Joanne S. – California
I have Dr. Earth Organic 5 tomato, vegetable and herb fertilizer from years past and the top says 5-7-3. What do those numbers stand for? Also, I have one beefsteak tomatoe plant in a pot on my balcony and some of the leaves are turning yellow. Does that mean it needs nitrogen? Also how much do I use for one plant?
The numbers stand for NPK (N) Nitrogen (P)Phosphorus (K)Potassium in that order. As far as your tomato plant the yellowing, it could be over watering. Play around with your watering habits to see if it stops. If it still yellow after adjusting water habits then, yes, it could be a lack of iron. Our tomato, vegetable & herb fertilizer will give your plant a balance diet and should correct that. I suggest getting a hold of a newer batch of our Fertilizer, Organic 5 / 5-7-3 is very old and I suggest our most current version Home Grown Tomato, Vegetable & Herb Fertilizer.