Cannabis plants are highly (pun intended) resilient. As implied by the nickname “weed”, they’ll grow without nutrients—even producing buds here and there. However, if you want to maximize hydroponic yields and get the green, sticky buds you see in magazine photos, you’ll need to use nutrients at the right times.
Under- or over-feeding will affect yields and can, in some cases, kill your precious plants. That’s why it’s so important to know how often to nourish your hydroponic crop. We’ll cover that—and a few other subjects—in this comprehensive guide.
Feeding Cannabis Plants: How Often Should It Happen?
Even when using American seeds of consistent high quality, every cannabis crop is different. That’s why there’s no universal answer to that question. The schedule provided by the nutrient blend’s manufacturer is a great place to start, though you’ll need to watch the plants closely and adjust dosages as needed. In most cases, growers shouldn’t precisely follow the dosage recommendation on the bag or box.
Nutrient manufacturers stand to profit if your supply is exhausted sooner—and for that reason, the recommended dosage is typically higher than needed. We suggest starting with about half the listed amount and moving upward from there. As for the frequency with which feedings should occur, hydroponic cannabis nutrient schedules are given on a weekly basis. While some growers feed once per week, others spread it out over several feedings.
Reading the Feed Chart
As mentioned earlier, most nutrient brands offer feed charts as a convenience. Proper interpretation of these charts is key to giving your plants the right nourishment at the right time. Feed charts usually set out 12- to 13-week growing cycles. One axis of the chart will list the cycle’s weeks, while the other may include the type and dosage of nutrients the plants should receive during each week of their life cycle.
Nutrients are typically given once per week, and most brands will offer a feed-to-water ratio in gallons or liters. Some charts also give PPM (parts per million) ranges for their nutrient solutions. If that’s the case, we suggest buying a PPM meter and measuring the solution before feeding. Once the plants have been fed, check the water’s PPM to ensure that they’re absorbing the right nutrients.
Feeding During the Vegetative Stage
The hydroponic system should be up and running for at least 24 hours before any seedlings are introduced. It’s important to monitor the water temperature closely, to ensure it stays at about 70 degrees Fahrenheit. If you’re having trouble keeping the water warm enough, use an aquarium heater.
For water that’s too warm, just add a bit of cold water. Be sure to check the grow room’s temperature and humidity every day, or every other day at minimum. Because the vegetative phase is so crucial to the health, root growth, and vitality of cannabis plants, it’s important to ensure that they get plenty of nitrogen.
Adding Nutrients During Flowering: When Should You Do It?
The answer to that question is the same as it was in the beginning of our guide—simply refer to the feed chart provided by the nutrient blend’s manufacturer. That typically means once-a-week feedings, but some growers give smaller doses more frequently. Keep it simple, though—if your hydroponic setup is doing its job, you shouldn’t need to feed your plants more than two or three times per week.
Before harvest, give the plants a few water-only feedings to remove the nutrients from the buds before they’re harvested. Buds laden with fertilizer just don’t burn well or taste good! The manufacturer’s nutrient feed chart should have the flushing period listed.
Determining the Frequency Hydroponically Grown Cannabis Plants Should Be Fed
As mentioned before, numerous factors determine how often your plants need feeding. In the sections below, we’ll look at the most essential ones
Growth Stages
Cannabis plants’ nutrient requirements vary depending on their current life stage. Not only do their needs differ in terms of dosage, but also in the amount of each nutrient. As you may have already guessed, younger plants don’t need as many nutrients as budding ones—and seedlings grown from our award-winning seeds don’t need to be fed at all for the first few weeks when grown in soil.
Once the plants are well into the vegetative stage, it’s best to start them on a nutrient blend and increase the dosage gradually. Remember, vegging plants need a great deal of nitrogen. When they’ve entered the flowering phase, they’ll need less nitrogen and more potassium. Increase the amount of nutrients until the end of flowering, when feeding stops and the plants are flushed with clean water.
