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Blossom End Rot & Poor Pollination Solutions

Is it blossom end rot rotting your crops?

If you’re asking yourself “why are the bottoms of my tomatoes black”? Or if you’re wondering how you fix black bottoms on tomatoes, what’s causing your veggies to rot may be blossom end rot. And we’ll get into how you can fix black bottoms on tomatoes in this article. Plus, we’ll talk about whether you can eat tomatoes with black bottoms.

Moreover, if other veggies are turning black in your garden, we’ve got some helpful information to turn more than just tomatoes around!
Ripening Blossom End Rot Tomato

Black ends on crops might be something else besides blossom end rot.

And in order to fix any gardening problem, it’s important to be sure you know that you’re addressing the right thing! So we’ll cover another problem – poor pollination – as well.

Losing veggies we’ve worked so hard to grow is frustrating.  So when we find these shriveled fruits and blackening ends, it’s hard not to be dismayed.

So get read to learn causes and fixes for blossom end rot. And we’ll talk about ways to find more success if you find poor pollination is actually the problem in your vegetable garden.

Crops with black ends have two very common culprits:

Two very common issues result in the flower-end of your homegrown edibles turning brown and shriveling. These are blossom end rot and poor pollination. But, each issue has a different cause. As well, understanding those causes is the key to remedying the issue before the season passes and your entire crop is lost. And, yes, there are ways to get past both problems during the growing season. Plus, there are ways to keep them from repeating in the future.

Does end rot happen only on tomatoes?

Crops rotting on their ends can happen to many different homegrown vegetables. So, it isn’t just your tomatoes that might have a problem. But, before you buy a “rot stop” product, be sure you know if that’s going to be the right thing to deal with your garden’s issues.

What poorly pollinated “black rot” looks like:

  • Here are two zucchini fruits.
  • And you’ll notice the tiny one is shriveling. This is due to poor pollination, not blossom end rot.
  • But the large one was well pollinated. And that leads to a rapidly growing squash fruit.

Example of poorly & well pollinated zucchini fruits

This is what blossom end rot looks like:

  • These are tomatoes that have been successfully pollinated. And we know this because the fruits are fully formed.
  • But, after fully forming, one of the bottoms has begun to turn black. So we recognize the problem as blossom end rot.
  • However not every fruit in a cluster may exhibit the problem. In fact, some may hide the problem on the inside. And you’ll only see the blossom end rot when you cut the tomato open.
  • But some in the cluster may not have the problem at all.

Tomatoes with Blossom End Rot

How do I fix end rot in my garden?

Next up are some tips to remedy blossom end rot and poor pollination. Not only can you work on blossom end rot during the growing season. But we’ll also consider ways to fix blossom end rot on your tomatoes and other crops for years to come.

And we’ll get into some tips to help you hone in on which problem is happening. This includes considering timing, how plants grow, and what you can do to fix the main cause of blossom end rot and similar-looking crop problems.

When are you seeing black, rotting tomatoes or other fruits?

Considering when you’re seeing “black rot” on your crops is very helpful. That’s because poorly pollinated fruits show earlier than blossom end rot. As well, there are some other keys to consider as well when it seems the “end rot” is happening due to poor pollination. For instance:

  • Squash & its relatives often suffer from poor pollination.
  • And these plants have flowers that are either male or female. But only the females will have poor pollination problems. That’s because the females are the fruit-bearing parts.
  • Within a day of the flower opening, bees pollinate it. And the fruit will begin to grow immediately.
  • However if the squash flower isn’t pollinated, a fruit will begin to yellow & shrivel quickly. And sometimes it will turn brown or black at the flower end over time. And this can mimic the look of blossom end rot.

See the zucchini images above for black rot caused by poor pollination.

Tonda panada squash ready for pollination

How can you fix poor pollination on squash plants?

If poor pollination is causing black rot on your squash, zucchini, melons or pumpkins, the way to fix it is to improve pollination.

Easy ways to increase pollination in your vegetable garden:

  • So stop applying pollinator-detrimental ‘cides.
  • And don’t use any blossom end-rot products to try to fix crops that don’t have end rot. That’s because they probably won’t help.
  • And add some plants nearby that pollinators love.
  • As well stop overhead watering when female flowers are open. That’s because many squash tend to open flowers early in the day & close the flowers by early afternoon. And most female squash flowers only open for a day.
  • So if you apply overhead water during this time, bees may choose to do their work where “rain” isn’t plopping on them. And that means your flowers won’t be pollinated. Plus if the flowers fill with water, it can be more difficult for bees to do their job.
  • Finally, consider hand-pollinating your plants.

Poorly pollinated squash

Is the main cause blossom end rot on your tomatoes?

