The Definitive Guide To Caring For Tomato Plants

Caring For Tomato Plants - Garden Vegetables - That’s one huge tomato (Photo by Erich Boenzli) — That’s one huge tomato (Photo by Erich Boenzli)

The Definitive Guide to Caring for Tomato Plants

In my humble opinion, nothing tastes better than a tomato right off the vine, still warm from the sun. As a kid, I would walk into our backyard garden, pluck a ripe tomato, grab a salt shaker, and enjoy one of these juicy treats of summertime.

Still today, I can hardly resist munching on these sweet treats right in the garden...they rarely make it all the way into the kitchen. Especially little grape and cherry tomatoes, which almost seem to be asking to be devoured right then and there.

In order to enjoy these pleasures, however, we have to know how to care for our tomato plants so they’ll produce these tasty gems all throughout the season. No worries! I’ll guide you through everything you need to know, from general care, to diseases & pests, and even a video showing you how to prune your tomato plants!

Caring For Tomato Plants - General Care

Keep tomato leaves dry, whenever possible. Water plants down at ground level, not from above. This will help prevent some diseases.
Plant your tomatoes in a different spot each year, as some tomato diseases can overwinter in the soil and infect your new crop.
Prune tomatoes, both to remove diseased leaves and to provide better air circulation (more information in video below).
Mulch tomato plants with wood chips or straw. This will help control weeds, retain moisture, and prevent any bacteria from splashing up onto your plants during watering and rain.
Ensure that your tomato plants get 1-2 inches of water per week, whether from rain or watering them yourself.
Stake or cage tall plants, to keep fruit from rotting on the ground.
Leaves turning yellow may either may be a sign of overwatering or disease (see below).
Organic Neem oil may be used on tomato plants to combat pests, fungus, and mildew.

How To Prune Tomatoes

Pruning tomato plants serves several purposes. Removing any diseased leaves and branches helps keep the disease from spreading further in the plant. Also during this time, you can check for any pests. Pruning off suckers helps ensure that the plant is getting enough air circulation so it doesn’t get damp (which can harbor disease) and also lets the plant focus more attention on growing big, beautiful fruits.

Learn how to prune your plants here:

Common Tomato Diseases

Early Blight (Alternaria)

Tomatoes - Early Blight (Image courtesy of University of Minnesota Extension) — Early Blight (Image courtesy of University of Minnesota Extension)

About

A fungal disease, spreading via spores.
Produces “bullseye” type, brown to black spots. Leaves may also turn yellow around these spots. When severe, leaves and branches will turn brown and fall off.
Will often start at the bottom of the plant and move its way upward.
Pathogen can overwinter in the soil.
Plants will most likely still continue to produce, but fruit may be infected (identified by black ridges near the stem)
Can also infect other plants, including potato and eggplant.

Care & Prevention

Select resistant varieties of plant.
Remove infected leaves from plant, and remove entire plant in the fall.
Treat with a fungicide.
Rotate crops each year.
Water from below.
Prune & stake plants to increase air circulation.

**Late Blight (Phytophthora infestans)**

Tomatoes - Late Blight (Image courtesy of Cornell University) — Late Blight (Image courtesy of Cornell University)

About

A fungus-like disease, spreading rapidly via spores.
Green/grey/black splotches on leaves, eventually turning brown. May also see white powdery spots on leaves.
Fruit will develop brown/black spots and will quickly rot.
Pathogen can overwinter in soil.
May spread to other plants, including potatoes

Care & Prevention

Select resistant varieties of plant.
Remove infected leaves from plant, and remove entire plant in the fall.
Use fungicide as prevention; but if plant is infected, must be removed & destroyed immediately to prevent spread.
Rotate crops each year.
Water from below.
Prune & stake plants to increase air circulation, as this pathogen will grow in damp conditions.

**Fusarium Wilt (Fusarium oxysporum)**

Tomatoes - Fusarium Wilt (Image courtesy of Seminis) — Fusarium Wilt (Image courtesy of Seminis)

About

A fungal disease, spreading via spores.
Leaves and branches will turn yellow and wilt, possibly only on one side of a branch or leaf near the bottom of the plant. It will progress throughout the plant, until eventually the entire plant collapses. By cutting into stem, you can see dark red/brown tissue underneath.
Pathogen can overwinter in soil for several years.
Can also infect other plants, including peppers and eggplant.

