How to identify septoria leaf spot on tomato plants

At first, it’s just a few speckled leaves near the bottom of the plant — nothing to worry about, right? But soon, tan-to-gray circular spots spread, leaves turn yellow and drop, and your once-lush tomato plant starts to look bare as it struggles to produce fruit.

What causes it

Septoria leaf spot is caused by the fungus Septoria lycopersici, which infects the leaves, not fruit, of tomato plants. As the disease progresses, it moves upward, weakening the plant and reducing fruit production. The fungus thrives in warm, humid conditions and spreads when rain or overhead watering splashes fungal spores from infected soil or plant debris onto lower leaves. Insects, garden tools or even your shoes or pant legs can carry the infection from plant to plant.

How to solve septoria leaf spot

• Good airflow is key: Follow recommended spacing guidelines, and stake or cage tomatoes to improve circulation.
• Keep leaves dry by watering at the base of the plant and pruning lower leaves to prevent contact with the soil.
• Adding a layer of mulch helps prevent spores from splashing onto foliage during rain.
• At the first sign of infection, remove affected leaves immediately to slow the spread.
• At the end of the season, clean up all plant debris and rotate crops to prevent spores from overwintering in the soil.

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How to identify tomato leaf curl

Tomato leaves should be broad and vibrant, but sometimes they take a turn — rolling inward, twisting at the edges or looking oddly crinkled. Leaf curling (or leaf roll) can be puzzling, leaving you wondering whether it’s a sign of trouble or just a temporary setback.

What causes it

Leaf curling is a sign of stress, not disease, and symptoms typically appear first on lower, older leaves. It often shows up as the season shifts from the cooler weather of spring to the hot, dry conditions of summer. During extreme heat, 90 degrees F and above, tomato plants curl their leaves naturally to conserve moisture. Inconsistent watering — too much, too little, or irregular schedules — can also cause leaves to curl as plants struggle to regulate water intake. Indeterminate varieties tend to be more prone to leaf curl than determinate varieties.

How to solve tomato leaf curl

The best ways to prevent leaf curling are consistent watering and planting varieties less prone to leaf curl and heat stress, such as ‘Solar Flare’ or ‘Florida 91’. An application of mulch will help retain moisture and regulate soil temperature. And you can provide temporary shade during extreme heat waves (above 90 degrees F) to give plants a break from the intense sun.

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How to identify blossom end rot in tomatoes

Just as your tomatoes start to ripen, you notice a mushy, sunken spot at the bottom of the fruit. Blossom end rot starts as water-soaked spots on the blossom end of the fruit, then quickly darkens, sinks in and turns leathery. While there’s no saving the affected tomatoes, the rest of your crop still has a chance.

What causes blossom end rot?

Blossom end rot is caused by a calcium deficiency that happens when plants can’t absorb enough of this essential nutrient. It’s most common on early-season tomatoes or after an extremely dry period in summer. Even if the soil has plenty of calcium, inconsistent watering can make it harder for plants to take it up, leading to dark, sunken spots on the bottom of the fruit. Too much nitrogen, root damage from rough planting or fertilizer burn can also interfere with calcium uptake.

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How to solve blossom end rot in tomatoes

Consistent watering is key. Water deeply whenever the soil is dry. A layer of mulch helps retain moisture and regulate soil temperature, reducing stress on the plant. Avoid high-nitrogen fertilizers, and be mindful when planting to prevent root damage. If your soil dries out quickly, consider using soaker hoses or drip irrigation to maintain steady moisture levels. Since calcium uptake depends on healthy roots and a steady water supply, these simple steps can make all the difference in keeping your tomatoes firm and blemish-free.

Even the best-cared-for tomato plants can be plagued by problems once in a while. Diagnosing the culprit is the first step to a solution. Here are six common tomato plant problems that can crop up and what you can do to help avoid them in the future.

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Blossom end rot

When the bottom of a tomato blackens into a sunken, ugly, leathery spot, you’re looking at blossom end rot. It’s caused by insufficient calcium levels in developing fruit due to a lack of water, which prevents plants from taking in calcium. You can eat the fruit but may have to cut off a good portion of it.

