As your Cannabis plan ages you may notice that some leaves turn yellow and dry out. In general, this phenomenon starts with the first feeder leaves located at the base of the plant and gradually spreads upwards. If your plant looks vigorous and healthy at the top and the harvest time is approaching, then there is no reason to worry. In the terminal phase of flowering, your plants will tend to redirect their vital forces towards the terminations in order to accelerate the formation of resinous buds.
What can you do?
Let nature take its course! It is simply necessary to follow the natural ageing of the plant which does not wish any more to nourish its first leaves in order to concentrate its energy at flowering.
But if you can’t resist the urge to take action, give it a little help by proceeding to a meticulous defoliation. With small scissors delicately remove all the dry and crumbly leaves located at the bottom of the plant, which will thin out the foliage and will give again to him the cheerful aspect of a vigorous and promising plant.
Nutrient and pH deficiency problem
Nutrient deficiency is the most common reason why your plants will have trouble keeping their leaves happy and healthy. But beware, a nutrient deficiency can hide another problem: a bad pH.
This is simply because Cannabis has a small pH range in which the plant is able to absorb nutrients. So it’s quite possible that the nutrient value of your watering solution is correct but the pH is not, resulting in a blockage of nutrient absorption.
What can you do?
Whenever you see that something is wrong with your plant, always check the pH level near the roots before doing anything else. The pH should generally be between 6 and 7, but it should be a little more acidic in hydroponics, between 5.5 and 6.5. Depending on your result, you will need to balance its level with pH adjusting products. If your plant still shows signs of nutrient deficiencies, it will be necessary to readjust your irrigation solution to your new growing medium. But that doesn’t mean that more is better! It is important not to overload your plants with too high nutrient levels as this only makes things worse.
As with nutrients, lack or excessive water intake can be harmful to your Cannabis plants. In both cases, we can notice a weakening of the leaves which will appear first on the tips. The latter will become more brittle and will be colored with a yellowish or brownish tint.
What can be done?
First of all it is important that the drainage of the soil is well thought out when preparing your substrate. Excessive drainage will not allow the plant to retain the moisture and nutrients necessary for its development. On the contrary, a weak drainage will cause an accumulation of water creating a ground favourable to moulds and fungi. It is essential to let the soil dry between waterings to prevent the roots from soaking in water. But be careful, dry soil on the surface does not mean that the plant is thirsty. The trick is to under-weigh your pots to estimate their water weight, but if this is not possible, simply plant a finger in the pot, the depth of a phalanx. If your finger comes out dry then it’s time to water again.
Heat and burn
Light, whether natural or from lamps, is an essential element for plants, which thanks to it can correctly carry out their photosynthesis and produce energy to develop and flourish. Even if the Cannabis loves to receive a lot of light, it may be that the combination of heat and direct light is too stressful for the plant and may cause drying of the leaves and burns.
What can you do?
Do not hesitate to protect your plants. For the culture in outside, make sure that your plan of Cannabis can benefit from a little shade especially at the hottest hours of the day, by placing it near a tree or by installing a protective veil against the direct sun. On the other hand, if you cultivate in interior using lamps, it will be necessary to try to move the lighting away from the tops of the plant and to ventilate your space well to limit the excess of heat.
Insects and other undesirables
A prolonged exposure to the assaults of insects of all kinds, slugs or gastropods, can cause much stress to your Cannabis plants leading to a weakening or drying of the leaves. And in the worst of the cases it will be necessary to expect to share the buffet or to abandon your small protected at a tragic end.
What can you do?
Be tactical! In order to fight your opponent, you need to know who you’re dealing with, so you can adopt the best technique to repel them. Many natural solutions are very effective such as: black soap against slugs and snails, chilli / garlic mix against aphids, caterpillars and flies. And finally, for Cannabis plants grown in the garden, choose a biodiversity of plants that will have the power to repel some undesirables or on the contrary attract and distract them.
Growing your own marijuana is very rewarding, but it can also be very nerve-wracking, especially when those shiny green leaves begin to turn an ominous yellow and crumble. We sincerely recommend that you follow these recommendations to stop the drying out before it’s too late.