Growth Medium
The growth medium you use has a significant effect on the plants’ nutrient needs. For instance, those who grow in coco coir need to use more nutrients because the medium contains none. Soil gardens, on the other hand, come with nutrients—so these growers may feed their plants less often. In fact, some soils are so nutrient-dense that growers can get away with not feeding their plants at all for the first several weeks!
Hydroponic cannabis gardens are different, though. If you’re growing a hydro crop, you’ll need to ensure the precision of nutrient PPM and monitor levels constantly.
Nutrient Types
Different nutrient lines come in various concentrations. If your nutrient blend is more concentrated, you’ll need to feed less often; if it’s diluted, you can feed more often. Follow the nutrient blend manufacturer’s feed chart—but cut the dosage a little for the best results.
Detecting and Resolving Nutrition Problems in Cannabis Plants
The recommendations we’ve given here are only a basic guideline and starting point. To ensure the success of your crop, you’ll need to make changes along the way. The plants will tell you what they need, but you’ll have to learn their language. Here, we’ll look at some of the most common nutrition issues in cannabis plants, as well as the signs plants will show when these problems arise.
Nutrient Burn
When cannabis plants are getting a surplus of minerals, nutrient burn will occur. It means that they’re either overfed or there’s a nutrient buildup in the water. Generally, you’ll see dark green leaves with brownish-yellow tips that curl upward. The plants’ stems will be dark purple or red. If the issue isn’t resolved, the discoloration will spread until it covers the entire leaf. During the flowering phase, the sugar leaves and calyxes may turn yellow and shrivel up. Prevent nutrient burn by lowering the dosage and increasing it gradually. Make things easier for yourself, and track everything the plants receive. If the plants are already burned, flush them thoroughly with pH-neutral water for seven days before feeding them again.
Nutrient Deficiency
In cannabis plants, most nutrient deficiencies are caused by lockout or underfeeding. The most well-known symptoms of a deficiency are dry leaves and stems that turn rusty, brown, or yellow. You’ll find other, more specific symptoms related to various micro- and macronutrients in the detailed charts we offer here at kindseed.com.
To treat nutrient deficiencies, it’s not as simple as feeding more nutrients. Before acting, you’ll need to determine why the deficiency occurred. If a shortfall is caused by a lockout, increasing the dosage will make things worse.
Lockout
A nutrient lockout happens when something prevents cannabis plants from absorbing important nutrients, such as a pH imbalance or nutrient buildup around the plants’ roots. An excess of any nutrient can inhibit the proper absorption of others. As far as pH is concerned, each vital nutrient is optimally absorbed within a narrow pH range.
Thankfully, there’s an overlap; all nutrients are absorbed adequately at a pH of 5.8 for hydroponic gardens. To solve problems related to nutrient lockout, flush the plants with pH-neutral water. Then, set the right pH level for proper absorption. Once that’s been done, you can start feeding the plants again.
Feed Your Plants Well—And Enjoy a Healthy, Abundant, and Flavorful Crop
The frequency with which cannabis plants are fed isn’t as important as the amount of each nutrient they receive. While it’s possible to feed more often, doing so will require a reduction in nutrient dosage. Or you can feed once a week, but you’ll need to give the plants all their nutrients at once.
The level of nourishment the plants need will depend on various factors. To increase the chances of success, take the amount recommended in the manufacturer’s feed chart and divide it in half. Start there and increase the dosage slowly, while monitoring the crop closely. While cannabis plants are resilient, they’ll let you know when something’s wrong. Thankfully, most issues are easy to resolve.
Growing cannabis hydroponically may seem like a complex endeavor, but it’s very rewarding—especially when you end up with a bushel of sticky, sweet, and resinous buds. The best hydroponic crops start with the highest quality seeds, and that’s what you’ll find here at kindseed.com. Browse our selection of seeds online or call today to talk to one of our friendly and knowledgeable seed selection experts.
