Will this test tell me what to add to the soil to help my citrus tree and other blooming plants bloom. My citrus tree blooms all turned black.

Yes, this soil kit can help you adjust your soil to achieve the pH of 6.5 – 7.0 that is required for citrus plants. Citrus needs soil containing nitrogen, phosphorous and potassium (NPK) for your plant to thrive. This kit contains tests for you to see where the pH, nitrogen, phosphorus and potash levels are in your soil. Just follow package instructions for testing and material to add and amounts to add based on your soil tests. And, sometimes, overwatering does cause fruit blooms to blacken. A soil moister meter can be purchase at Lowes and will determine the dryness or moistness in your soil. Test the soil moisture levels in the root zone. Your best bet is to monitor soil moisture regularly. Follow a consistent schedule, watering as infrequently as possible, but allowing water to soak through the root zone and out the drainage holes each time. And, make sure the pot sits above any salty drainage water, so it won't be reabsorbed and damage roots.