NPK Fertilizer for Cucumbers

[Izhar]

NPK 20:20:20 = 1 teaspoon in 2 litre water twice weekly
Sulfate of Potash = 1 teaspoon in 4 litre water once weely

[Alam64]

My tomato plants are just six inch with no growth last few weeks. Should i use the above solution. Since npk is chemical and tomatoes are edible, is it ok to use one tea spoon. I was using half

[muhammadimran7]

cover them at night and keep them warm don,t fertilize now