by Nebula Haze
Which Cannabis Supplements Are Actually Necessary to Grow Great Weed?
“This is what puzzles me most, is all the cannabis nutrient companies have a “basic” nutrient line and then they have all the “extra” stuff they want you to give the plant to make big better buds. You can read in forums that growers think the extra stuff rocks and other say that it sucks. The companies all claim theirs is the best. I have not seen a study that shows bigger buds are more potent or even healthier. I wonder if it is like when you compare an organically grown apple to a non-organic apple. The Non-organic one is bigger and shiner but the taste and texture (the important things) do not compare to the organic one. Are all the “extra” really better or would the plant be happier without them?”
~ BuddMarsh
Oooh, this is a great question! So here’s the thing. You don’t need supplements. Cannabis growers only need base nutrients, and that’s it. You can get all the way to harvest with the most amazing and top-quality buds ever, with even cheap base nutrients and nothing else.
However, obviously, it’s more complicated than just that.
One thing I’ll say, and when you talk to growers who have tried a lot of different nutrient lines, you’ll often hear this…
Your environment and growing skill have a MUCH bigger effect on your final results than the specific nutrient system or supplements you use.
Learn how to grow cannabis in this setup.
I’ve tried several different cannabis nutrient brands and tons of different cannabis supplements. It can be really difficult to tell the difference in results. Experienced growers (especially growers who have done actual testing) usually tell you the same thing, “If your nutrients are growing good weed, they’re good nutrients”. Any quality cannabis nutrients can keep your plants green and fast-growing in the vegetative stage, then produce big clean buds in the flowering stage.
3 Examples of Great Base Nutrients for Cannabis (click to learn more):
- General Hydroponics – Soil, Coco Coir & Hydroponics
- Fox Farm – Soil & Coco Coir
- Dyna-Gro – Soil, Coco Coir & Hydroponics
Note: Use Nutrients and Supplements from the Same Company
When it comes to nutrients and supplements, it helps avoid problems if you get all your products from the same brand or company. This increases the chance they’ll all “play nicely” together and won’t cause unexpected interactions. So if you get your nutrients from General Hydroponics, try to stick to their supplements. If you get your nutrients from Botanicare, try to stick to their supplements, etc.
If possible, try to get all your nutrients and supplements from the same company.
These Supplements Work for Cannabis Plants
Besides nutrients, there are some supplements that have a well-established use:
Root Rot Prevention (Root Inoculant)
A root supplement like Hydroguard is really important if growing in hydroponics to prevent your roots from being attacked by root rot. But if your plants aren’t being attacked by root rot, it doesn’t really make much difference. There are also other more generalized root-promoting supplements.
Hydroguard is effective at preventing root rot in a hydroponic reservoir.
Prevent Problems with Purified Water (Cal-Mag Supplement)
You may want to add a Cal-Mag supplement if your water is very “soft” and doesn’t naturally contain a lot of minerals, like if you’re using filtered, reverse osmosis, or distilled water, to prevent Calcium or Magnesium deficiencies. A Cal-Mag supplement replaces some of the minerals that are normally found in water. Cal-Mag also helps stabilize the pH of your nutrient water, which can swing wildly in purified water because it doesn’t have much “buffer”. Cal-Mag is popular for coco growers because cannabis grown in coco coir tends to have somewhat higher Calcium needs. However, if your plant doesn’t need Calcium or Magnesium, adding a Cal-Mag supplement won’t make much difference.
If you’ve got soft or purified water, you may need a Cal-Mag supplement. Most nutrient companies offer some form of Cal-Mag. One popular option is CaliMagic.
Stronger Stems & Heat Resistance (Silica supplement)
Silica is often found abundantly in water, but if you don’t have a lot of silica in your water, your plant’s cell walls won’t be nearly as strong. As a result, if your plant is low on silica, it has weaker stems and is more susceptible to heat stress. However, like other cannabis supplements, adding silica when you don’t need it doesn’t make a positive difference. Silica can get deposited in buds, and since it’s actually incorporated in the cell walls, you can’t “flush” it out like some other nutrients. Therefore it’s recommended you stop giving a silica supplement after you see buds start forming. I’m of the opinion that there’s no need to use silica since you can hold plants up with plant yo-yos, tomato cages or stakes. Why put something into the plant (that you know can get deposited in buds but isn’t necessary for healthy growth) if you can use a mechanical solution instead?