Care & Prevention

Select resistant varieties of plant.
Rotate crops each year.
Once infected, entire plant must be removed & destroyed.

Mosaic Virus

About

Two types: Tomato mosaic virus (ToMV) and tobacco mosaic virus (TMV), closely related, a pathogenic virus, spread worldwide.
Causes yellow, misshapen leaves.
Can infect other plants, including pepper, potato, apple, pear, cherry, cucumber, lettuce, and beet.
Can overwinter in soil in infected plant debris and roots.

Care & Prevention

Select resistant varieties of plant.
Rotate crops each year.
Once infected, entire plant must be removed & destroyed.
Smokers should wash hands with soap and water after smoking, as virus can spread from infected tobacco on hands.

Septoria Leaf Spot (Septoria Lycopersicon)

Tomatoes - Septoria leaf spot (Image courtesy of Missouri Botanical Garden) — Septoria leaf spot (Image courtesy of Missouri Botanical Garden)

About

A fungal disease, spreading via spores.
Starts as tiny dark round spots with white/grey centers on lower leaves, eventually turning yellow and brown before falling off.
Thrives in damp conditions.
Pathogen can overwinter in infected debris in soil, and even on cages.
Can also infect other plants, including potatoes and eggplant.

Care & Prevention

Select resistant varieties of plant.
Remove infected leaves from plant, and remove entire plant in the fall.
Treat with a fungicide.
Rotate crops each year.
Water from below.
Prune & stake plants to increase air circulation

Blossom End Rot

About

Can affect tomatoes, eggplants, squash, peppers, cucumbers, and melon.
Caused by calcium deficiency, often due to fluctuating moisture in the soil.
Identified by a dark, leathery, decayed spot

Care & Prevention

Keep soil pH around 6.5.
Add crushed egg shells or bone meal to fertilizer, to add calcium.
Use a high-phosphorus, low-nitrogen fertilizer.
Avoid overwatering plants.
Mulch plants to help maintain uniform moisture.
Remove damaged fruit; the rest of the fruit on the vine is fine to eat

Tomato Pests

Hornworm (Manduca quinquemaculata)

Tomatoes - Hornworm (Image courtesy of The Old Farmer’s Almanac) — Hornworm (Image courtesy of The Old Farmer’s Almanac)

A large caterpillar of the Five-Spotted Hawk Moth (Manduca quinquemaculata), also known as the Sphinx Moth or Hummingbird Moth.
Large, with 7 to 8 diagonal white stripes, horns on back end, green that blends in with plant foliage.
Can also affect other plants, including peppers, eggplant, potatoes, and tobacco.
Look for chewed stems, leaves, and fruit; and missing leaves; they can defoliate the entire plant.
May be parasitized by other insects; cocoons will look like white rice on the worm, which will eventually kill it.
To remove, manually handpick hornworm from plants & drop into soapy water (they don’t sting or bite).

**Aphids (Aphidoidea)**

Tomatoes - Aphids (Image courtesy of University of Maryland Extension) — Aphids (Image courtesy of University of Maryland Extension)

Tiny, pear-shaped insects, in a variety of colors.
Affects a wide variety of plants.
Suck sap from the plant and leave behind a “honeydew,” which will then turn into a sooty mold. This “honeydew” attracts bees and ants.
Look on undersides of leaves, where these insects like to hide.
They’re a favorite meal for ladybugs, lacewings, & parasitic wasps.
Can apply a mixture of soap & water or organic Neem oil to kill these insects.

Flea Beetle (family Chrysomelidae)

Tomatoes - Flea Beetle (Image courtesy of University of Minnesota Extension) — Flea Beetle (Image courtesy of University of Minnesota Extension)

Tiny, shiny beetles that jump like fleas when disturbed.
Affects a wide variety of plants.
Chew small pits and holes in leaves and stems
Can apply organic Neem oil to kill these insects.

Happy Gardening!

Want to grow other delicious veggies too? Check out these articles:

Try some of our delicious recipes with tomatoes:

Are you caring for tomato plants in your garden this year? Let us know in the comments below!

Do your friends enjoy yard & garden articles too? Share this article with them and let us know what you all think by commenting below!

Tag your photos with #maplewoodroad on social media and share them on our Facebook page! Have any questions? Ask on our Maplewood Road Community Facebook page and I’ll be happy to help. 😊

Subscribe to our weekly newsletter for more great yard & garden articles!