Using a spray bottle, rather than a watering can, will help overzealous growers keep hydration under control. Give seedlings a light misting when the surrounding soil has begun to dry and your plants should flourish in no time. Once a root system has developed, you can switch to watering routines that will see you all the way through to harvest. In line with the guidance above, watering should take place every 2–3 days, or when the surrounding soil is dry to the touch.
The most effective way to get into good habits with watering is to water at the start of the day. For outdoor cultivations, plants will have an entire day of sunlight to utilise. If growing indoors, it is helpful to set your grow lights to come on at the start of the day, just as you are watering. Watering in the evening is an option, but the lower evening and nighttime temperatures can lead to a buildup of mould. Consistency in watering routines supports another vital building block of cannabis—nutrition. Your plant's root system will absorb essential nutrients from its growing medium, but only when pH levels are optimal (6.0–7.0 pH for soil, 5.5–6.5 for hydro/soilless/coco). Not only does it keep plants routinely hydrated, but it will prevent fluctuations in pH—a symptom diagnosed by brown spots on middle or lower leaves. To maximise nutrient uptake, aim for 10–20% runoff every time you water. Adopting this approach at an early stage should keep pH fluctuations to a minimum.
However, it is especially vital if you are increasing nutrient concentrations for any reason (bloom boosters during flowering, for example). If you are still noticing problems with your cannabis (deformed leaves, fungus, or spots), it could be the pH of your water that's the problem. No matter how skilled you are at balancing the pH of soil, water that is too acidic or alkaline can throw all your calculations into disarray. Use a pH tester to make sure you have a level playing field BEFORE you start to use pH-up or down to maintain an ideal window. Overwatering vs Underwatering Marijuana: How can I tell if my droopy cannabis plant is over or under-watered? A common question for new cannabis growers is how to tell if your drooping cannabis seedling is over or under-watered. It’s common for new growers to overwater their weed, but that doesn’t mean that underwatering doesn’t happen too. Never fear, once you get a feel for it, it’s easy to tell how often you should be feeding your plant and what is the true cause of your drooping. If your marijuana shows signs of drooping in normal temperatures, it almost always means you’re over or under-watering your plants, either by watering too often, or by giving too much water at a time when the plant is too young to drink it all. Water your marijuana when the top of the growing medium starts feeling dry up to your first knuckle. Wait if it’s damp, but water your plant once it feels dry. Give More Water at a Time (if that doesn’t work, you may need to transplant to a bigger pot) Soil takes more than 3 days to dry? An over watered cannabis plant will have leaves that are full of water, so the leaves will be firm to the touch and generally curling down (even from the stem of the leaf) almost as if it has too much water weight to hold the leaf out straight. An under watered cannabis plant will have leaves that are brittle, limp, and lifeless. They will need to be watered every day just to keep them wet. The leaves will seem to be drooping but won’t appear as rounded and full as an over watered cannabis plant. Leaves feel papery and thin on an underwatered plant, growing medium is dry. Now that you’ve (hopefully) got an idea about whether it’s over watering or underwatering, what’s the cure? Symptoms: seedling is droopy, growing medium is moist, damping off. Most common causes: When a cannabis plant is “overwatered” it has less to do with the water and more to do with oxygen. Plants can even grow directly in water (hydroponics) but in order to thrive, roots need oxygen .
In hydroponics, that’s accomplished by dissolving oxygen into the water. But when plants are grown in a container, too much water = not enough oxygen. When a plant’s roots are sitting in water, they quickly use up all the oxygen until the growing medium starts to dry out. Without enough oxygen at the roots, the plant will start showing symptoms of oxygen deprivation. Luckily, there are many steps you can take to prevent overwatering your cannabis plants.
While overwatering can display many different symptoms, most overwatered cannabis plants look droopy, like this… Despite what seems like an obvious cause, several different scenraios can end in overwatering. Here are some of the most common trouble-makers: Big Pot, Small Seedling. When you have a small plant in a very big pot, it’s easy to overwater because the roots aren’t drinking much yet, and the big container takes a long time to dry out. Notice how the plants in smaller containers have grown more than the plant that was put in a big container as a seedling.