That looks more like birds are pecking the fruit or some other animal is nibbling them. When this sort of damage appears, it usually is an indicator that there's poor water availability for the wildlife so they are attacking your tomatoes to get water. To some extent, you can stop this damage by putting a bird bath or flat, shallow pans of water in the garden near the tomato plants to give the birds, squirrels and other wild things something to drink

You also can pick the tomatoes as soon as they develop the first flush of color, what is commonly referred to as the breaker stage. I harvest all my tomatoes at breaker stage and let them finish ripening up indoors on the kitchen counter precisely to get them indoors before birds, squirrels, turtles, caterpillars, stink bugs, etc. can ruin them. I'l link a USDA chart below that shows the breaker stage. One interesting thing I have learned is that tomatoes picked at the breaker stage ripen more quickly indoors than outdoors. Also, just in case you are worried about picking them early affecting their flavor---it doesn't. They still taste great.

Usually if tomato fruit are cracking or splitting from excessive moisture, you will see either radial cracking or concentric cracking first, or even weather checking (little zippered lines on the fruit), and when the fruit cracks it is an actual crack in the skin. This occurs because excess water can make the interior of the fruit enlarge more quickly than the skin can expand. If you want to see photos of the radial or concentric cracking, or weather checking, you can google those words along with the words tomato and either image or photo and Google should pull up plenty of photos.

It also is possible that your fruit started as a small crack and then the wildlife took advantage of the crack to peck away at the fruit to get to the water, but I think all you have is plain old wildlife damage.

If you click on the chart below, it will show you the breaker stage. Usually, as long as I harvest fruit at the breaking stage, or even the later turning stage, there won't be any wildlife damage yet. If I wait until it gets to the "pink" stage, I often find the birds or turtles or grasshoppers already have started feasting on the tomatoes. Often this sort of wildlife damage doesn't become a problem until or unless the weather is very hot and very dry, so I usually don't see it until July or sometimes, if July is cool and wet, until August. This year I started finding damage the last week in June.

Hope this helps,

Dawn

Here is a link that might be useful:

I forgot to answer your questions about watering. You cannot water by a formula because how much the plants need depends on what size plant you have, the existing moisture level (or lack of such) in your soil, the size of the plants and how much fruit they're carrying, etc. I wish we could just say "water once a week for 45 minutes" but it is more complicated than that and there is no "one size fits all" answer.

I grow about 100-120 plants per season and only do the most minimum watering necessary to keep the soil evenly moist because too much water ruins the flavor of the tomato. Tomato plants can tolerate a lot of rainfall or irrigation when they are younger and the plants aren't bearing yet or the fruit are small. However, excessive water as the fruit enlarges and ripens can totally ruin the flavor.

How much water your plants need at any given time of the growing season will vary, depending on your soil, how hot the weather is, how well you soil drains or how well it holds water, etc. You should aim to keep the soil evenly moist (not heavily soaked or waterlogged) several inches below the soil surface at all times. If you let the plants swing back and forth between being very wet and very dry, that sort of variance in moisture levels can lead to Blossom End Rot by interfering in the way the plants' vascular system transports water and nutrients. So, just aim for evenly moist soil and all should be well.

You say you aren't having much luck, but I think you're doing great. Look at the fruit---it is there, right? So you know that you have grown the plants well enough to produce fruit. Now, all you have to do is to continue what you've been doing while taking additional steps to keep the birds or other wild creatures from pecking at or taking bites out of your fruit.

If for some reason you do not wish to or cannot pick the fruit at the breaker stage, you could try covering your plants with bird netting, but smart birds (and squirrels, possums, coons and turtles) often figure out ways to get underneath or through or around the bird netting.

Thanks for you response. We are starting to pick our tomatoes sooner. Might invest in some bird netting. We have TONS of barn swallows around our house. They could definitely be getting into the tomatoes!

You're welcome.

An old trick to fool the birds is to hang hard, red Christmas balls (I used to say to use the glass ones that shatter easily, but now most are plastic anyhow) on your tomato plants early in the season. Birds will peck at them and learn that your "tomatoes" are hard as a rock and have no moisture, and they'll leave your real fruit around when it develops. This works in all but the driest of years.

We have tons of barn swallows too. I see them checking our window screens daily for bugs, but they never seem to come into the garden...or, at least, they don't do it when I'm outside.

I know bird netting can be handy, but I tend to find snakes or large birds hung up in it, so I don't use it in the garden. I will use it to keep birds off the fruit trees when fruit is ripening.

If you don't have too many to protect, you can snap a plastic clam shell container (like strawberries come in) over the fruit. Of course, none of MY tomatoes have been conveniently located for such protection, so I really don't know if it works. I've been picking like Dawn, too. I've got what I think are cut worms, they put a circular hole in the fruit. I found some kind of tiny worm/cat rolled up in some leaves today, so everybody got a bt shower. Enough is enough. Dawn I read to plant red cayennes in with tomatoes so the birds would think they were all hot. Trouble was, the cayennes didn't ripen till after the tomatoes. Maybe it works in other climates. Sure had a lot of hot peppers last year though.