I used to want the easiest marijuana grow room and cultivation program possible. This meant timer-driven, automated fertigation, grow lights, exhaust and C02 systems. Plug and play all the way.
Then I noticed my cannabis plants produce more buds with more potency when I give them specialized inputs and conditions tailored for specific cannabis strains, phenotypes and grow room conditions. I also saw leaf symptoms of nutrients problems similar to those seen in the photo for this article. This realizations radically changed how I feed my plants, leading me to take the time to create customized nutritional programs based on daily plant monitoring and performance analysis. Here’s how it works…
The first thing I do every day is look at grow room conditions. There are times of the year when I run a hotter or cooler grow room, use different lighting spectrums and types of grow lights, and change my root zone media from what I used in the previous cycle. Each of these changes affect my plants’ nutritional needs and performance parameters.
For example, when I run LED grow lights that put out a lot of infrared and ultraviolet wavelengths, my plants need more magnesium and calcium due to increased photosynthesis rates and leaf surface temperatures.
When I run coco coir, my plants need more iron and calcium. Just keeping nutrients water and root zone pH in the ideal range in coco coir is a challenge. Coco coir is tricky!
If I’m running a multiple-strain grow room in bloom phase, my Sativa strains can’t handle the heavy fertilizer load that works great for my Indica strains. Nutrients concentrations that burn Sativas underfeed Indicas. It’s obvious in that type of mixed grow op I need two different feed programs.
If I’m not running drain-to-waste, or have dense root zones with stagnant drainage that are prone to waterlogging, I can’t use nutrients manufacturer’s recommended full-strength dose every watering cycle because the root zone becomes saturated with nutrients salts, and is therefore toxic.
All these things and more are reasons I started customizing my feed program. When you see cannabis leaves looking bad like the leaf featured in this article’s photo, you’re seeing marijuana plants that need customized feeding.
The customization could be as simple as reducing the nutrients load overall so I don’t toxify the root zone with salts. Another method for handling nutrients overload is to flush the root zone every third watering.
When I’ve grown outdoor marijuana plants, feed program customization is even more necessary because the plants experience more stress and less-controllable conditions. For example, last September it rained for two weeks in bloom phase. The plants rarely got any sunshine. Their root zones were oversaturated with rainwater. I collected the rainwater and measured its pH. It was 5.1. Acid rain. Not good for root zone or roots.
I immediately started watering with a very low concentration of base nutrients pH adjusted to 6.5-6.7 to bring the root zone back into ideal range without adding too many nutrients to the zone during a time when lack of photosynthesis meant the plants weren’t using nutrients.
When my plants are experiencing excessive stress from insect attacks, excessive heat or cold, drought, high winds, vapor pressure deficit problems and other causes, I have to feed restorative/protective supplemental formulas including potassium silicate, iron, magnesium, kelp, humic and fulvic acids, carbohydrates and Vitamin B complex.
During bloom phase, I don’t rely on the nutrients manufacturer recommended doses. Instead, I monitor the growth rate, size, and resin gland production of my buds. When I see shortfalls in bud growth and/or resin gland size and production, I adjust my feed program to lower the amount of nitrogen and increase the amount of phosphorus and potassium, while also adding in carbohydrates, enzymes, B vitamins and L-amino acids that boost bud growth and production of cannabinoids and terpenoids.
Does customized nutrients feeding take extra time and thought instead of just following manufacturer’s instructions in a simplistic way? It does. However, I don’t mind doing it because I see it reducing plant performance problems while increasing growth rate, harvest weight and cannabinoid/terpenoid percentages. In fact, I’ve come to enjoy it. It’s like being a master chef, creating your own recipes to make delicious foods nobody else could make!
By now I’m sure you want a versatile nutrients toolkit so you too can customize your feed program. I test nutrients brands, and so far haven’t found one that has everything I want, including timely, helpful grower support. I can only recommend individual products from several different brands. There’s one nutrients brand I’m intrigued by and hope to test, because its founder’s YouTube video seminars show him to be the most knowledgeable nutrients grow expert I’ve ever seen.
So I’ve had to pick and choose from various brands to assemble pure humic and fluvic acid products, and enzyme products, that enhance nutrients absorption and bioavailability while protecting roots. I work hard to source bloom boosters containing kelp, alfalfa extract, and other biostimulant compounds that boost floral taste, scent, and potency. I found hydroponics base nutrients that automatically balance pH to the ideal sweet spot for maximum nutrients absorption.
I have a flushing formula for end of bloom phase that purges excess nutrients salts and other contaminants from plant tissues and the root zone, without interfering with late bloom resin production.
In summary, I want to emphasize the following:
- Nutrients feeding isn’t a one-size-fits-all situation. There are genetic variations within phenotypes and different strains that require tailored feed programs. The varying conditions marijuana plants are grown in can also necessitate a customized feed program.
- Plant growth phase has huge impact on what nutrients your plants need, and how much they need. Many growers fail to fully exploit that fact to feed seedlings, clones, grow phase, transitional phase and bloom phase plants an optimum nutritional line-up with the right dosages.
- Many specialized compounds and nutrients elements contained in kelp, humic and fluvic acids, alfalfa, and other sources aren’t available in most nutrients feed programs.
- Most hydroponics nutrients and so-called organic nutrients fertilizers have inadequate or inferior pH buffers. The nutrients solution and root zone pH can go out of sync quickly, making it hard if not impossible for plants to absorb all the individual nutrients elements they need.
- Growers tend to overfeed and overwater more than they underfeed. You can fix underfeeding a lot more easily than you can fix overfeeding. Overfeeding burns plants roots, and sometimes the plants never fully recover, no matter how many times you flush the root zone. Underfeeding may result in slow growth and lower yields, but at least it doesn’t kill your roots and toxify your plants, and can be easily remedied by increasing your nutrients dosage.
- One of the biggest problems in nutrients products is expired shelf life and dead products. This happens mostly with beneficial microbes and enzymes, but can also happen with humic and fulvic acids, and amino acids. Yet another problem is when manufacturers combine the wrong forms of nutrients elements together, creating lockout, bad pH, and other failures.
- Whatever nutrients brand you use, ask that brand’s tech support if they offer the specialized compounds and formulations mentioned in this article, and how you can use their brand’s product line to customize your cannabis feed program for maximum profitability.
- Be aware that most nutrients programs aren’t properly designed or tested on cannabis plants. The most successful nutrients brands are ones that do plant tissue testing to determine BRIX and other internal plant markers, and adjust their ingredients, ratios, and dosing instructions accordingly.
Yes, creating customized feed programs based on intense monitoring of your plants to give them exactly what they need when they need it takes more time, attention, and knowledge than just following a simplistic recommended dose chart.
You may be one of the lucky growers who can get away with a simplistic nutrients approach. For me and other growers, it’s fantastic to have a customizable nutrients toolkit that allows you to concoct tailored recipes to help your plants thrive and give you more profitable harvests in any situation.