Is this plant showing a sulfur deficiency?

I am a first time grower. The “newer” leaves appear to have interveinal chlorosis. Some of the leaves have (dark) brown flecks (necrosis). These symptoms are appearing in the middle and upper part of the plant. I am thinking there is a Sulfur deficiency? I am growing indoors using Nature’s Living Soil. I am hoping to get some advice on how best to diagnose/thoughts about it being a sulfur deficiency. Thank you.

Calcium and Magnesium. You can Google “cannabis deficiency” and you’ll get all sorts of images/posters showing how various nute deficiencies look.

But that can also get you in trouble. Often the problem is something else which is causing the plant to not be able to uptake these nutes, not that they are absent from the soil.

An issue with your soil’s pH can also cause this problem. If you have been using molasses, that will affect your soil’s pH. 6.5 is your target for cannabis and most fruits and vegetables.

You can pick up some soil test strips for like $10. I’d want to check that before I start adding more fertilizer.

1 Like

@CurrDogg420 Thank you. The pH is 6.7…so that seems reasonable. I recently added a TBSP of dolomite powder but it seems the brown spots are on more leaves.

soil feeding will take a minimum of a week to 10 days to hit the plant. You have to check the NEW GROWTH…

1 Like

@solarslurpie looks like a root issue, overwatering? Fungal?, looks like you have intrevenal chlorosis, some brown mottling, with potential nitrogen toxicity.(organic fungicide on top of soil, a bit of iron and manganese,slight bit of kelp, chill on the “N” for now flush with plain h20, let it dry almost completely.,:us_outlying_islands::sunglasses:

1 Like

just a note - Blackstrap molasses contains both calcium and magnesium and makes a good SPRAY
Leaves absorb within 2 days as where soil requires a min of a week to uptake nutes