Category Archives: Tomatoes

Success with Heirloom Tomatoes

Heirloom tomatoes are the superstars of the vegetable garden world. They have endearing stories, gorgeous colors, unique shapes, and a flavor beyond compare. Unfortunately, all that flavor and charm comes with a cost. Heirloom tomatoes can be tricky to grow. Many heirlooms lack resistance to fungal and bacterial diseases and have thin skin that splits and cracks easily.

Despite this, we love them and wouldn’t trade them for all the hybrids in the world. They’re too good to resist. That’s why we’ve put together a list of management techniques to help ensure you have success with heirloom tomatoes. 

Protect the Foliage of Heirloom Tomatoes

Many common tomato diseases such as late blight, Alternaria (early blight), Botrytis, and leaf mold, thrive and spread in moist conditions. These fungal diseases produce spores that spread to tomato foliage through wind and water. 

In much of the Southeast, where we have hot, humid summers these diseases are prevalent. Thankfully, there are a few ways to shelter your heirloom tomatoes by protecting their foliage. 

Mulch

One easy way to protect your foliage is with a thick layer of mulch. This prevents soil splash-back onto the tomato’s foliage even during heavy rain. Plus, mulch helps keep the soil moist and prevents weeds.

You don’t need anything fancy. Straw, grass clippings, old leaves, and wood chips all work. For extra weed suppression, place your mulch over a layer of cardboard or newspaper.

In cooler climates, you may need to wait until the soil has fully warmed to apply mulch. Mulching too early can prevent soil warming and reduce early growth. 

Hoophouses

While not available to everyone, hoop houses are one of the best ways to prevent these wind and water-borne diseases. They keep the foliage dry all season and help block wind-borne spores.

Keep in mind that most heirloom varieties are large, indeterminate tomatoes. You’ll need a tall tunnel and a good trellising system.

Two Granny Cantrell’s German Red/ Pink Heirloom Tomatoes on the plant
Granny Cantrell’s German Red/ Pink Heirloom Tomatoes

Use Drip Irrigation, Hand Watering, or Soaker Hoses for Heirloom Tomatoes

Watering methods like drip irrigation or soaker hoses are preferable to overhead watering for heirloom tomatoes. These methods water the base of the plant, keep the foliage dry, and prevent soil splash-back.

If you only have a few plants and these methods aren’t accessible, watering the base of the plant by hand with a hose or watering can is also effective. Avoid using a hard spray which could splash soil onto the leaves.

Space Heirloom Tomatoes Generously

Improving air circulation can greatly reduce disease pressure in tomato plants. While some growers may plant tomatoes as close as one foot, we recommend planting heirlooms at least 2 feet apart in rows 60 inches apart. 

Trellis and Prune Heirloom Tomatoes

Proper pruning and trellising are other key ways to improve airflow and reduce disease pressure. Most heirloom tomatoes are vigorous, indeterminate plants that require sturdy trellises and more frequent pruning. 

Good trellis options include large homemade cages, the Florida weave method, tall stakes, or string systems in hoop houses.

Several common trellising methods are easiest when you prune the plants to a single leader. Pruning to remove suckers also allows more airflow and can encourage good production. 

Learn more about proper pruning here

Two Old German Tomatoes on a plate with some slices
Old German Tomatoes

Learn to Identify Common Diseases

Learning to spot common diseases can help you catch problems quickly and take the appropriate steps. If you buy in plants, it may also help you spot signs of disease before you bring it into your garden.

Cornell University has an excellent Tomato Diagnostic Key for identifying diseases. 

If your tomato has a fungal disease like late blight, removing and destroying affected foliage and plants can help slow the spread.

Some growers, particularly commercial growers may also consider using organic fungicides. Like any treatment, they have downsides and should be carefully researched and applied. 

Johnny’s Selected Seeds has a handy chart of organic treatments for pest and disease issues. 

Learn to Spot Nutritional Deficiencies

The issue with nutritional issues is twofold. First many nutrient issues are easy to mistake for disease issues. Before you go spraying fungicide, make sure that the yellowing you’re seeing isn’t just a nutrient deficiency.

