Canna Flower Turning Brown. In severe cases the leaves will turn brown and yellow all over and the rust can kill the plant. Canna rust is a fungus that causes orange yellow and brown spots on the plant leaves and stems.
A gummy sap may bleed from diseased areas on stalks. If leaf rollers are present its best to remove the affected foliage and or spray with Neem oil or another kind of insecticide. There is the potential for the spadix to turn white again but it commonly starts to go brown.
I water every day.
Lastly the leaves may be turning brown signaling the natural end of the growing season. Make sure the plants are growing in moist but well-drained soils. 22092017 Actually more is not always better and over-saturating your cannabis plants with nutrients is a common way to end up with brown weed leaves. The condition is aggravated by overwatering overcrowding and poor aeration.