Tomatoes are a garden staple, but they don’t always grow as perfectly as we’d like. The biggest, juiciest tomatoes are not only a matter of variety, though this certainly plays a role. Sunlight, moisture, fertility, and pruning are what ultimately make the best ‘Beefsteak’ tomato seeds reach their greatest glory.
If you want to grow giant tomatoes this season, use these 5 time-tested tips to nurture vigorous vines and outrageously huge fruits.
5 Tomato Growing Tips for Giant Fruits
Growing really big tomatoes is simpler than you think. Contrary to popular belief, it’s not about dumping on the quick-release nitrogen fertilizer. The variety selection also plays only a minor role in the big picture. Even if you plant the largest beefsteak seeds possible, they won’t yield huge fruits if they don’t have enough sunlight, water, and fertility.
As an organic farmer, I helped grow thousands of pounds of tomatoes every summer. The largest, juiciest fruits were always prized at our farmer’s market stands, and we took great care to ensure that we could grow as many as possible in a small space.
Here are 5 expert tips for growing giant tomatoes, no matter how big your garden.
Choose the Right Varieties
Through traditional breeding, giant tomatoes boast flavorful heritage genetics.
Giant tomatoes begin with giant genetics. Fortunately, this has nothing to do with genetic modification (GMOs). Instead, it’s all about selection. Traditional plant breeding has been used for thousands of years to develop unique tomato varieties by crossing the pollen of one plant with the ovules of another.
Every tomato variety was bred for a specific role, just like certain dog breeds are bred to hunt or herd. Cherry tomatoes are bred for sweet fresh snacking, and sauce tomatoes are selected for low moisture content, ideal for canning. Large-fruited slicer varieties are bred for giant tomatoes with broad shoulders, meaty texture, and high yields. Most of these types fall under the categories of “beefsteaks” or “heirlooms.”
‘Beefsteak’ began as a single cultivar but has expanded to hundreds of different varieties with similar qualities. They are called beefsteaks because they are beefy, weighing up to two or three pounds each. The tomato texture is described as “meaty,” but don’t let this scare vegetarians. These juicy fruits are actually just dense, making them perfect for sandwiches, salads, and burgers.
Heirloom tomatoes are varieties that have been passed down for generations. They are open-pollinated (non-hybridized), which means that you can save their seeds and grow the same plants next year. The original ‘Beefsteak’ was an heirloom, and this categorization is commonly associated with those big, red, fragrant fruits with nostalgic, classic tomato flavor.
Technically, any tomato variety can be an heirloom (including cherries and sauce tomatoes), but the term heirloom is often used to describe big slicer tomatoes with wide shoulders, ribbed texture, and colorful interiors.
Our favorite cultivars to yield giant tomatoes include:
- ‘Beefsteak’ Pole Tomatoes: The iconic heirloom vine yielding one to two-pound fruits with rich, old-time flavor.
- ‘Cherokee Purple:’ Classic 10-12 ounce heirlooms on vigorous vines with balanced flavor.
- ‘Cherokee Carbon:’ Large purple-hued beefsteaks with fewer cracks and early yields.
- ‘Pineapple Pole:’ Large, beefsteak type with few seeds and complex, low-acid fruity flavor.
But choosing the right large-fruited variety is only the beginning. You have to nurture the plant and give it everything it needs to grow those giant fruits. Many people make the mistake of expecting big tomatoes to grow from thirsty, shaded, hungry plants.
Provide Consistent Moisture (Water Deeply!)
To thrive, tomatoes crave consistent, deep watering for robust growth.
On average, you should give your tomato plants about one inch of water per week. Depending on the soil conditions, humidity, temperature, and rainfall, this may mean irrigating one to three times weekly. Young plants need regular watering in the first weeks after transplanting. Mature plants need extra water in hot, dry, sunny weather, especially while fruiting. Container plants need more frequent irrigation because they dry out quicker.
It should come as no surprise that tomatoes are thirsty plants. The verdant foliage, vigorous vines, and abundant juicy fruits require lots of water. Many gardeners are disappointed by small fruits when they don’t water their tomatoes deeply. Shallow irrigation only saturates the upper few inches of soil. If the water doesn’t reach deeper into the root zone, the tomatoes fail to develop a strong root system and become more prone to drought stress later in the season.
Preventing Drought Stress
Plenty of care yields abundant fruitfulness.
Stress is not good for anyone, especially when you are trying to create something massive. Imagine your tomato plants like pregnant women: They need lots of water and nutrients to produce huge babies! Without sufficient water, tomatoes focus their energy primarily on survival. Reproduction (fruit production) goes to the wayside because the plant is just barely having its needs met.
While deep-rooted tomatoes can be very drought tolerant once mature, they still need plenty of moisture in the beginning. Dry-farmed tomatoes are grown without irrigation for enhanced flavor. However, this methodology requires extra-rich soil and proper preparation. Most gardeners are growing tomatoes in raised beds that need a generous soaking at least once or twice a week in peak summer.
