Blossom-End Rot: Diagnosing and Prevention

There’s nothing worse than walking out to the garden, seeing a bright red tomato ready for picking, only to discover a big ugly black bottom! What is this unsightly thing? It’s likely you’ve found yourself battling blossom end rot. This is a common disorder that happens mainly in tomatoes, peppers, zucchini, and melons. This disorder is caused by a lack of calcium, NOT insects, so don’t rush to apply insecticide on your garden.

Blossom end rot on tomatoes in various stages

Typically this disorder is caused by inconsistent watering, which makes it hard for the plant to take up the calcium from the soil. When a season starts out wet and then begins to dry when the fruit is setting, the fruit will show a dark brown areas on their bottom side that will eventually turn dark and leathery. If left alone, they will eventually begin to rot, so the fruit should be picked and discarded.

What causes Blossom End Rot?

Simply put, BER is caused when the plant lacks the calcium they need to produce fruit. However, this issue doesn’t typically pop up because the soil is calcium deficient. There are a couple of factors that can limit a plant’s ability to absorb calcium

-          Inconsistent watering

-          Excess nitrogen in soil

-          Root damage

-          Cold soil

In some cases, rapid growth can be the issue as well. I believe that this is my problem them year. My garden tomatoes completely took off during the month of June and tripled their size! When this happens, sometimes the plant grows faster than its ability to take up the calcium, which is needed during active growth.

Prevention

If, like me, you live in a cold climate, it’s best to plant after you know the last frost has come and gone. Cold soils can limit nutrient uptake, as well as damage the roots. Once the weather has warmed up, and your plants are happy in their new beds, making sure you have a good watering schedule is crucial. Watering thoroughly once or twice a week and using a mulch if necessary to keep the moisture in.

Sometimes, a certain variety or string of genetics are just more prone to BER, so it never hurts to keep good garden records to see which plants are giving you issues.

Once your plants are established, avoid using a rapid growth fertilizer and opt for slow release fertilizers instead. Adding some bone meal or a foliar calcium fertilizer can help the plant make up for the calcium deficiencies.

So, if you’re wandering through the garden and find that your disposing of tomatoes faced with Blossom End Rot, don’t despair. It isn’t a bacterial or fungal issue – you still have plenty of time to nip it in the bud and produce a bountiful harvest!