Canna - N 17% Nitrogen

A single-element nitrogen fertiliser with 17% nitrogen, for correcting nitrogen deficiencies and supporting vegetative growth. 1 to 2 ml per litre.

The bottle to be most careful with

CANNA print a warning on this pack that appears on most of their other mono bottles too, but carries the most weight here: a good fertiliser contains all elements in the right proportion, dose carefully, and an overdose can harm the plant.

With nitrogen that is not a formality, for two reasons. The first is that nitrogen is the element a plant responds to most visibly: darker leaf, faster stretch, a crop that looks prosperous. That is exactly the kind of feedback that encourages people to give more.

The second is that too much nitrogen is not neutral. It pushes the plant towards leaf rather than flower, it makes tissue softer and therefore more susceptible to fungus and insects, and it crowds out the uptake of potassium and calcium. A crop with a nitrogen surplus looks good for weeks and then disappoints.

Hence the practical rule: use a standalone nitrogen bottle to repair a deficiency you have identified, not to accelerate growth that is already going well.

Why there is no oxide form on this label

The rest of this range states an oxide: P2O5, K2O, CaO, MgO. This bottle simply says 17% N, and that is not an inconsistency.

Phosphorus, potassium, calcium and magnesium are traditionally declared as oxides in the fertiliser world, even though the plant has no use for that form. Nitrogen has no such convention: it is always declared as the element, because there is no stable oxide form you would put on a label.

Which means 17% here reads directly as 17% nitrogen, while with the other bottles you have to convert before you can compare with another brand.

Where a deficiency shows

Nitrogen is relocated within the plant, like magnesium. Running short, the plant pulls it from old leaf and sends it to the growing points.

So the picture is yellowing that starts low down, but unlike magnesium the whole leaf discolours evenly rather than just between the veins. Lower leaves go pale green, then yellow, and drop while the top carries on growing.

In flowering some of that yellowing belongs there: the plant is deliberately winding nitrogen down and drawing reserves out of the leaf. Repairing that with a standalone nitrogen bottle works against your ripening.

Technical Specifications:

• Type: single-element mineral fertiliser, liquid
• Manufacturer: CANNA
• Content: 17% nitrogen (N), declared as the element
• Use: for identified nitrogen deficiencies and to support vegetative growth
• Dose: 1 to 2 ml per litre of tap water
• Substrate: soil, coco and all hydroponic systems
• Warning: an overdose can harm the plant, dose carefully
• Volume: 1 litre

Frequently asked questions

Why no oxide form here when the other bottles have one?
Because nitrogen is always declared as the element. There is no oxide form used on a fertiliser label, unlike phosphorus, potassium, calcium and magnesium.

What happens with too much nitrogen?
The plant makes leaf rather than flower, tissue gets softer and more prone to fungus and insects, and potassium and calcium uptake is crowded out.

My lower leaves are yellowing in flower, should I feed more?
Usually not. In flowering the plant deliberately winds nitrogen down and draws reserves from old leaf. Feeding then works against ripening.

How do I tell it from a magnesium deficiency?
With nitrogen the whole leaf discolours evenly; with magnesium it yellows between the veins while the veins stay green.

Can I spray it on the leaf?
CANNA only mention foliar application in this range for magnesium. Feed nitrogen through the water.