Should I use epsom salt foliage spray on giant sunflowers?

Question

I'm currently growing some giant sunflowers. I really want them to be as big as possible. I'm wondering how good it would be to spray them twice a week with a epsom salt, gypsum and / or saltpeter spray?

Answer 1

You're unlikely to notice any big difference from this treatment. It would be more useful as a soil treatment. For consistent giant sunflowers, soil and light are the most important things to get right.

That being said, foliar sprays aren't a bad idea, you just want to use something readily available for foliar uptake. It would be best to get a manufactured fertilizer designated for foliar spray application. Remember to spray the leaf undersides.

Answer 2

I use foliar sprays extensively. I have found there are certain garden varieties which do not do well when sprayed with Epsom salt. Among these are Sage, and most succulents. I suspect the Sage fuzzy leaf surface plays a roll but all the other Mints I grow tolerate Epsom salt.

Sunflower benefits mightily from my foliar sprays but I never use straight water/Epsom solutions. During the growing season I spray twice a week. Once with FPJ (Fermented Plant Juice) and Epsom salt in water. Once with Fish Emulsion and Epsom salt in water.

Sunflowers thrive on this regime with vigorous, wind proof stalks and massive heads. I spray after the sun sets or before it rises. If you prefer natural solutions this method is worthy of effort.

I use one half a teaspoon of Epsom salt in 1-1/2 gallons of water. Curiously vines especially benefit from this treatment. The entire Nightshade family could take double doses.

These Datura were sprayed twice a week as per above.