Mulch is another key secret to happy tomatoes. Bare soil dries out much more quickly in the sun. A layer of dry straw or shredded leaves can make a huge difference in moisture conservation. The mulch keeps the soil damp, cool, and protected from UV rays. Moreover, mulch suppresses weed growth and enriches the soil over time.
Spread a two to three inch thick layer of mulch over tomato beds after planting. Leave a one to two inch ring of space around the base of your plants so the mulch doesn’t smother the stems. It’s also helpful to remove dropped fruit or leaves to prevent the spread of disease.
Maintaining Consistent Moisture
Consistent moisture ensures plump, crack-free tomatoes at harvest time.
Consistency is key when watering. You don’t want huge fluctuations between bone dry and sopping wet. Instead, aim for the soil to feel like a wrung-out sponge most of the time. If you dig your hand 6-12 inches deep in the bed, you should feel a loamy, moist soil texture. Dry, brittle soil can tremendously reduce the size and quality of your tomato fruits.
Inconsistent moisture also leads to blossom end rot and cracking in tomatoes. Who cares if you grow a huge tomato if it has a rotten “butt” and unsightly cracks? Big tomatoes are extra prone to cracking, so many gardeners advise watering them less. This rumor only holds true at the very end of the fruiting window, right before harvest.
You need to maintain consistent moisture throughout the growth cycle of the plant, and then you can cut back on water for one or two days right before picking a vine-ripened fruit. However, if you are watering deeply in well-drained soil, cracking isn’t usually an issue because the water flows freely through the soil profile. The roots should never sit in soggy soil.
Best Soil Type and Irrigation for Tomatoes
Nourish your tomatoes with well-draining soil and smart irrigation.
Tomatoes thrive in loamy, compost-rich soil. They can grow in poor soils, but they may not yield the big, flavorful fruits you crave. Raised beds and large grow bags are ideal for cultivating these deep-rooted plants.
Drainage is very important because the roots need to breathe and drink at the same time. When irrigating, the water should never puddle up on the surface. It should infiltrate down into the profile fairly quickly, leaving a nice, moist soil surface.
Overhead irrigation with sprinklers is not recommended because the moisture sitting on the leaves makes them more prone to foliar diseases. Moreover, a lot of water is wasted because it never reaches the soil surface, which can lead to more problems with drought stress.
Irrigating with drip lines or soaker hoses is ideal. An olla (clay pot irrigation) is also highly beneficial for gardeners who tend to overwater. The olla works by gradually wicking moisture into the surrounding soil only as the plant needs it. If the soil is very wet, the olla won’t release any more moisture until it dries out again.
Plant in Full Sun
Maximize your tomato harvest with full, uninterrupted sunlight exposure.
Shade-grown tomatoes will rarely (almost never) yield big tomatoes. This is because tomatoes evolved to grow in open, bright, sunny areas. The wild nightshade ancestors of these plants originated in South America as a low-growing weed that thrived in hot, sunny weather. Tomatoes demand at least six to eight hours of direct sunlight every day to produce large fruits.
Since they are often the stars of the summer garden, I always keep tomato plants in my best south-facing raised beds. You want to be sure there are no structures, fences, shrubs, or trees that cast shadows over the plants. This is easier to accomplish with vines because you can trellis them upwards. Lower-growing bush (determinate) varieties need to be placed on the southernmost side to ensure they don’t get shaded.
If you are growing corn, trellised cucumbers, or other tall crops nearby, plant them to the north of your tomatoes so they don’t cast afternoon shadows. Even in the hottest climates, most tomatoes prefer full sun to ensure prolific yields.
Signs of Insufficient Light
Pale leaves signal insufficient chlorophyll.
If a plant is receiving too much shade, its foliage may look pale green or yellow. The growth will be slow and stunted because there isn’t enough sunlight to fuel efficient photosynthesis. Photosynthesis is the process plants use to convert sunlight, water, and carbon dioxide into sugars. Those sugars are used to grow our favorite big tomato fruits.
Photosynthesis occurs in chloroplasts, which are special cells in the leaves that absorb light. Chloroplasts have a green pigment called chlorophyll that gives tomato plants their green color. If the plants are lacking in green color, it’s a sign that there isn’t enough chlorophyll. This is typically due to insufficient sunlight.
The structure of these plants also explains why they need lots of sunshine. Notice how shade perennials like hostas or coral bells have large, broad leaves. Shade plants are adapted to receive trickles of light through a forest canopy. In contrast, tomato leaves are long and pinnately compound. Their leaf surface has evolved to soak up rays in bright, unshaded conditions.
Insufficient light is also very obvious when tomatoes begin flowering. Shaded plants may not grow distinct yellow flowers. No flowers means no fruit. Once you’ve ruled out issues with pollination, water, or fertility, shade is probably the reason for flower-less tomato plants. You can transplant to a brighter location like a south-facing raised bed or a large portable grow back.
If the plant was growing in intense shade, give it some time to gradually adjust to sunnier conditions so it doesn’t get sun-scorched by the shock.
Use Balanced Fertilizer (Less Nitrogen!)
Balance nitrogen for robust tomato growth without sacrificing fruit size.