What to do about blossom end rot on tomatoes

• Water regularly, and use a fertilizer that contains calcium.
• Apply a couple of inches of organic mulch to keep the soil evenly moist during the growing season.
• If it's still a problem check the soil's pH — a range of 6.5 to 7 is best. Too high or low and blossom end rot may crop up.

Tomato fruitworm

If you go out to harvest your tomatoes and see a black hole near the base of the fruit stem, that's a sign that tomato fruitworms (Helicoverpa zea) are around. Cut the tomato open and you'll see tunnels — you might even find the culprit there, too. Tomato fruitworm is a 1½- to 2-inch-long caterpillar that varies in color, so you'll see it in light green to brown or black with stripes running the length of its body. Once mature, the larva drops to the soil to pupate and in a couple of weeks emerges as a yellow-tan moth that starts the life cycle all over again by laying eggs on tomato foliage. The fruit is usually a mess once fruitworms have been visiting, so you won't want to eat it.

What to do about tomato fruitworm

• Interrupt the life cycle of tomato fruitworm by collecting infested fruit before the caterpillar emerges and sending it away in the trash.
• Till the soil in fall to try and expose overwintering pupae.
• Try Bt (Bacillus thuringiensis). It's an organic pesticide that's fatal to caterpillars and is safe to use on edibles. Just be sure to wash fruit thoroughly before eating. However, Bt can also kill butterfly larva, so use it sparingly if you know you have desirable caterpillars as well.

Tobacco hornworm

In early to midsummer, these big (up to 4 inches long!) caterpillars can quickly strip a plant of foliage and may sometimes even chew on green tomatoes. Small tobacco hornworms (Manduca sexta) are plain yellow or white with no markings. They gradually turn green, develop white stripes and the namesake "horn" on the last abdominal segment as they mature. Tobacco hornworms are the larvae of the sphinx moth.

What to do about tobacco hornworms

• If numbers are small, handpick caterpillars and drop them in soapy water to kill them.
• Grow sweet alyssum (Lobularia maritima), dill (Anethum graveolens) or Shasta daisy (Leucanthemum x superbum) to attract braconid wasps, which lay eggs on the tomato hornworm, parasitizing and killing it.
• Bt is also effective. Thuricide®, which contains the kurstaki strain of Bacillus thuringiensis, works well on tobacco hornworm and is safe to spray right up to harvest, but be sure to wash fruit well before eating it.

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Split or cracked tomatoes

When dry weather gives way to a rainy period or you've watered sporadically, cracks or splits show up in tomatoes — the sudden increase in water uptake by the plant makes the skin split. The tomatoes don't look good, but you can still eat them.

What to do about cracking and splitting

Tomatoes do best with 1 to 1½ inches of water a week. You can avoid cracked and split fruit by watering plants regularly throughout the growing season and applying an inch or two of organic mulch, such as straw or bark chips, to conserve water.

Cloudy spot

Late in the growing season you may come across tomatoes that look like this one. It's caused by stinkbugs feeding on the fruit. The spots are soft and spongy but superficial, so you can still eat the tomato.

What to do about cloudy spot

Are there weeds growing near your tomatoes? That's usually where these pests make their home, so if you get rid of the weeds, the stinkbugs will likely relocate and leave your tomatoes alone.

Catface tomatoes

This unusual-looking condition happens when flowers don’t develop properly. It’s usually caused by low nighttime temperatures (below 55 degrees) or strong winds. Catfaced tomatoes may look deformed, but they are still OK to eat.

What to do about catfacing

Shelter plants from strong winds and protect them from low temperatures by covering them at night with row cover or an old sheet.

Add heirloom tomatoes to your garden

Jennie Smith’s grandparents couldn’t imagine the number of different tomatoes their granddaughter would one day grow on their old farmstead in central Iowa. And they wouldn’t recognize the range of tomato colors, shapes, sizes and flavors we can choose from today. That’s because we have an astounding selection of heirloom varieties that have been preserved through the efforts of generations of gardeners just like Jennie, not to mention the modern hybrid tomatoes developed by plant breeders. But Jennie definitely has a preference for historical varieties of heirloom tomatoes.

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What makes heirloom tomatoes different?

