Ultimate Tomato FAQ: 40 QUICK Answers to Garden Tomato Problems

Tomatoes are the most popular garden crops, but they can, unfortunately, face many problems. Diagnosing issues sometimes requires endless internet searches, and they don’t always provide quick answers. 

This article brings all the most common tomato problems and answers into a single location so you can rapidly diagnose and fix your crop! It includes everything we wish we knew before we started growing tomatoes.

40 Common Tomato Problems and Answers

There is no need to panic when your plants and fruits don’t look how you expected them to. These nightshade-family crops are extremely resilient, and most issues can be fixed with simple modifications to the growing environment. 

Why Are Tomatoes Cracking?

Cracked tomatoes usually come from overwatering right before harvest or waiting too long to harvest. Large beefsteak and heirloom types are the most prone to cracking. It’s better to harvest larger fruits slightly before they are fully ripened, and store them with their “shoulders” (tops) facing downward so the tender undersides don’t burst.

Why Aren’t My Tomato Plants Flowering?

A lack of flowers is linked to growth stage, sunlight, fertility, or disease. First, check that your plant is growing in full sunlight with 6-8 hours of direct light per day. This crop is easy to transplant and may start blooming once it has enough light.

Nightshade-family crops go through two phases of growth: vegetative (leafy) growth and reproductive (flower and fruiting) growth. If your plants aren’t producing flowers, it may be too early in the season or the plants may be too young. It could also be too hot.

Alternatively, they may be overfertilized with nitrogen and channeling all their energy into growing more leaves and stems. To fix this, flush the soil with water and remove any excess fertilizer that you can visibly see. Use a woody, carbon-rich mulch like straw or wood chips to help balance out excess nitrogen.

Once you’ve ruled out these issues, begin looking for signs of disease. Bacterial wilt and some blights can cause a lack of flowers.

Why Are My Plants Wilting?

Underwatering (drought), overwatering (root rot), or bacterial wilt are common reasons for wilting. First, check the foliage. Is the entire dehydrated and limp, with dry soil at the base? This is a sign of underwatering. Add moisture and mulch.

If the foliage feels slimy or droopy, and the soil is very wet, the issue is likely overwatering. Coincidentally, too much water can cause the roots to suffocate, which makes it difficult to uptake moisture. This causes wilting. Cut back on irrigation and improve soil drainage with compost or broadforking.

If only the top leaves are wilting, and there is plenty of water, you may have bacterial wilt. Milky substances will flow from a cut stem and the inside of the stems will appear decayed. You may have to pull the plant to prevent spread, as there is no cure.

What Are The Black Spots On My Tomatoes?

Black spots on the leaves are typically a sign of Septoria leaf spot, late blight, or bacterial canker. If the fruits have black rotten spots on the bottom, it is probably blossom end rot. But when the black areas are speckled around leaves and fruits, it is likely bacterial speck disease.

How Do I Fix Blossom End Rot?

The quickest way to fix blossom end rot is to avoid watering extremes. While calcium deficiency is technically the root cause of this physiological issue, most soils actually have plenty of calcium. The real problem is that the calcium becomes unavailable when there is too little or too much moisture. 

First, remove fruits with blossom end rot and compost them. This is not a disease, so you don’t have to worry about it spreading. Next, check the bed moisture and aim for consistent watering over the next few weeks. Use mulch to conserve moisture and avoid large fluctuations from wet to dry. Future fruits should develop without rotten “butts.” 

What Are The Green Caterpillars On My Plants?

Tobacco or tomato hornworms are the most common caterpillar pests of the nightshade family. They can devour large amounts of foliage in a short period of time. Their bodies are camouflaged with the vines, with white diagonal stripes and distinct reddish “horns.” Hand-plucking them is the best way to get rid of them. Relocate them to wild nightshades, drown them in soapy water, or cut them in half. 

How Do I Get Rid of Tomato Hornworms?

Hand-plucking is the best method to get rid of these nasty pests. For prevention, plant insectary strips to attract parasitic wasps that parasitize the hornworms. You can also use row fabric to cover plants at night. This works because the adult form of the hornworm is actually a five-spotted hawk moth. The moths lay their eggs on the undersides of leaves at night. Bt sprays can also be helpful for killing the caterpillars without harming other insects.

How Do I Control Aphids On Tomato Plants?