A common misconception is that blossom end rot is caused by plants being unable to access needed calcium.

In truth, some soils are known to be deficient in calcium. However, sometimes soil may have sufficient calcium, but other parts of the soil science are such that plants can’t access needed calcium.

More importantly, scientific research is showing that calcium deficiency may not be the cause of blossom end rot. In fact these studies indicate that blossom end rot may actually be due to environmental stresses like watering, light, and other challenges.

Can tomatoes recover from blossom end rot?

The findings also indicate that blossom end rot will likely turn itself around following the demise of the first few fruits to ripen on your plants. And in our non-scientific experience of growing tomatoes for decades, this seems to be the case. What happens is the first tomato or two to ripen may have blossom end rot. But the fruits that follow those don’t succumb to the problem.

Should I add calcium to my soil just in case?

Likely, adding calcium may not help. And it could hurt.

That being said, if your soil is deficient in calcium, adding it may be helpful. However, be sure you know if it is needed first.

Moreover, keeping balanced soil nutrition year over year and a carefully curated tomato garden plan seems to help our plants avoid getting the problem at all.

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But in order to know your soil’s calcium status may mean you need to get a soil test. And if you want to learn more about soils with us, be sure to sign up for FREE to get information about our online gardening education programs.

What kind of tomatoes get black rot?

Just about any tomato can get black rot. However, some varieties of tomatoes are more likely to develop end rot than others. In our experience, paste and sauce tomatoes seem to be more susceptible than other kinds of tomatoes.

What more can you do to deter blossom end rot?

One of the best things you can do for your vegetable garden is to test the soil. That’s because when you get a soil test, you know how to keep your garden soil balanced for any crop – including tomatoes without blossom end rot!

Also, don’t fertilize unless you know your garden needs it. That’s because over-fertilization can be wasteful. And it can create soil nutrient imbalances that further compound any problems like blossom end rot. Plus unused fertilizer can create soil and water contamination problems as well.

In addition you might try adding egg shells to your soil. That’s because adding egg shells, shellfish shells, and bone meals to your soil can help raise your calcium levels. However, it takes a while for these shells to breakdown and release calcium to the soil. So adding them may not help things turnaround on a fruiting plant. But adding them consistently over time can help year after year. And so can liming your soil.

But, again, get a soil test before trying to adjust your soil to deal with blossom end rot. Otherwise you might be wasting energy and garden additives. And you might be causing more problems than solutions.

Finally, try to plant your tomatoes in a spot where they receive full sun consistently throughout the day. And water your plants consistently. Overwatering may cause your tomatoes to get blossom end rot; under watering may do so as well. This is likely because it adds stress to the plants.

Consider this month-by-month tomato growing plan that we use to help maximize our tomato growing.

But, can I eat tomatoes with blossom end rot?

Since it’s likely that only the first few tomatoes on the vine will get end rot, you may choose to remove any that are showing signs of end rot. That’s because your plants will exert precious energy on these nasty bits instead of on less damaged ones if you let them continue to ripen on the plant. So by removing them early, the plant can maximize the goodness of the healthier tomatoes.

Finally, you can eat tomatoes with blossom end rot. In fact, you may find some blossom end rot hiding inside a tomato that doesn’t have a black bottom on the outside.

If you’re going to eat a tomato with blossom end rot, cut out any rotten part and throw that away first.

8 comments on “Blossom End Rot & Poor Pollination Solutions

  1. Garden Mentors on

    Sheila, your tomatoes should start ripening as they mature. That being said, without knowing the details, it’s hard to help explain why they aren’t. If it helps, here in the PacNW, our cherries have been ripening for several weeks. But, our larger varieties that were seeded at the same time as the cherries, are still green. Different varieties and sizes take different lengths of time to ripen. Too, location and weather can certainly play a role as well. It’s still July. In most growing locations, there’s still time for them to ripen before cold weather returns.

  2. Katie on

    Thank you for this article, it’s the first one I’ve found that has clearly explained the difference between these to issues and how to solve them…I now have an abundance of zucchini!

  3. Sara Brown on

    Thank you so much for very helpful advice. I have been adding lime and tomato fertilizer to my tomato plantings and I get a large crop late in the summer (Seattle area). Do you have an article on the planting stage for tomatoes?


  4. Garden Mentors on

    Sara, Glad to hear you’ve been having success. We’re not really sure what you mean by planting stage…what you can do is use our search on tomatoes to get a list of all of our articles. Maybe that will help you find the specific, free tomato advice you’re looking for. You can also sign up to be notified when enrollment opens in our teaching programs (some are for free!). That way you’ll be first in line to be notified when you can sign up! Good luck & keep having fun in your garden!

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