Heirloom tomatoes, like other fruits, vegetables and flowers tagged with the “heirloom” label, are open-pollinated, meaning wind, insects or the plants themselves take care of producing the next generation. When there is no cross-pollination or genetic mutation, the result is offspring that look and, in the case of tomatoes, taste, just like their parents.

Indeterminate vs. determinate tomatoes

Most heirloom varieties are indeterminate, which grow long vines that produce fruit throughout the season until killed by frost. The best-tasting varieties tend to be indeterminate. A few heirloom plants do not sprawl all over the place. These tomatoes are called determinate varieties. Determinate varieties get to a certain size and then set their fruit more or less at once. Determinates may be a better choice if you want to grow tomatoes in a small space or in a container.  

Full sun, ample moisture and warm weather produce sweet and juicy fruit. Thanks to the preservation efforts of generations of tomato lovers, seeds and transplants of heirloom tomatoes are easy to come by online, at farmers markets and through mail-order sources. As a tomato pro, Jennie has tried lots of different heirloom varieties over the years, and shared 30 of her favorites below. Add some of these heirlooms to your garden and take a bite from the past.

Heirloom tomatoes in all shapes and sizes

Tomatoes are the number-one homegrown crop. And it’s no wonder: After all, what captures the feel of summer better than a sun-warmed, juicy, just-picked tomato? There are scores of varieties to choose from, so we asked Jennie to share some of her favorites. When deciding, keep the various sizes of the fruit in mind:

• Very small (1 inch or less)
• Small (1 to 1½ inches), medium (1½ to 3½ inches)
• Medium-large (3½ to 5 inches)
• Large (5 to 8 inches)
• Extra large (8 to 10 inches)
• Giant (10 inches and larger)

Heirloom tomato seed sources

• Baker Creek Heirloom Seeds, www.rareseeds.com
• Seed Savers Exchange, www.seedsavers.org

Beautiful heirloom tomatoes for your garden

Meet a beautiful mix of heirlooms from tiny cherry tomatoes to giant slicers, you'll be sure to find a few varieties you'll want to add to your vegetable garden this year!

Saving tomato seeds

If you want to grow your own heirloom tomato variety every year, you will need to know how to save tomato seeds at the end of each season. While you can simply scoop out the seeds and dry them, it’s better to use this fermentation process for "wet" seeds.

Does this process work for other seeds?

While I'm showing you how to ferment and dry tomato seeds here, this is also the best process to use for other "wet" seeds, such as cucumbers and melons.

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Save tomato seeds with fermentation

Tomato seeds are encased in a gel that contains a germination inhibitor. In nature, this ensures the seeds don’t sprout prematurely. A fruit that has fallen to the ground will naturally ferment and dissolve that gel. When you collect seed you have to artificially create those conditions. Let’s look at the steps needed to do this.

Choosing the right tomato to save seeds from

First, select a ripe tomato with a flavor, shape or size you like. Most old-fashioned heirlooms, such as Brandywine Pink and Brandywine Yellow, are good choices for seed saving because they are open-pollinated. Open-pollinated plants need wind, insects or water to perform the pollination among flowers on the same plant or variety. The fruits produce seeds that grow to be like the parent, as long as pollen from another variety didn’t fertilize the flower. Since tomatoes aren’t easily cross pollinated, you can prevent this by planting cultivars at least 25 ft. away from each other.

If this isn’t possible, to be sure you have an open pollination, seal a cluster of unopened tomato blooms in a paper bag. Every morning, give the bag a shake to move the pollen inside from flower to flower as they open. Once they’ve withered and fruit begins to form, remove the bag and label the cluster. Later, use the ripened tomatoes to collect the seed.

Avoid cross-pollination

In contrast to an open pollination, seed from cross-pollinating two different varieties is a hybrid. Seeds from a hybrid may grow into a plant completely unlike the parent, with a mix of traits from each side of the cross. These plants are usually less vigorous, as well, so you wouldn’t want to save those seeds.

Now that you have your tomato picked out, learn how to save and dry the seeds with the steps below.

Step 1: Scoop out the tomato

Wash the tomato then use a sharp knife to cut the tomato in half. You can scoop out the gel that contains the seeds with a spoon, or simply squeeze the tomato half to push out the pulp. If you don’t mangle the fruit too much, you can eat what’s left. I was able to fill each half-pint jar two-thirds full with seeds, gel and pulp from two tomatoes, which was a perfect amount to work with. Any less liquid and the pulp dries out and won’t ferment.

