brown spots on leaves

[parqua]

hi all im looking for some help with 1 plant which has developed these brown spots on the upper leaves. i have checked them again this morning and the leaves lower down the plant loomk to be losing there colour can anybody help withh what this is.

 

[Cannaficiando]

Hey parqua...looks like calcium deficiency. Could be a pH problem; have you tested the pH of the runoff (the water seepage from the bottom of the pot after watering)?

You could try foliar feeding (spraying the plant with a dolomite lime solution - one teaspoon per quart of water). This should help in the short term, but if your pH is out of whack, that's what needs to be addressed.

 

[Muddy]

Looks like possible phorphorus and magnesium deficiencies. When both happen at the same time it's a good bet your soil pH is off. We'll need more information to know for sure. What are you feeding and how often? What is the pH of your nutrient feeds and the pH of your run off water? What kind of soil are you using?

 

[parqua]

I'm feeding them canna flores at half the recommended strength every other watering. The ph of my nutes is 6.1 and the runoff is slightly higher at 6.3. The soil is canna promix.

 

[Muddy]

pH is fine. Is that the Terra Professional Plus soil? Also, how old is the plant? Post a picture of the whole plant so we can see how the rest of it looks.