It may seem counterintuitive to cut back on nitrogen when growing a heavy feeder crop like tomatoes. However, high-nitrogen fertilizer can often be a key cause of small fruits. Excessive amounts of nitrogen promote an overgrowth of foliage, pulling energy away from flower and fruit production. Nitrogen is a vital nutrient for plant growth, but there can be too much of a good thing.
Dumping on the nitrates leads to outrageously bushy, deep green-hued plants. Over-fertilized tomatoes often lack flowers and fruit. It is much more important to provide balanced fertility. A balanced fertilizer has nutrient ratios that are close together. For example, in Espoma Tomato Tone fertilizer, the NPK ratio is 3-4-6. This means that it is only 3% nitrogen, and higher in phosphorus and potassium.
These nutrients come from organic sources like feather meal, poultry manure, greensand, and potash. This is ideal for tomatoes because the fertilizer will slowly release into the soil throughout the season. You can apply once at planting and optionally side-dress once the plants start fruiting. Tomatoes use more nitrogen in their early leaf growth stages and more potassium and phosphorus during the fruiting phase.
In general, nitrogen is most needed for foliar and root growth. Phosphorus stimulates flower and fruit production. Potassium regulates photosynthesis and helps fruits ripen properly. Plants need more potassium than other nutrients to grow big, juicy tomatoes. Fortunately, potassium is abundant in greensand, hardwood ashes, and kelp meal. Compost usually provides sufficient phosphorus, and composted manure can provide plenty of nitrogen.
Slow-Release vs. Synthetic Fertilizers
Opt for gentle, slow-release organic fertilizers for healthy tomato growth.
It’s best to use slow-release organic fertilizers because they reduce the risk of overfertilization or nitrogen toxicity. Quick-release synthetic nutrients provide an instant megadose of fertilizer to the plant, sometimes shocking it or even killing it (if you over-apply the product). Excessive amounts of synthetic fertilizer can degrade the soil and “lock up” other micronutrients, making it difficult for tomatoes to get everything they need to thrive.
In contrast, balanced organic fertilizers are gentle and natural. Soil microorganisms gradually break down the nutrients to make them available to the plants as they are needed.
Prune Off Suckers
Prune tomato suckers for bigger, cleaner, and healthier plants.
Most of us think of pruning as a staple for perennial and herbaceous crops. However, pruning is also an important tip for growing really big tomatoes. Most tomato plants produce prolific amounts of suckers. Suckers are the elongated shoots that grow from the “elbow ditches” where a vine intersects with the main stalk. If left in place, each sucker can grow out into an entirely new vine. More vines may seem like a good thing, but they can actually detract from fruit growth.
Suckers are relatively harmless to tomato plants, but they still “suck” away energy from fruiting. As a high-production organic farmer, we always remove the suckers from our tomato plants as often as possible. This communicates to the plant, “Hey, please focus on growing tomatoes rather than more stems and leaves!”
Another benefit of removing suckers is cleaner plants that are easier to trellis. A tangle of vines can quickly become messy, unsightly, and prone to diseases. Removing suckers ensures that just one or two vines stay on the trellis, channeling all of their energy into growing flowers and fruit. This will ensure lots of airflow through your tomato patch to reduce the risk of diseases like blight or powdery mildew.
How to Remove Suckers
Easily maintain tomato plants by promptly pruning away suckers.
Pruning away suckers is very quick and easy. If you catch them while they’re small, you can ensure that each vine stays in its own lane. Overgrown tomatoes are much more difficult to tend and harvest, so I like to start removing suckers as soon as they appear.
First, locate the “elbow ditches” or V-shapes where leaf stems intersect with the main stalk. A sucker will sprout outwards with a cluster of new leaves at the top. They almost always grow at a 45° angle from the main vine.
On young plants, it is important to use sanitized pruners or scissors to cut off the larger suckers. You don’t want to risk snapping a sucker and accidentally uprooting the new seedling. Instead, chop off each sucker as you find it. If the suckers are still an inch or so long, pinching will suffice.
As plants mature, it’s best to take five minutes once or twice a week to snap off any suckers you see. This process becomes quite fun for children if they are taught correctly. As you remove suckers, you can also train the vines up the trellis and check for ripe fruit. If a sucker gets too big, cutting will be necessary. You don’t want to tear or rip the flesh of the plant. A clean cut is important to ensure proper wound healing so the plant does not succumb to disease.
While removing suckers isn’t 100% necessary, it is a helpful step for growing lots of big, juicy fruits. Rest assured, if you forget to remove suckers, your plants will still yield a nice harvest. Pruning is simply a bonus step for plant vigor and productivity.
Final Thoughts
If you want to grow really big tomatoes, don’t skimp on sunlight, water, balanced fertility, and pruning. Choose a large-fruited beefsteak or heirloom variety with the proper genetics to yield the color, flavor, and size you desire. Provide six to eight hours of direct sunlight, consistent moisture, well-drained soil, and a balanced organic fertilizer high in potassium.
Avoid high-nitrogen synthetic fertilizers. Remove the suckers as often as possible to train the plant to focus its energy on growing flowers and fruit!
