When growing marijuana, it’s important to pay attention to the nutrient needs of your plants. This can help you avoid nutrient deficiencies, which can lead to poor growth and even crop failure.
Nutrient deficiencies can affect any cannabis plant, so it’s important to know how to spot them and prevent them from occurring. Here are a few signs of a nutrient deficiency in your plant and how to treat it.
Nitrogen
Nutrient deficiencies can be a real problem for cannabis growers, but the good news is that they are easy to identify and prevent. All you have to do is look for some specific symptoms and figure out which nutrient your plant needs.
Nitrogen is one of the most important nutrients for cannabis growth. It plays a vital role in photosynthesis and the production of chlorophyll and amino acids.
The first sign of a nitrogen deficiency is yellowing leaves. If you notice a shortage of this nutrient, try to add extra to your feeding schedule. This will help your plants get back on track.
Another common symptom of a nitrogen deficiency is wilting and withering foliage. This isn’t something you should stress over, but it can indicate a lack of N and should be addressed quickly.
Phosphorus is another essential nutrient for cannabis. It helps your plants produce chlorophyll and adds structural strength to their roots and stems.
When a cannabis plant isn’t taking in enough phosphorus, it will have trouble producing the leaves it needs to get started. It will also have trouble building up the structural strength it needs to support its weight.
A phosphorus deficiency can cause the leaf tips of your cannabis plant to turn brown and curl in. Other plant parts will darken as well.
Boron is another nutrient that can slow down the growth of your plant. It’s rare for cannabis to experience this deficiency, but it can cause your leaves to go brown and fall off.
Potassium is another nutrient that can have a big impact on your cannabis plant. It has many functions, including increasing root growth and drought resistance, maintaining turgor, and helping plants translocate sugars and starch.
It can also increase the speed of flower development and boost yields.
Potassium deficiency usually happens during the flowering stage, so it’s a good idea to flush your soil and feed with potassium-rich fertilizers. If you don’t know where to start, ask a professional grower or your local horticultural supply store for advice.
Phosphorus
Phosphorus is a vital nutrient for cannabis plants throughout all stages of growth, from germination and root formation to growing and flowering. It helps the plant to stay healthy and vigorous, so identifying and correcting phosphorus deficiencies can have a significant impact on your harvest.
There are a number of different symptoms that can indicate a phosphorus deficiency in your marijuana plant. The first sign is the yellowing of the leaves, especially those that are closer to the base of your plant.
The leaves will begin to take on a dull green, blue or grey colour and may also develop purple or brown spots. These spots will appear mainly on the lower leaves, but they can also affect the stems of your plant as well.
These symptoms can be exacerbated by cold temperatures, compacted soils or overwatering. The best way to prevent this from happening is to check the pH levels of the roots before watering your plant.
If your pH levels are out of whack, you can easily fix the issue by flushing your system with pH adjusted water that contains phosphorus in addition to other nutrients. This will help restore the pH levels to the proper range and ensure that your plant can absorb the necessary amounts of phosphorus.
You can also use foliar feed sprays that contain a nitrogen-rich nutrient, such as seaweed or fish-based foliar feed sprays. These are particularly effective in reducing the risk of phosphorus deficiency.
Phosphorus is a mobile nutrient that moves through the plant system to reach areas where it is most needed. However, it can sometimes be hard to know whether your plant is suffering from a phosphorus deficiency or phosphorus toxicity.
The difference is that the latter can cause a massive nutrient lockout of other elements, such as calcium, copper, iron and magnesium, and zinc is one of the first to get locked out.
In addition to phosphorus, your cannabis plant is likely to be lacking in other important micro-nutrients like iron and copper. These micro-nutrients are essential for the proper uptake of phosphorus by the plant.
Potassium
Identifying and preventing nutrient deficiencies in cannabis plants is crucial, especially during the flowering stage. If a plant doesn’t get enough potassium, it may fail to develop buds, and the buds will be weak in flavour and aroma.
Luckily, the problem is easy to fix if you catch it early enough and act quickly. In most cases, you can simply add some potassium-rich nutrient feeds or even foliar fertilizers to your growing medium and watch for improvements in your crops’ health.
Signs of potassium deficiency include yellowing, burning, or crispy edges on older leaves. They also typically appear between leaf veins, and the areas that were affected will begin to die if left untreated.
Potassium is an essential nutrient for a number of processes in cannabis, including the creation of terpenes. It’s especially important for bud development during the flowering phase, as it helps your buds to develop and get bigger.
If your plant is suffering from a potassium deficiency, the first thing you should do is test its pH levels. If the soil is too acidic (pH 6.0-7.0), you can flush it with pH-balanced water to help it absorb potassium properly.
A good source of potassium for your cannabis plants is kelp. You can liquefy it for use as a foliar feed or topdress your grow medium with it. Another slow-release potassium source is greensand or granite dust.
Other than kelp, you can also use a range of other sources to give your plants the nutrients they need. For example, you can use a potassium sulfate (wiki), a potassium bicarbonate, or a potassium dihydrogen phosphate.
It’s also a good idea to add a calcium supplement to your cannabis-specific nutrient mix. This micronutrient is critical for developing strong, healthy cell walls in your plant.
In addition, it can help nitrogen and sugars move through your plant more easily. You should also ensure your grow room’s lighting is at the correct distance from your plant.
If your marijuana plant has a potassium deficiency, you’ll need to fix it right away. As with other nutrients, you can start by testing your water’s pH and then reducing the strength of your nutrient solution to half. You can also perform a soil flush with neutral-pH water to cleanse the medium and help your plant take up potassium again.
Boron
Cannabis plants require a balance of nitrogen, phosphorus and potassium (N-P-K) to grow. A deficiency of one of these three nutrients can lead to poor growth and, in severe cases, death.
If you see yellowing and discoloration on any of your cannabis plant’s leaves, it could be a sign of nutrient deficiency. It’s important to diagnose the problem correctly and resolve it quickly, so that your plant doesn’t lose more leaves due to lack of a vital nutrient.
Nitrogen is an essential nutrient that helps plants grow and produce a wide variety of products, from sugars to proteins. Deficiency of nitrogen can cause problems like brown spots and stunted growth in the plant, which can result in reduced yields.
Phosphorus is a mineral that plays a critical role in the creation of carbohydrates, chlorophyll and amino acids. Symptoms of a phosphorus deficiency can include dark spots and rusty leaf tips on older leaves.
It’s also possible for a plant to develop interveinal chlorosis, or yellowing on the youngest leaves. This can occur if the pH of the substrate is too high or if it’s difficult for your cannabis plant to absorb phosphorus from the soil or grow medium.
Fortunately, there are many ways to prevent phosphorus deficiencies from happening in the first place. These include avoiding excessive fertilizer applications, using water-soluble fertilizers, and providing your plant with plenty of sources of phosphorus through the grow cycle.
Calcium is an immobile micronutrient that works to fortify the cell walls of your marijuana plant. It is important for healthy root development and new leaves, as well as ensuring that the plant is able to take in Nitrogen and sugars properly.
If you notice signs of a calcium deficiency, such as dead spots, crinkling and small brown spots on your plants’ leaves, it is important to deal with the issue quickly. As with magnesium, you may need to use specialist Calcium and Magnesium rich nutrient solutions in order to restore your plants’ health.
Zinc is another nutrient that can cause yellowing and discoloration on cannabis leaves, but it’s not as common as a copper deficiency. As with calcium, you’ll want to address this issue as soon as you notice it in order to avoid losing more leaves and having the plant fail to flower.
