Blackheart is a physiological reaction of celery associated with poor calcium assimilation that occurs in most celery growing regions and is closely linked to growing conditions. Significant losses have been reported in Florida, California, Texas, Utah and Wisconsin. If conditions favorable for the development of blackheart persist the entire crown may be destroyed in a few days. In minor cases, the plants may recover or seem to recover, although symptoms can return. Symptom development is much more severe as plants approach maturity. The appearance of symptoms is closely linked to fluctuating water levels and available calcium. Environmental conditions that favor rapid growth such as heavy rain or irrigation subsequent to drought favor symptom development. High nitrogen, potassium, and sodium levels may also play a role. Certain celery cultivars are more susceptible to blackheart. Blackheart is prevented by ensuring steady plant growth, avoiding wide fluctuations in moisture and nutrients. Drench applications of soluble calcium can lessen or prevent the development of blackheart. Plant celery cultivars that are not prone to the syndrome. Drip irrigation which provides more even moisture levels can help reduce risk.