I'm actually disappointed at my searches for Calcium deficiency remedies as all I am finding is speculation, with no solutions! Â I do know this. Â Lime, eggshells, limestone, etc. won't work. Â My soil is high in Ca. Â The problem is it's not available to the plant in these forms. Â Bone meal is mostly this way too - but sometimes there are other forms of Ca in it that may be absorbed better. Â Epson salts have no Ca, but again as stated above may help make CA available or be transported, and you may have Mg issues too? Â Though some sites state that too much Mg can make Ca less available! Milk - not sure on the Ca part - probably not enough in it as a spray? Â But it's perfectly OK to spray on plants. Â I've used it for powdery mildew and it worked on some plants and did not on others, but no ill effects. Â I watered it down = about 1:4 milk to water. Â I don't have the perfect answer, even sites where speculation is not the main way of communication, there seems no great answers. Â I will try Calcium chloride (I have some bulk form for pickle making and brewing), and Epson salts and see. Â I'm not even sure the problem is Ca deficiency with my plants!