The second issue is that nutrient deficiencies stress the plant which can make it more susceptible to disease in the future. Just like you have a stronger immune system when you eat well and get enough sleep, your plant will fight off diseases better when it’s well cared for and nourished. 

Here are common nutrient deficiencies we see in all plants and how to correct them.

Manage Water Carefully

Heirloom tomatoes thrive with consistently moist, but not waterlogged soil. Their thin skin means that large fluctuations in moisture can lead to splitting.

Too little water can also cause issues like blossom end rot. While this disease is caused by a lack of calcium, often the root cause is a lack of water. When the soil is too dry, the plant can’t take up enough calcium, even if it is present in the soil in sufficient quantities.

Overwatering can also dilute the flavor of tomatoes and contribute to disease issues. 

When determining whether you need to water, dig down a couple of inches and feel the soil. It should be moist but not so wet you can squeeze water out of it. 

Purchasing a cheap moisture meter can simplify this process and help remove any doubts about when to water.

Rotate Crops by Family

Many diseases that plague heirloom tomatoes are soil-borne, so proper rotation is critical. We recommend rotating your crops on a four-year cycle. For commercial growers, adding a year in cover crops is also a good idea. 

When rotating crops, do so by family, not just species. For example, don’t rotate just tomatoes. Rotate the nightshade or Solanaceae family including tomatoes, peppers, tomatillos, ground cherries, eggplants, and potatoes.

Abraham Lincoln (Early Abe Lincoln) Heirloom Tomatoes spilling out of a basket
Abraham Lincoln (Early Abe Lincoln) Tomato

Select a Variety Wisely

Each heirloom variety we carry has its own unique set of strengths and weaknesses. A few carry resistance to specific diseases. You’ll find their disease resistance listed in parentheses after the variety name. 

For example, the Abraham Lincoln (Early Abe Lincoln) Tomato has (ab, asc) next to its name. This indicates that it’s resistant to Alternaria (early blight) and Alternaria stem canker. 

See our full key to tomato disease tolerance.

Note that many heirloom tomatoes have not been extensively tested for disease tolerance either in the laboratory or in extensive field trials. The absence of disease resistance information in the variety description does not imply a lack of resistance. 

You can also consider heirloom cherry and paste tomatoes. These usually display more disease resistance than large, slicing tomatoes.

If all else fails, we carry many disease-resistant, open-pollinated varieties. While they may not be considered heirlooms yet, they still have delicious flavor. By saving seed from one of these varieties, you can help create a legacy for one of these newer varieties. 

Tomato Tips: Preventing Fungal Diseases

For many tomatoes are the highlight of the summer garden. The refreshing sweet yet acidic flavor of a garden tomato is world’s away from the bland, mealy supermarket tomatoes of winter. Unfortunately for those living in areas with hot, humid summers getting a good tomato harvest can be a struggle. Many times tomatoes can become afflicted with fungal diseases like Verticillium wilt, Fusarium wilt, or Alternaria.

Alternaria also known as early blight causes “bullseye” leaf spots and can causes lesions on the fruit. Fusarium wilt causes the plant’s leaves to wilt and turn yellow and then brown. It usually begins on the plants lower leaves. Like Fusarium wilt, Verticillium wilt begins at the bottom of the plant causes yellow spots to form on the leaves before the leaves turn fully yellow or brown.

There are also many other tomato afflictions you could be experiencing in your garden these are just a few common ones. 

Don’t handle your tomatoes when they’re wet.

Fungal diseases are passed through moisture. Avoid working with your tomato plants until after all the dew or rain had dried off.

Use drip irrigation.

Using drip irrigation is more efficient and can help limit the spread of fungal diseases because the water is going directly to the plants’ roots. For those with small gardens, it’s also possible to spot water the base of the plant. If you must use overhead watering water in the early morning so that the plant will have time to dry off during the day.

Tomato trellis of string weaving at Twin Oaks Community Farm

Prune, trellis, and weed around your plants.  

We all start each spring with the best intentions but often the summer gets away from us. It can be easy to fail to keep up with these important tasks when our garden is competing for our attention with work and family obligations. However, maintaining good airflow around your plants is vital to preventing fungal diseases.