The best way to get rid of aphids is to spray a strong blast of water on the leaves. Do this in the morning so that the foliage has time to dry out, which reduces the risk of fungal diseases. If this does not work, a neem oil or horticultural oil spray will kill the aphids. You can also companion plant with beneficial species like French marigolds, white alyssum, or nasturtiums to attract aphid predators like ladybugs, hoverflies, and lacewings.

What’s The Best Way To Treat Powdery Mildew?

Powdery mildew looks like white flour dusting over your plant leaves. Diluted neem oil, hydrogen peroxide, baking soda, or copper treatments are common DIY remedies. But first, it’s best to practice prevention. Carefully prune off infected leaves and sanitize tools with a diluted bleach solution. Throw infected foliage away to prevent proliferation of spores in your compost pile. 

Next, apply your spray of choice to the affected areas. Do not mix-and-match these treatments, and wait at least one or two weeks between applications. Use pruning to ensure more airflow and avoid overhead watering because moisture on the leaf surfaces can cause more mildew to grow.

How Do I Prevent and Treat Late Blight in My Garden?

Late-summer infections of late blight are a common issue in nightshade-family crops. You may notice brown spots or lesions with shriveled-up, dry leaves. On the undersides, there are usually white fuzzy spots. It is essential to prune away infected plant debris (ideally on a hot sunny day) and throw it in the trash or burn them. Sanitize your tools and do not compost the infected leaves. 

Unfortunately, management is the only issue. To prevent further infection, regularly prune and improve the airflow between plants. Use drip irrigation to avoid splashing moisture on the foliage. Consider growing in a greenhouse to protect plants from wind and rainfall. 

Why Are the Leaves Turning Yellow?

Yellowing tomato leaves can be a sign of nutrient deficiency, transplant shock, overwatering, underwatering, or disease. A lack of nitrogen fertility is the most common cause. Young plants also may be struggling to adapt after transplanting.

Ensure loose, compost-rich soil and protection from temperature extremes. Maintain moderate moisture levels, ensuring that you don’t oversaturate or drought-stress the plants. Check this guide for common diseases that cause yellow leaves.

What’s the Difference Between “Heirloom” and “Hybrid” Tomatoes?

Heirloom varieties have been passed down through generations for at least 50+ years, and have stable genetics. This means you can save seeds from them and they produce the same plant each season. The seeds are “open pollinated,” and can easily pollinate themselves or cross with other OP tomatoes to produce new varieties.

Hybrid varieties are crosses between two parental lines. Contrary to misinformation, hybrids are NOT genetically modified. They are produced by plant breeders in gardens by taking the pollen from one inter-crossed parent line and bringing it to the flowers of another plant. This creates extra vigorous new plants called F1 hybrids. But if you save the seeds from these types, they will not regrow “true to type” because they have a lot of genetic diversity. Hybrid varieties tend to have better disease resistance, but are not ideal for seed savers.

What’s the Difference Between “Indeterminate” and “Determinate”?

Indeterminate varieties are vining types that require trellising support. Their growth is “not determined,” which means they can hypothetically continue growing and fruiting until it gets too cold. Their fruit grows continuously throughout the season.

In contrast, determinate varieties are bush types that do better with a simple tomato cage or stake. Their growth is “pre-determined,” which means that, once they reach a certain size, they stop growing. These types produce all their fruits in one or two big flushes, then they die.

When Should I Harvest My Tomatoes?

The best time to harvest fruits is in the “breaker stage” when they have started blushing to 40-60% color-changed ripeness. Picking slightly early still ensures vine-ripened tomatoes, but it prevents issues like cracking, pest damage, and overripening, which can occur if left in the garden for too long. Finish ripening fruits on the countertop for ideal flavor and texture.

Why Are My Seedlings Dying?

Damping off disease is the most common attacker of nightshade seedlings. If there is a lack of airflow, overcrowding, poor drainage in the potting soil, or excessive humidity, the fungus may attack the base of the seedlings, causing them to collapse and die. To prevent this, plant in a well-drained potting mix and then newly germinated seedlings to one plant per cell. Use a fan in your nursery or propagation area, and water from the bottom to prevent excess moisture.

Why Are My Tomatoes Growing Leggy?

Leggy or spindly growth is a sure sign of low sunlight. These plants need at least 6-8 hours of direct light per day. Lots of sunshine is crucial for proper growth, but plants in the shade tend to lengthen their stems in an attempt to reach toward the light. The solution is to transplant to a brighter area, and prune away the tip to promote bushing.

What Are The Signs Of Overwatering?

