9 Symptoms of Nutrient Deficiencies in Cannabis Plants & How To Identify Them.
Understanding the signs of nutrient deficiency in cannabis plants is vital information growers need to understand in great detail in order to improve crop yield.
Are your cannabis plants growing as well as they should? Are they healthy? Do they appear to have a nutrient deficiency? Not sure?
It’s essential to know the signs to monitor.
The challenge with growing cannabis is that different nutrient deficiencies have different symptoms and there isn’t one telltale sign to look for. Some deficiencies appear in the form of spots while others are burned tips or varying forms of discolouration. How you treat these deficiencies will largely depend on the signs that appear on the plant.
Below we’ll outline the most 9 common signs / symptoms of nutrient deficiency in cannabis plants and answer common questions we hear from our customers from California to Maine.
What are the symptoms of nutrient deficiency in plants? 9 nutrients to monitor:
The symptoms of cannabis nutrient deficiencies depend on the nutrient. Here’s a list of the signs of deficiency based on the nutrient type:
- Nitrogen deficiency: Plants are shorter, smaller leaves, yellowing that moves upward, lower leaves turn yellow, and premature flowering.
- Calcium deficiency: Smaller plant with slow flowering, random yellow and brown spots, lower leaves curl.
- Phosphorus deficiency: Slow vertical growth, leaves are blueish-green, copper-coloured dead blotches on lower leaves, some leaves develop purple colour and curl, wither, and fall off.
- Magnesium deficiency: The plant appears unhealthy, older leaves dry up, and yellow and brown spots on the leaves.
- Potassium deficiency: Mature leaves are pale, leaf tips are rust colour and burn, minimal flowering, small and weak stems.
- Sulphur deficiency: Weak bud formation, new leaves are lime green, purple streaks may appear on stems, and leaf tips can burn.
- Iron deficiency: Slow growth and smaller harvest, young leaves develop interveinal chlorosis, leaves may drop.
- Manganese deficiency: Young leaves develop interveinal chlorosis, dead spots appear, and margins stay dark around interveinal chlorosis.
- Zinc deficiency: Leaf tips burn and appear discoloured, with the growth of shoots that are bunched up, and wrinkled leaves.
Identifying the common symptoms of cannabis plant deficiencies can be difficult. If you’d like a more visual reference to what the various nutrient deficiencies look like in cannabis plants, download our Cannabis Fertilizer Growers Handbook and learn how to get 5X more buds with 80% less fertilizer.
3 Common Questions About Marijuana Nutrient Deficiency in Plants
Here are some other common questions regarding the signs of nutrient deficiency in Cannabis plants:
1. How do I identify nutrient deficiencies in cannabis plants?
There are a number of ways you can identify deficiencies in your cannabis plants. Visual signs that your plant is not healthy is a first option. Plants can also appear healthy but have slight deficiencies. Testing the irrigation water can ensure you are feeding the plant properly. Leaf tissue samples will give further insight into how well the plants are taking up the nutrients in the irrigation system.
2. When do nutrient deficiencies appear in Cannabis plants?
It depends on the nutrient. A study of Cannabis Nutrient Disorders from North Carolina State University’s Department of Horticulture found that symptoms began to appear on the cannabis plants 6-7 weeks after Nitrogen, Phosphorus, Calcium, Magnesium and Manganese nutrients were withdrawn. Whereas deficiencies of Potassium and Zinc appeared later in the growth: after 9 weeks.
3. What will happen to a cannabis plant having a nutrient deficiency?
A nutrient deficiency can have a significant effect on flower yield. For example, the North Carolina study found a Nitrogen deficiency produced 50% less crop biomass compared to the control plants. Potassium, a 27% decrease in biomass. That’s a huge difference to commercial cannabis growers who want bigger buds and an optimal crop yield it order to be financially successful.
In severe cases, the cannabis plant could die. The good news is, if the plant has minimal nutrient deficiencies, it can recover if you catch it quickly and take corrective action in order to optimize yield and produce a successful crop.
For more cannabis fertilizer tips, check out these blog posts:
- 5 Tips on Tank Mixing Water-Soluble Fertilizers
- Why Are My Cannabis Seedlings Growing So Slow?
- How To Use Plant-Prod Cannabis Fertilizers With A Two-Part A&B Nutrient System
Plant-Prod is a manufacturer of 100% water-soluble cannabis fertilizers made from the highest technical-grade raw materials in the world. For commercial cannabis growers wanting to increase yield and reduce costs, the purity and consistency of Plant-Prod MJ fertilizers means there are no fillers left in the bottom of your tank or clogging your lines saving you the time and money to clean them out. And your plants get 100% of what you paid for and you get bigger, denser buds and faster growth on a more consistent basis.
The choice of growers from California to Maine for over 70 years, we formulate everything from chelated iron, to calcium nitrate and zinc fertilizer in order to help you get bigger buds for your buck. Click here to find a Plant-Prod cannabis fertilizer supplier near you.