Posted on

calcium deficiency in cannabis

Calcium deficiency in cannabis

  • Inhibit nutrient uptake at the roots. Calcium aids in the decomposition of organic matter at the root zone, facilitating nutrient absorption.
  • Impede flower growth during peak florescence. Cannabis uses extra calcium in the middle of the flowering process. Depending on species, this can be from three to six weeks into flowering.
  • Cause nutrient lockout. Poor functioning roots means poor nutrient uptake. The plant may display several types of nutrient problems when this happens.
  • Cause plants to lose vitality and wilt. Calcium is essential for general plant health and stress resistance.

If your water is 150ppm (EC 0.3), then there is little risk of calcium deficiency. Using unmodified RO or distilled water can strip calcium from plants. Before making a nutrient solution, add two parts calcium to one part magnesium to the water until the ppm reading is at least 150-200 (EC 0.3-0.4).
Soil: Avoid calcium deficiency from the outset with good soil selection. Make your own soil or buy a commercial mix with plenty of calcium for the life of the plant. If on that rare occasion a calcium deficiency is identified, there are a number of ways to rectify the problem:

  1. Make a mixture of one teaspoon hydrated lime to four litres of water and water in.
  2. Use a commercial calcium booster or liquid lime.
  • New growth at the top of the plant is primarily affected.
  • Young growth slows, new leaves curl. Fresh growth is twisted and dies off quickly. Young shoots are purple or yellow.
  • The root system is compromised so fewer nutrients will be absorbed. Overall growth slows and plants lose their lustre.
  • Flower growth severely affected, especially at peak florescence. Young calyces are crinkled, distorted and don’t fill out.
  • Large, light brown necrotic spots form on leaves. Leaf edges mottle and turn brown. Leaves become yellow as the problem advances.
  • Branches are weak and break easily. Stalks may become hollow and rot inside.
  • Plants do not respond well to heat.
  • Roots become brown and are susceptible to slimy root rot and other pathogens.

Calcium acts in concert with other important compounds to ensure overall plant health and vitality. A lack of calcium can mimic other deficiencies since the plant’s ability to maintain essential biological functions is compromised.
The following represent symptoms of a calcium deficiency:
There is little chance of a calcium deficiency growing outdoors in pots or growbags. Contemporary soil mixes usually have a complete spectrum of vital nutrients for the life of the plant. Organic growers will have no-till winter companion plants rehabilitating the soil for the new season.

Growing outdoors in soil generally allows for a greater margin of error with many nutrient problems. Unmodified acidic soils like those found in pinewoods can leach calcium, but proper attention can prevent calcium issues. Modify the soil with garden lime, dolomite, powdered bones, crushed eggshells or fish meal. Good quality compost is always a must.

Calcium deficiency in cannabis can slow growth and inhibit flowering. Find out how to identify and fix calcium deficiencies for indoor and outdoor grows.

Calcium deficiency in cannabis

Thanks for reading! You can find more information on anything related to growing in our cannabis grow guides. All of our guides are written by experienced growers, and members of our cannabis growers forum. If you have any questions, sign up. It is free, and we are always happy to help!

Time will be needed for the microbes in the medium to break the nutrients down and make them available to the plant. It is better to try and offer the plant more calcium as they get older.
Symptoms of a calcium deficiency will first show with orange/ brown spots appearing on the leaf margins. This will be seen on the bottom half of the plant first, but will move around in extreme cases. Leaves will also twist and curl at the bottom of the plant.

When growing cannabis in hydroponic setups like DWC or coco, you are more likely to experience a calcium deficiency. This is because calcium will be best absorbed by your plant when the medium is at 6.0 – 6.2 ph. The optimum pH used in hydroponics, is 5.8, so sometimes, calcium can be slightly out of range.
A cannabis plant needs a wide range of nutrients to grow strong, and healthily. Calcium deficiency in a cannabis plant will affect the uptake of many different nutrients. Calcium is used for many things in the growth of a cannabis plant. If your plants have a calcium deficiency, their growth can seriously be affected.
Stems will become weak and hollow. And they will snap easily. Your plant will also be more susceptible to heat stress, as calcium helps open and close the pores on the leaves (Stomata). If there is a lack of it, the plant can not breathe/sweat. This will affect the whole nutrient uptake of the plant.
Knowing this, you can help prepare for your next grow, and supplement a little more calcium, just as you flip the light to flower cycle.
The uptake of nutrients in a cannabis plant can be a complex process. Each nutrient will help another, and together they can grow a happy, healthy cannabis plant. If even one is off balance, the rest can soon start to follow. Keep the pH steady, and keep the EC low. Follow what your plant is telling you. If you need any help diagnosing a cannabis plant problem you can ask for help in our Plant doctors section of the forum.

Adding a cal/mag nutrient from one of your favorite nutrient lines will also improve the calcium content of your medium. But use it lightly, it is easy to overdose the plant and cause calcium excess.

Calcium deficiency in a cannabis plant will affect the uptake of nutrients. Diagnose a cannabis plant problem, and get help in our cannabis growers forum