by Mark Burger
Tomato phosphorous deficiency – help!
5:09 pm in Nutrients, Nutrition, Plants, questions by Mark Burger
I started growing three tomato plants in my windowfarm using maxsea 16-16-16 plant food and started to notice that a portion of the stem is purple and the underside of the first two leaves are purple. The new leaves on the top are perfectly green. I read that this is evidence of a phosphorous deficiency. I was a little conservative with the amount of plant food I was adding in the beginning but I’ve recently been using a 1 teaspoon/gallon of maxsea 16-16-16 in a purified water solution. Is it wise to add a phosphorous supplement solution to my reservoir?! I also have my pump watering non-stop.
Just add some and see what happens. If it is indeed a phosphorous deficiency. It won’t hurt your plants to try.
I’m going to try phosphoric acid, that way I will lower the pH and add more phosphorous to my system. I’ll kill two birds with one stone!
Granted that hydroponic growing is not the same as chucking a plant into a nice raised bed of compost (which is why I’m here reading about it, having been solely a dirt-gardener) . . . I think your problem may be too much phosphorus. Normal soil/compost, and therefore fertilizer, should have an N-P-K (nitrogen-phosphorus-potassium) ratio of about 3-1-2 (6-2-4, 10-3-7, etc.) – anything with an even ratio is not balanced, in terms of standard gardening! Can you divide your plants into separate containers, for comparison of fertilizers?