Cannabis leaf Septoria is a fungal disease that affects cannabis plants, It often shows at early stage of bloom. It is treatable and tends not to affect the buds bit does affect plants health obviosly. It starts as yellow brown spots before spreading rapidly, yellowing the cannabis leaves before they eventually turn brown and die.
Calcium deficiency is sometimes confused with cannabis leaf Septoria, with certain similarities in the leaf appearance. We explain this later in article.
The septoria spots are small yellow/brown at the leafs. When left untreated, a hole may appear at the spot as the plant cells completely die. Cannabis leaf Septoria often starts in early bloom, with spots ranging from around 1mm-5mm in diameter, often on lower leaves initially before spreading up the plant. When the Septoria spreads the leaves take on a yellow appearance. This turns brown as the leaves die. Septoria has the potential to create a great deal of stress for the plant, reducing growth and influence yields. The fungus thrives in warm, humid conditions. Unless infected leaves are removed the spots spread up the plant.
Calcium deficiency tends not to start with the small yellow/brown spots with the dark core. Calcium deficiency in cannabis causes a range of biochemical issues, including generally yellow leaves.
Calcium deficiency will often have this impact for your plants:
Loss of overall growth vigour, leaves may wilt. Calcium is used in many different ways inside your plant and substrate. It is vital for overall stress resistance and general health.
Nutrient uptake by the roots may be affected. Calcium around the root zone helps organic matter to decay to absorb. Overall nutrient absorption will be affected with Calcium deficiency, preventing other minerals from being absorbed! This can cause a series of deficiencies of other nutrients and minerals, and even the intake of water by your plants. This will reduce yields of the buds. Cannabis requires extra calcium, in addition to other minerals/nutrients, in mid bloom. Using LED lights requiere other amounts of calcium as well.
The leaf spots with Calcium deficiency are different in form and shape as caused by Septoria. Note that Septoria infections start on lower leaves first!
Cannabis requires Calcium, alongside a range of other important minerals and nutrients, in order to maintain healthy growth. An absence of Calcium can look confusingly like other deficiencies because the cannabis plant is unable to continue generate essential biological functions. The symptoms of Calcium deficiency are wide ranging and may include the following:
Reduced new top growth of your cannabis plant.
Growth slows on new blooms and new leaves may curl or show a strained/twisted appearance before dying. Young shoots may show purple or yellow discolouration.
Bud production is reduced, especially in severe cases. New grown buds are small, deformed and dont reach full potential. Large, pale brown spots may form on leaves with Calcium deficiency. These don’t look the same as Septoria. With Calcium deficiency the leaf edges are affected and turn brown. Calcium deficiency leads to yellowing of the leaves and spreads showing it. Branches may be weak and easily broken.
Calcium is mostly available in well-prepared soil blends and can also be found in water that is used. If not you can add it yourself. Be aware of dosage, especially in combination with magnesium, look for the right rate in this! Calcium deficiency is more often seen in hydroponic grows as in grows on healthy soil, where the grower is fully responsible for ensuring that all minerals are present in the added nutrients. Even a small mistake during the creation of the hydroponics nutrients could lead to nutrient deficiencies or overdoses.
What to do when septoria is detected?
1.Remove infected leaves
If you have caught the Septoria early simply remove the affected leaves. The infected leaves carry the Septoria fungus, so they need to be removed from your grow area. It’s important to not strip every leaf off a plant in mid/late bloom.
2.Reduce moisture/ grow room humidity.
Fungal spores spread and thrive in warm, humid conditions. By reducing humidity, it de-optimises the conditions that fungus thrives in. Bring down temperature and humidity is a great way to make conditions as unfriendly as possible for Septoria. Spraying on leafs is not done if leaf Septoria is suspected - the regular damping of leaves with a spray increases Septoria to spread.
3.Improve air circulation.
Still, stagnant air (corners) in your grow room/greenhouse provide the ideal conditions for fungal spores to thrive.
5.Consider a top-dressing of mulch.
Some growers use mulch to protect between the soil and the plants. This to create a layer above the soil which makes it tougher for any Septoria or other fungus spores in the ground to spread onto the plant.