you can also sprinkle 2-3 tablespoons of the granular Epsom Salts into each planting hole and mix with the soil when you plant the little buggers. I also plant them up to their leaves burying the stem so they'll form a stronger root system to support the vines. Yes, you're right. They need magnesium and drop their blossoms if they don't have enough. And too much nitrogen will make beautiful leaves but no fruit. Also, temperatures over
84o F will prevent the setting of fruit, unless you have specific heat tolerant varieties... madgardener