Prevent Blossom-End Rot with Bone Meal

Have you ever spent 3 months growing your lovely tomato plant, only to end up with tomatoes that start to rot before they’re even ripe? What about having your eggplant lose its blossoms before they get a chance to turn into fruit? Prevent blossom-end rot with bone meal.

Prevent Blossom-End Rot with Bone Meal Blossom-end rot (when the bottom of your fruit rots) is often caused by a calcium deficiency. And lack of blossoms can be caused by a phosphorus deficiency.

What’s an organic way to solve this problem? Bone meal.

Bone meal is an organic, slow-release fertilizer that can add calcium and phosphorus to your soil. Because bone meal takes time to break down, slowly releasing nutrients into the soil, it provides a steady dose to your plants over time. This is unlike blood meal, which can burn your plants if you add too much.

blossom-end rot on tomato

Most vegetable plants will benefit from bone meal applications, but it is especially beneficial for root crops (like carrots and onions), as well as flowering crops (like tomatoes, peppers, and eggplant). Bone meal is also beneficial for any other flowering plants that you may have in your yard or garden.

Bone meal provides nutrients to your plants to help with root growth, flower growth, photosynthesis, and of course, as the title mentions, preventing blossom-end rot.

bone meal to prevent blossom-end rot

Calcium Benefits from Bone Meal

Calcium is a secondary nutrient that plants need for growth. Plants use calcium to produce cell walls, which helps to strengthen stems and new shoots. It also helps with root ends and prevents blossom-end rot.

When plants are deficient it will show in the leaves and fruit of the plant. For leaves, it will show in the younger leaves first. The leaves will look deformed, with tips dying, and eventually, leaf production will stop altogether. Roots will also be stunted, but unless you’re rooting around and digging up your plants you won’t be able to see that. And if you are… your plants might have a bigger problem than calcium deficiencies.

Worst of all, calcium-deficient fruit can develop blossom-end rot. This causes the blossom end of the fruit to become dark and eventually rotten. This is especially common in vegetables such as tomatoes, eggplant, and peppers.

Another organic and natural source of calcium is limestone. Just keep in mind that adding too much calcium to your soil can raise pH levels, making the soil more alkaline.

Phosphorous Benefits from Bone Meal

Phosphorous (P) is one of the three most important plant nutrients, also known as macronutrients (the other two being Nitrogen (N) and Potassium (K). Phosphorus is needed for root growth, flower growth, and photosynthesis.

Phosphorus is especially important when plants are developing roots, so it’s good to add some when plants are just starting out or when you’re transplanting them into your garden.

When plants are deficient in phosphorus it can produce stunted growth, spindly stems, underdeveloped flowers, or no flowers at all. Leave can also have dark veins while the rest of the leaf fades.

Other organic or natural sources of phosphorus include rock phosphate and manure.

Adding Bone Meal

Before adding bone meal to your soil, you’ll want to check your pH levels, which you can learn more about with the post Testing Your Soil pH Levels. Bone meal won’t be absorbed by plants if the soil pH level is above 7. Checking your soil’s pH level is easy with a pH meter. They’re fairly cheap and easy to use as a guide. If your soils pH level is above 7, and your plant does better with it lower (as most vegetables do), you can add blood meal to lower it. And then add your bone meal.

bone mealYou can add one tablespoon per square foot or pot that you have. In addition to adding this to fruiting vegetables, it’s also good to add it to any flowers you have growing. There are many different bone meal products out there, and instructions should be labeled on the package for how much you should apply.

If you’re transplanting your flowers or vegetables, it’s good to add the bone meal in the hole before you plant as an initial soil prep. It will encourage new roots to form.

using bone meal in the gardenWhen adding bone meal to your soil you’ll want to make sure you mix it into your soil a bit in the top couple inches of soil so that animals can’t get to it. If eaten in large amounts bone meal can upset dogs, raccoons, and other animals. It has a fine powder consistency that can be easily mixed into your garden.

spreading bone meal in the gardenBone meal can feed plants for up to four months, but I typically add bone meal to my flowering plants every other month.

healthy tomatoes from bone mealDo you Prevent Blossom-End Rot with Bone Meal? If you use bone meal or anything else for blossom-end rot, we’d love to hear it! Comment below.

Happy Gardening! 🙂

Prevent Blossom-End Rot with Bone Meal


  1. Thank you for sharing. I found this info very informative & helpful. I did have this problem last year so I will be picking up some bone meal !!!

  2. Been battling this problem consistently year-after-year! Just picked up on this tip – jury’s still out but this Jersey Boy waits and prays!

  3. This is very informative. We live in South Texas.. we did soil samples and sent them into our County Co-op for analysis. We’ve followed guidelines closely as how to tend to our vegetable garden, as well as our flowering plants, shrubs, and trees. It’s made a HUGE difference in our vegetable yield, and after about giving up that our Mexican Flame was ever going to bloom, we have sooo many buds. It doesn’t get into the 40s, or maybe the 30s, until late December or January, so we have lots of “room to play”! Thanks again for the info! Happy gardening Y’all!!

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