Tomato rot

dont forget to mulch the top layer of the pot.

it will help reduce some evaporation.

On sunny days this time of year, with a good sized plant growing, I must water my tomato pots each day.

a good way to tell if it needs water is to tip the pot and check the weight. Do it when you know its well watered so you have something to compare.

The problem is called Blossom End Rot. Right at the time of fruitset, the plant needs a fairly steady source of calcium. Rapid fluctuations in moisture, like the huge rains we got this spring, a rapid change to hot weather, or letting the container dry out too much, can cause a temporary calcium deficiency, and those fruits that were setting right at that time end up with blossom end rot. Over fertilization can increase the likelihood of rot.

The good news is that the plant usually grows out of the condition, and your next sets of fruits will probably be just fine.

As to the question of when to water, the answer is always "When the plant needs it." The size of container, the weather, and potting medium all make a difference. Check the container daily and water thoroughly whenever it is drying out. Tomatoes need a lot of water when they are actively growing and ripening fruit, so expect to water daily (or more) when we get to the really hot part of our summer.

As to how much to fertilize, again, it depends on the size of the container and what you've chosen as a potting medium. In general, if you're using a typical soilless potting mix, this time of our season, once a week with your Miracle Gro is probably about right.

Here are a few fact sheets that should help.

Growing Cucumbers, Peppers, Squash And Tomatoes In Containers (Ohio)

Growing Tomatoes (K-State)

Container Gardening (K-State)

Meg - Johnson County Extension Master Gardener