Yellowing leaves, droopy foliage, and smelly or rotten roots are the most obvious signs of overwatering. Plants may appear wilted, but the soil remains saturated. If there is too much moisture in the root zone, the roots can suffocate and succumb to fungal pathogens. This makes it difficult for them to uptake water, causing the rest of the crop to droop.

How Can I Fix Root Rot?

Improve soil drainage with compost, mulch, and aeration via broadforking. Cut back on irrigation to help the plants dry out before drinking again. In extreme cases, you may need to uproot the plant and prune away rotten root areas before replanting. 

How Do I Fix Excessive Leaf Growth?

Too much nitrogen is the most common cause of excessive foliage. Pruning is the first step to improving airflow and reducing leafy growth. Next, amend with phosphorus-rich fertility like compost or bone meal to support the shift toward reproductive (fruit and flower) growth. Carbon-rich amendments like mulch and straw can help “lock up” excess nitrogen.

Why Are My Plants Producing Tons Of Leaves With No Fruits?

Overfertilizing with nitrogen causes lots of leaves without fruits. Avoid quick-release synthetic fertilizers that are high in nitrogen. Instead, choose slow-release organic fertilizer blends. Look for balanced ratios with N-P-K numbers that are close together, such as 3-4-6 in Espoma Organic Tomato-tone. Prune away excess leafy growth and flush the ground with water.

Do Tomatoes Need Bee Pollination?

These nightshade crops can be pollinated by bees or wind, but they don’t technically need them. The flowers are considered “perfect,” which means they have both male and female parts inside a single bloom. However, the pollen still needs to be transferred from the stamen (male part) to the stigma (female part) to properly fertilize the flower and begin growth into a fruit. If bees are not present, you can hand-pollinate by gently shaking your plants or vibrating an electric toothbrush on the outside base of each flower.

Do I Have To Prune Tomatoes?

Pruning is not required, but it is recommended. When you remove lateral branches, it signals to the plant to put more energy toward flower and fruit production. It also makes it easier to trellis and train the plants, ensuring airflow, access, and aesthetics. Always use sharp, sanitize pruners to cut away suckers (side shoots) and overgrowths of leaves near the base. Ideally, train your plant to one or two “leader vines” where it can funnel the bulk of its resources.

How Can I Fix Air Circulation In My Garden Patch?

Pruning and spacing are key for air circulation. Most varieties should be spaced a minimum of 18-24” apart. Use sharp, sanitize pruners to regularly remove suckers and side-vines. If you don’t want to prune, space plants farther apart and use tomato cages to keep them contained. Air flow is crucial for preventing disease and ensuring plenty of light exposure for all of the leaves.

Why Are My Tomato Plants Dropping Their Flowers?

Dropped flowers are a sign of stress. Cold weather, extreme heat, inconsistent moisture, nutrient deficiencies, and diseases can be the cause. These plants need temperatures between 55°F and 90°F (13-32°C) to properly flower and fruit. You can moderate temperature stress with shade cloth, row cover, and seasonal planting variations. It’s also vital to ensure a balance of water (not too much, not too little) and balanced fertilizer (avoid overdoing the nitrogen). Bacterial wilt and some blights can also cause flower drop.

What Are The Signs and Solutions For Tobacco Mosaic Virus?

Mosaic virus attacks any nightshade crops and causes very obvious patchy “mosaic” leaf discoloration. The mottling looks like yellow or dark green coloration, eventually leading to distorted leaves and weird brown streaks on the flowers. 

While this virus is incurable, it doesn’t necessarily mean your crop will fail. Look for resistant varieties labeled “TMV resistant” in seed catalogs. Reduce and prevent aphids, as these pests can spread the pathogen. Avoid using tobacco products near your crop, and be sure to sanitize hands and tools thoroughly before or after handling infected plants.

How Do I Improve Pollination?

Pollination can be improved by planting insectary flowers like calendula, dill, marigolds, alyssum, and flowering basil. These will attract bees to your beds. You should also grow these plants in an open, exposed area with moderate breeze. If you’re growing in a greenhouse, open the sides regularly to allow bees and wind inside. 

Do I Need To Hand-Pollinate My Tomatoes?

If there is an absence of bees or wind, you may need to hand-pollinate flowers to ensure a good fruit set. Use a little paintbrush to wiggle around inside each blossom. You can also gently grasp your plants from the tops and shake them to help pollen distribute inside flowers. Some people prefer to use the electric toothbrush method to vibrate the outside of the flowers, mimicking a bee’s activities. 

What Is Rust On Tomatoes and How Do I Prevent It?