Step 2: Let the gel ferment

The tomato gel will need to sit indoors at about 70 degrees F out of direct light to ferment. You can leave the jars uncovered, but I used a coffee filter held on with a rubber band as a lid. This shaded the tomato gel, kept out contaminants, fruit flies and curious pets, plus allowed air and gas exchange during the fermentation process. It also provided a place to write the variety name — don’t forget to label your seeds so you know what you have!

Step 3: Separate the good seeds from the rest

Let the solution sit for up to three days. Any longer and the seeds may start to deteriorate. At that time, you’ll see a distinct separation, with pulp floating at the top, while good seeds have sunk to the bottom in the clear liquid. A layer of mold is nothing to worry about — that indicates the fermentation was successful. The photos below show you how it will look, and it may also smell a bit funky.

Step 4: Remove the scum

With a spoon, carefully skim off the top skin of mold and throw it away. As you do that, some of the viable heavier seeds that were tangled with the pulp will sink. Nonviable seeds will remain floating. Try not to disturb the tomato matter too much by shaking or bumping the jar so those bad seeds won’t get mixed in with the good.

Step 5: Rinse & repeat

Next, add ¼ to ½ cup of water to the remaining liquid with seeds and stir, as at far left below. Let it settle a few moments so good seeds will sink again. Pour off the top half of the liquid and floating seeds, leaving what you see in the middle photo. Repeat this two more times until the water is clear when you rinse and seeds are clean, as in the third photo. Pour them into a kitchen strainer to drain. You could also rinse them under running water in a strainer but nonviable seeds would be retained.

Step 6: Set the seeds out to dry

Spread the wet seeds out on a paper plate, coffee filter or screen to dry, scattering them as much as you can. Don’t use paper towels because the seeds will stick to that material like glue. They’ll cling together as well, so check them every day or two and rub the clumps of seeds between your fingers to separate them.

Step 7: Store the dry seeds

Leave the seeds to air dry for seven to 14 days in a warm, out-of-the-way spot, like on top of the refrigerator. When they’re dry, the seeds will appear a bit hairy or furry. Look closely to make sure that’s not mold, which would be white and damp. A properly dried seed will snap when bent in half. You can use a pair of tweezers to test this. Once they’re dried, place the seeds in a labeled envelope in a cool (40 to 45 degrees F), dark, well-ventilated place. You can also store them in an airtight plastic container, but be sure they are totally moisture-free to prevent mold from forming. Fermented and dried seeds will have a long shelf life — four to six years versus only one year for simple air-dried seeds.

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If you want to learn how to grow tomatoes in your garden and get tips on producing a prized harvest, my online course, Homegrown Garden: Harvest More in Less Space is the perfect place to start.

See also [2 Easy ways to preserve tomatoes](https://www.gardengatemagazine.com/articles/vegetables/tomatoes/2-easy-ways-to-preserve-your-tomato-harvest/ "2 Easy ways to preserve tomatoes")

Nothing is more flavorful than tomatoes at their peak, and these two recipes will preserve your tomatoes year-round. First, pick the best tomatoes from your garden to experience ultimate freshness. Then, follow these tomato recipes below that will surely excite your taste buds upon the first bite. Trust me — you’ll be using these fresh tomatoes all winter-long!

Are we getting ahead of ourselves? If you want to learn how to grow tomatoes in your garden and get tips on producing a prized harvest first, my online course, Homegrown Garden: Harvest More in Less Space is the perfect place to start.

Preserved Tomato Juice

What you'll need:

• Garden fresh tomatoes
• Food processor
• Fine strainer

How to make preserved tomato juice from your home grown harvest:

1. Slice garden-fresh tomatoes in quarters and add them to a food processor.
2. Pulse for 10 to 15 seconds.
3. Pour through a strainer, collecting the juice in a bowl.
4. Squeeze the tomato pulp dry to save for homemade tomato paste recipe below.
5. Save the juice and serve it fresh over ice, make a bloody Mary, freeze it for future parties or water bath-preserve to share as party favors and holiday gifts.
   

