Deficiencies Due to Excess Nutrients
Deficiencies due to excess nutrients is a lot more common than you would think; many people believe that by giving their cannabis plants more fertilizers they’ll solve anything, and if your plants are showing potassium deficiencies then the best thing is to give them potassium. This isn’t necessarily true, as you could have easily over-fertilized your plants with nitrogen which annuls the absorption of potassium.
Deficiencies don’t always mean that your plant is lacking that specific nutrient in the soil – it might be that since last measuring the pH, more and more nutrient has accumulated in the soil and this could provoke blockage, as well as having too much of one nutrient can easily block the absorption of another.
In this article we’re going to go through a list of nutrients that are generally used in growing and can cause deficiencies when used in excess.
This is a nutrient that tends to be given to cannabis plants during their growth phase. Nitrogen is the mineral that your plant uses the most, but excess nitrogen can provoke various deficiencies in the future such as potassium and calcium deficiencies. An excess of growth fertilizer will cause your plants to begin flowering later, and you’ll see signs of potassium deficiencies or yellowing leaves due to an obvious calcium deficiency – so take care to not use too much growth fertilizer if you want your plants to flower healthily!
Potassium is generally found in flowering fertilizers or additives used during the bud fattening phase. An excess of this nutrient can cause nitrogen, calcium or magnesium deficiencies. It doesn’t matter how many micro-nutrients you use to try and solve the issue, if your plants have too much potassium they won’t be able to absorb what you need to give them – one of the best things you can do in this case is to wash the roots out completely to remove any excess, then give your plants the nutrients they need to get better.
Phosphorus is the nutrient your plant needs most once it begins the bud fattening stage. To grow large buds, plants need big doses of this mineral, but if you use it too soon it can cause excess and accumulate in the roots. If this happens, your plants won’t be able to absorb zinc, iron and copper. If this happens you’ll need to flush the roots before giving it anything else and make sure that it’s still not too early to use fattening products.
Calcium is essential for your plants, although they don’t need too much of it, and most of it is given in flowering fertilizers and from tap water. When giving your plants extra calcium you’ll need to be careful, as too much of it can disrupt the absorption of nutrients such as boron, magnesium and even phosphorus – this could be fatal for your plants if it happens mid-fattening period. If you notice a deficiency of any of the previously mentioned nutrients during this period then you’ll need to make sure you didn’t use too much calcium before starting to add extra stuff, as you might make the situation even worse.
Many different fertilizers give your plants calcium, and during the flowering period it’s usually given so that your plants don’t show any sort of deficiencies; an excess of this nutrient can cause both potassium and calcium to not be absorbed. If you use magnesium during the flowering period you’ll need to use it with osmosis water and a nice and controlled EC level – do not use in soil unless you’re trying to fix an obvious deficiency.
This mineral is generally used in keeping mother plants healthy, as they need high levels of this nutrient in order to keep up with the stress of constant cloning. An excess of this mineral can stop your plants from absorbing manganese, and your plants will most likely stop growing and the leaves will be quite ruined. If you use iron in your irrigation water, make sure that you don’t use it more than once every two weeks.
Sodium can easily be found in tap water, and if you water your plants for a long time with this kind of water you might end up with certain deficiencies due to excess sodium. That white lime-like substance that accumulates in your flowerpots is sodium, and an excess of it can cause deficiencies of potassium, calcium and magnesium. Using tap water can cause a whole lot of deficiencies, so it’s best to use osmosis water for your cannabis plants if you don’t want any nasty surprises.
Many different fungicides and insecticides use sulfur in their ingredients as it changes the pH of your plants surface area and gets rid of all kinds of fungi and aphid. Using these kinds of products ensures that you have no fungi or infestation issues, but using it too much can cause deficiencies such as molybdenum, which will cause your plants to begin going yellow – if you plan on using this product, take care to not use too much; once every 20 days before flowering to prevent issues and once every 10 days to cure your plants should be enough.
Before trying to solve a deficiency with more products, make sure that you’re certain that you haven’t gone overboard with any of these minerals in your grow. If you have, simply wash out the roots before solving the deficiency – there are various products on the market that can help you out with flushing the roots, such as Canna Flush by Canna.
Author: Javier Chinesta
Translation: Ciara Murphy