellents as companion plants for tomatoes might be part of your sustainable pest management strategy.

To check for tomato plant disease and pest infestations in your fields, use the Scouting feature in EOSDA Crop Monitoring. Managers can employ this feature to dispatch scouts to different parts of a field based on the condition and density of vegetation there and then promptly receive in-site photos and reports. And scouts, especially in remote, no-service locations, will appreciate the convenience of the Scouting app’s offline mode.

With the new Disease risk feature in EOSDA Crop Monitoring, you can achieve even more in terms of crop health and yields. It will help you spot potential health problems with your crops early on so that you have enough time to take preventative measures. To learn more, get in touch with our sales team at sales@eosda.com.

How Long Does It Take For Tomatoes To Grow?

The tomato’s growing time depends on the variety. Small determinate varieties ripen faster than their larger counterparts, such as beefsteak and many heirloom varieties. The typical time to harvest tomatoes is between 60 and 100 days after transplanting seedlings and 100 and 120 days after planting the seeds. Some early cultivars, though, can be picked in as little as 50 days after being transplanted.

When And How To Harvest Tomatoes

The optimal tomato harvest time varies by growing region. The earliest fruits ripen in late spring and persist through the summer in regions with unusual growing climates, like areas of California and the Pacific Northwest. Late spring to early summer is the ideal season for harvesting fruit in the Mid-Atlantic. Fruits in the Northeast and Midwest growing regions begin ripening in July and keep up until the first fall frost. Meanwhile, heatwaves typically put a stop to the tomato harvest time in the South and Southwest at the beginning of June.

Choose the method of harvesting tomatoes based on the fruits’ final use. For instance, traditional manual harvesting is a better option for direct consumption or producing whole canned tomatoes, whereas mechanical harvesting is acceptable for producing sauces and concentrates. Self-propelled machines specifically designed to clear-cut plants and sort harvested fruits from plant residues are used in mechanized harvesting.

If you strive for high yields, keep in mind that commercial tomato growing relies on extensive planning and pinpoint execution. You can assure the profitability and sustainability of your farming business by growing the right varieties, preserving soil health and fertility, implementing pest and disease control measures, and adopting best practices across the whole production cycle.