Rust is an orange-spotted fungal infection that can be treated with diluted neem oil sprays or baking soda and horticultural oil. The fungus causes orangish-brown coloration to leaves, eventually leading to crispy texture and dead foliage. The blisters mostly appear on the undersides of leaves. It’s vital to remove infected foliage, sanitize your tools, and improve airflow with pruning.

What Is The Best Way To Control Spider Mites?

Tiny white mites with sticking webbing are a sure sign of spider mite infestation. Diluted neem oil or insecticidal soap are the easiest spray solution. You can attract predatory mites, ladybugs, and lacewings with insectary plantings like sweet alyssum and flowering dill. Keep the soil sufficiently watered to prevent the dry conditions these insects like. 

What Causes Calcium Deficiency In Tomatoes?

Contrary to popular belief, most garden soils have plenty of calcium, but the calcium isn’t always available. A soil test will tell you if calcium is present in your ground. Oyster shell, egg shells, and dolomite lime are natural amendments.

It is also important to ensure magnesium is present, as this affects the plant availability of calcium. Remineralization with a product like Azomite can be beneficial. Most notably, consistent moisture ensures that tomato plants can uptake these minerals. Avoid huge fluctuations from dry to wet roots.

Why Aren’t My Plants Growing?

Slow growth in tomatoes is usually due to transplant shock, compacted soil, or lack of sunlight. Take care to properly harden off seedlings and be gentle with their roots when planting. Amend soil with compost and improve aeration with a broadfork to ensure that the ground isn’t too compacted for young roots.

Plant in full sun locations without any shade from buildings or trees. Provide ample moisture during establishment to help them take off. Be patient, as shocked seedlings may take a few weeks to recover and start growing vigorously again.

How Do I Know If I Overfertilized?

The main sign of overfertilized tomatoes is yellow leaves with brown margins, beginning in the lower leaves. Slow growth and leaf drop can also demonstrate that a plant is suffering from fertilizer burn. You may see a crust of dried fertilizer on the soil surface. You may need to flush the soil with water or transplant the crop. To prevent this, avoid synthetic quick-release fertilizers. Instead, choose slow-release balanced products and only use a small amount at a time.

What Are The Most Common Tomato Diseases?

Early blight, late blight, Septoria leaf spot, bacterial wilt, and tobacco mosaic virus are the most common diseases. They all have distinct symptoms and solutions that you can learn about in this in-depth guide to identifying and treating tomato diseases. 

How Do I Prevent Sunscald?

Sunscald happens when fruits are burnt by excessive UV rays. It looks like burnt or discolored skins. Some leaf cover can be helpful to partially shade the fruit. Don’t prune off too much foliage, as this can leave fruit vulnerable to sunburn.

What Bugs Are Eating My Tomatoes?

Aphids, hornworms, spider mites, and fruitworms are the most common pests of this crop. Most of them can be prevented with biological control and companion planting. Neem oil and horticultural soap are easy organic sprays for controlling large infestations.

Why Are My Tomatoes Mushy and Mealy?

Mealy, mushy fruits can be caused by infrequent watering, imbalance fertilizer, improper harvest time, blossom end rot, or pest infestations. The best way to prevent weird fruit textures is to balance the irrigation and harvest before peak ripeness at the “breaker stage” of 40-60% color change. Ripening indoors ensures that the fruit is protected in its final stages, but it will still have all the same flavor as vine-ripened tomatoes.

Should I Refrigerate Tomatoes?

The refrigeration debate is a hot topic in the gardening and farming world. The truth is, refrigerated tomatoes don’t lose their flavor as long as they are ripened at room temperature first. Refrigeration slows down the ripening process and helps your fruits stay fresh for longer. However, it’s not a good idea to put unripe fruits in the fridge because they won’t have the proper ethylene exposure to fully ripen.

Did I Plant My Tomatoes Too Deep?

This is a unique crop that actually prefers deep planting because the species can form roots all along the vine. However, you don’t want to plant more than 50% of the stem underground because seedlings still need plenty of aboveground leaves to photosynthesize. If you accidentally planted too deep, you can easily dig up the plant and transplant it with more of the upper leaves and stem exposed to the sun. 

Why Are My Tomato Plants Dying?

Premature or sudden death of a crop is usually linked to extreme cold, heat, pest infestation, or disease attack. An unexpected frost or an infection with late blight may suddenly kill tomatoes practically overnight, and there is little you can do to revitalize them. But if your plants are dying from heat stress, pests, or water stress, shade cloth, natural sprays, and soil moisture can help them bounce back.