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Practical Tomato Paste

Tomato paste is the base of all things made from cooked tomatoes. Once you have separated the juice from the raw tomatoes, you can use the tomato pulp to make a delicious tomato paste. I like to roast the paste unseasoned so that it can be seasoned to taste when I use it in recipes.

How to make tomato paste:

1. 400 Degree oven — preheated.
2. Add tomato pulp reserved from making juice to roasting pan, depending on volume you can use a bread loaf pan for smaller amounts.
3. Roast for 45-60 minutes until paste is bubbling.
4. Cool to room temperature.
5. Freeze as roasted paste by adding servings to quart bags and laying flat so that, once they’re frozen, you can stand them on end. (You can also keep them flat, but starting flat to freeze ensures they aren’t lumpy or misshapen in the freezer.)

Let’s get started! Find more tomato recipes, get great tips on growing your best garden harvest possible and more in my online course, Homegrown Garden: Harvest More in Less Space.

If summer had a flavor, it would be that of a tomato. Raising these plump, juicy fruits is so satisfying. While tomatoes come in many sizes, shapes, colors and flavors, they all have one thing in common: They are either determinate or indeterminate. The difference between the two comes down to timing and size: More compact determinate tomatoes ripen all at once so they are ideal for going crazy making sauces, canning and freezing. Indeterminate types continue to grow all summer, so you can pick your fill one week, then pick again the next. It’s a good idea to plant both types so you can eat some and preserve some. Do you want to slice them for sandwiches, toss a few into salads or make pasta sauces? There’s a tomato best suited for each culinary situation. Learn about the four main types below.

Regular watering is important

Whichever type you grow, consistent soil moisture is key. Water plants deeply and infrequently at the base of the plant, not on the leaves, to prevent disease. Plants need 1 to 1½ in. of water a week. To maintain even soil moisture, mulch around the base of plants.

Need help getting started? Read [How to start a vegetable garden](https://www.gardengatemagazine.com/articles/vegetables/getting-started/how-to-start-a-vegetable-garden/).

Bush tomatoes

Ideal for small-space gardens or containers, bush tomatoes produce midsize, round tomatoes. The fruits are larger than cherries and have a flavorful, beefsteak attitude. Try ‘Early Girl’, in the photo above, and ‘Big Boy’ hybrids, which offer big taste on compact plants.

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Beefsteak tomatoes

Set your clock to BLT time. If you love classic bacon-lettuce-and tomato sandwiches, then beefsteak-type tomatoes are for you. Also known as slicers, beefsteaks produce large and wide fruit — a slice covers a piece of bread — and some are as big as 6 in. across. Try heirloom and hybrid varieties. ‘Brandywine’ is an heirloom, endorsed by generations of gardeners since 1885. These chubby, meaty tomatoes can weigh 1 to 2 lbs. and need 85 days to mature, so plant seeds indoors in spring or buy seedlings. Other heirloom beefsteak varieties include ‘Cherokee Purple,’ in the photo above, ‘Brandywine’ and ‘Mortgage Lifter.’ If you love the biggest-of-the-big beefsteaks, try Steakhouse Hybrid, which produces whopping 48-oz. fruits. Enjoy firm, red ‘Steak Sandwich’ on a toasted slice of sourdough with a slather of mayo and you’ll be in heaven.

Cherry tomatoes

Whether you sprinkle them into summer salads and pasta dishes or onto pizzas, tiny tomatoes are as tasty as they are cute. Grow them in the garden or containers and enjoy their colors (red, yellow, and blends) and shapes (round, oblong, and pear). ‘Sweet 100’ is known for its sugary flavor. Try small-fruited Indigo Fireball, shown in the photo above, for tart taste and yellow-purple skin or ‘Power Pops’ (with 55 percent more lycopene, an antioxidant that may help reduce your chances of developing some cancers, than the average tomato). Heirloom ‘Yellow Pear’ adds color and tang to summer salads.

Roma tomatoes

Known as the paste tomato, thick walled, oblong-shape romas aren’t as juicy as other tomatoes, which makes them excellent dried or diced up and simmered down into a sauce. For Old World flavor, try blocky heirloom ‘San Marzano’ in the photo above. And in the bigger-is-better category, ‘SuperSauce’ hybrid paste tomatoes weigh in at 2 lbs. apiece.