Tomatoes can be trellised in a variety of manners like the “Florida weave” pictured above, on cattle panels, or some sort of homemade tomato cage.

Rotate your crops.

Many fungal diseases that afflict tomatoes live in the soil. To keep your tomatoes disease free you must rotate your crops. Don’t plant tomatoes or other nightshades (including potatoes, peppers, and eggplants) in the same space multiple years in a row. You should use a minimum of a four-year rotation.

Keep your soil and plants healthy.

Along with rotating your crops, you should also work hard to improve your soil’s health which will help you grow healthier, less vulnerable plants. Get your soil tested and add amendments as needed. Practice no-till agriculture. Use cover crops and good quality compost to add fertility and organic matter to your soil. Mulch pathways and around plants to add organic matter and habitat for beneficial fungi and microbes.

West Virginia 63 (Centennial) Tomato – resistant to late blight, Fusarium wilt race 1, Verticillium wilt, and sunscald

Plant disease resistant varieties.

Some varieties have been specifically bred to better tolerate these diseases. Check out our disease resistant selection.

Try a fungicide.

If all else fail you can find organic fungicides. Look for those that are OMRI (Organic Materials Review Institute) listed. Keep in mind that organic doesn’t always mean completely harm-free. Many fungicides will kill off your soils’ good fungus as well as the bad. Some fungicides like copper can even cause toxicity in your soil if used too frequently or in high quantities! Some gardeners have luck with products like Mycostop which are created from bacteria that feeds on the fungus.

Having tomato diseases ruin your harvest can take a lot of the fun out of gardening. Try following these tips to keep your tomatoes disease free this year.

 

Top Tips for Terrific Tomatoes

Georgia Streak Tomato

For many gardeners, it’s hard to picture a world without tomatoes. These productive plants steal the show in many backyard gardens with their wide variety of shapes, colors, and flavors. While the Aztecs grew tomatoes since before 700 A.D. they were not known internationally until the 16th century. Even then, they were regarded with some suspicion as a colorful member of the nightshade family. It’s amazing how quickly they’ve become important worldwide. 

Try disease-resistant varieties.

If you struggle with blight and other diseases wiping out your tomatoes before you get a proper harvest you may want to consider planting a few disease-resistant varieties. 

Plant them deep.

Transplanting tomatoes properly is a little different from many other vegetables. Rather than bury them at the same depth as they were in the pot you can bury them deep enough to cover their bottom set of leaves. You’ve probably noticed how the bottom of a tomato stalk is covered in little bumps. Those bumps are nodes which send out roots when they’re covered in soil. Burying them deeply so they can quickly produce more roots will help your plants thrive. 

Tomato trellis of string weaving at Twin Oaks Community Farm

Set up a large, sturdy trellis. 

Store-bought tomato cages may be sufficient in far northern climates or for some determinant varieties but for the most part, especially in the southeastern United States, your tomatoes will quickly outgrow them. Many people opt for the “Florida weave” technique pictured above which requires stakes and twine. Another great option is cattle panels. 

Provide good compost. 

Tomatoes are heavy feeders and providing them with plenty of nutrition can help them do their best. Add a scoop of compost to the bottom of your transplant hole and watering them in with compost tea can help them do their best. Once they flower you can side dress them with more compost or water them again with compost tea. 

Use mulch. 

Using some sort of mulch around your tomatoes is highly recommended. It will help block weeds and ensure your tomatoes have good consistent moisture, needed to fruit. 

Try succession planting.

Often when people think of succession planting they think of crops with a single harvest like carrots and beets or a relatively short harvest like sweet corn. However, there’s no reason you can’t do it with tomatoes if you have a long enough season. At SESE we transplant some of our tomatoes as late as July so that we have a wide selection available for our August open house and the Heritage Harvest Festival in September. 

Transplanting Tomato Seedlings

You can also grow storage varieties so that you have fresh tomatoes in winter too!

Every plant comes with its own challenges and tomatoes are no different. These six tips can help ensure you get an awesome tomato harvest this year.

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