Knowledge from Olle Garden Bed: Why Your Tomato Plants are Hollow

Tomatoes are a favorite choice for home gardeners! After planting tomato seeds, the delicious fruits are usually ready to be harvested in 52 to 90 days. So, after nurturing your tomato plants with care and looking forward to a bountiful harvest, it can be disappointing to find hollow tomatoes when you cut them open! Several factors contribute to the formation of hollow fruit on tomato plants. Discover the culprits behind hollow tomatoes and get tips on how to prevent them.The following content also has some reference value for raised garden beds.

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1.Lack of Pollination

When tomato flowers fail to self-pollinate correctly, fruits can develop hollow spaces. This condition can make tomatoes look similar to bell peppers. A hollow tomato appears normal on the outside until you cut into it, revealing an interior that resembles the way bell peppers form.

Tomato plants are self-pollinating, meaning each flower contains both male (anther) and female (stigma) reproductive parts. For successful pollination, pollen must move from the anther, where it's produced, to the stigma below.

Pollinators such as wind and bees help move the flowers and their pollen, promoting self-pollination of the flowers, which results in fruit formation. Poor pollination quality due to adverse temperatures or improper fertilization can affect fruit set.

2.Temperatures Influence Pollination

Unusually hot or cold temperatures can disrupt pollination. Chilly temperatures below 55 degrees Fahrenheit hinder tomato plants and reduce pollen fertility. On the other hand, heatwaves, with temperatures reaching 88 to 90 degrees Fahrenheit, can cause flowers to drop before pollination can occur.

3.Excessive Nitrogen Fertilizer Prompts Flower Drop

Improper fertilization practices can also negatively affect fruit set in tomato plants. Nitrogen (N) is essential for the healthy foliage of tomato plants. When tomato plants experience a nitrogen deficiency, the entire plant changes from vibrant green to yellow.

However, over-fertilizing with nitrogen promotes rapid foliage growth and results in blossom drop, reducing pollination. To avoid this issue, apply fertilizer to tomatoes properly. Wait until the first fruits have appeared, then apply ½ cup of 46-0-0 fertilizer for every 100 feet of tomato plants in a 6-inch strip alongside them. Apply the fertilizer directly to the soil, 4 to 6 inches away from the plant's base (to prevent fertilizer burn) and work it into the soil's surface using a trowel.

4.You're Growing Stuffed Tomatoes

Don't forget to check the type of tomatoes you are growing. Varieties like "Yellow Stuffed," "Red Stuffed," and "Green Stuffed" are naturally prone to developing hollow fruit. When you cut into a stuffed tomato, it may look like someone scooped out the seeds directly! These varieties are a great choice if you enjoy stuffing tomatoes for recipes and baking. So, if you're growing stuffed tomatoes and they turn out hollow, it's a good sign that your tomatoes are growing as expected.

5.Your Tomato Plants are Infected

If the stems of your tomato plants are hollow on the inside, it's a cause for concern. Hollow stems are a sign of pith necrosis or bacterial soft rot (Erwinia carotovora subsp. carotovora) infecting tomato plants. Bacterial soft rot thrives during mild and rainy weather, so it often infects plants in the spring.

Symptoms of Bacterial Soft Rot

Look out for signs of infection, such as brown or black patches forming around the stems near the leaves or at the base of the plant. As the bacteria spread, water spots can also form on the fruit, making it smell like rotting produce as it breaks down from the inside.

The advancing bacteria take over the interior of the stems, causing symptoms such as the stems appearing shriveled or collapsing inward. Eventually, the entire tomato plant may wilt, as the stems become increasingly hollow, losing their ability to provide adequate support.

Managing Soft Rot in Tomatoes

Bacterial soft rot bacteria thrive in the spring, so sometimes, as temperatures rise, plants can recover. Support the recovery by irrigating the soil near the base of the plant. Watering helps promote healing by replenishing the water lost due to the infection. However, if the plant dies, be sure to completely remove it from the garden to reduce the risk of further spread.

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Preventing Soft Rot

Bacterial soft rot is challenging to eliminate because it can survive in the soil for up to three years. To avoid recurring infections, practice crop rotation (planting different types of vegetables) in that section of your garden in the next planting season.

Choose a different location for your tomatoes. Leave 3 feet of space between them to increase airflow and reduce the risk of bacterial spread during the spring rains. Bacterial soft rot bacteria also prefer cooler weather, so wait until the soil temperature is at least 55 degrees Fahrenheit before sowing tomatoes outdoors to avoid infection.

Cracking the Case of Hollow Tomatoes

If your tomato plants produce hollow fruit, identifying the root cause is crucial! Some varieties are naturally hollow, such as "Yellow Stuffed" or "Red Stuffed" tomatoes, so there's no cause for concern. However, it may indicate issues with pollination or bacterial soft rot infection. Reduce the chances of pollination issues by proper fertilization. Then, sow tomato seeds outdoors when the temperature is at least 55 degrees Fahrenheit to minimize the risk of bacterial soft rot damage to your plants.