Silica supplements can make cannabis plants more hardy and heat resistant, but only use if needed. One popular Silica supplement is Silica Blast.
Bud Supplements (PK Boosters, Bulking Formulas, Shooting Powders, etc.)
These add high levels of P & K. If you’re not giving your plants specially made flowering nutrients, they need another source of extra P and K. So for example, if you are growing in soil and haven’t been adding extra nutrients in the water, a PK booster may be perfect in the flowering stage to make up for what the plant has used up in the soil.
These types of products often contain naturally occurring plant hormones to help stimulate flowering, but those ingredients are not listed on the label. The downside is these hormones can sometimes cause plants to herm or grow male flowers (which can result in seedy buds), though typically that only happens when a strain is already prone to herming. Make sure to avoid synthetic plant growth hormones!
PK Boosters, Bulking Formulas, and Shooting Powders, Oh my!
Do you need Bud Supplements? No!
If you’re using a cannabis nutrient system with great base nutrients, you don’t need any special bud supplements to grow great buds. For beginners, I highly recommend trying a full grow with just base nutrients, so you don’t run into any of the potential side effects that can appear with some bud supplements.
Example: These plants were grown using just Dyna-Gro Grow & Bloom. I used “Grow” for the vegetative stage and “Bloom” for the flowering stage at about 1 tsp/gallon. No supplements whatsoever! Read my guide to using Dyna-Gro nutrients for growing weed including a custom watering schedule for cannabis.
Strains are Pacific Punch (limited edition strain related to Purple Punch), Amnesia Lemon Pie, and Zweet Inzanity. I grew these plants in coco with just Dyna-Gro nutrients under a Mars Hydro TSL2000 LED using 5-gallon fabric pots.
Grown with only base nutrients and no supplements. Check out the full grow journal!
Check out the resulting bud quality!
What to Keep in Mind with Cannabis Supplements
So the main theme of supplements is that the ones which make the biggest difference have specific uses for the plant. If the plant doesn’t need it, adding a supplement can sometimes do nothing, or even worse it could hurt your plant. For example, if you add a powerful PK booster when you’re already giving full strength base flowering nutrients, you could burn or even kill your plants.
Don’t Go Overboard: Use Cannabis Supplements for a Specific Reason!
There is no reason to use a ton of supplements in addition to your base nutrients. Too many supplements at once can often cause cannabis problems like nutrient burn, herming, and other unusual symptoms. Try to pick just 1 or 2 of the supplements that seem the most appealing to you, and start slowly. Or simplify your life and grow only with good base nutrients.
This cannabis grower got a root supplement, base nutrients, one flowering supplement, Cal-Mag, and a Silica supplement. This is a lot, but any more would be total overkill!
Then you’ve got supplements that don’t necessarily “fix” a problem, but “enhance.”
Which Supplements “Enhance” Buds or Growth?
- Sugar and Carbohydrate-based supplements – These claim to increase potency and trichome production, and may increase bulk. However, I’m not 100% certain they add anything but sugar to the buds. The reason I say that is if a grower uses a lot of these types of supplements the plant can start oozing sugar sap. If you taste the sap, it’s sweet and not potent at all. I almost wonder if that extra “weight” is just sugar being stored in the buds and doesn’t necessarily add to the potency. Some of these products, like the Botanicare Sweet Carbo Line, not only include sugar, but also certain terpenes and esters that are stored unchanged in plant buds, giving your buds unique subtle flavors and a generally sweet smell.
- Other Enhancers – Then there are the more nebulous types of supplements that are meant to give overall improvements. For example supplements with Amino Acids, Vitamins, and other non-essential plant compounds. These are a lot harder to measure the results. I’m sure some of them do what they say, while others are basically snake oil. It’s a lot harder to prove one way or the other with these because it’s difficult to test unless you do a big side-by-side controlled experiment with a bunch of plants. And unfortunately, the industry just hasn’t quite reached that point yet!
Certain supplements may increase potency, smells, and “sparkle” of buds.
Improve Smell of Buds
Although I haven’t tried this yet, I’m really intrigued by Botanicare’s Sweet Carbo line. According to Botanicare:
The natural esters in Sweet are easily absorbed by the plant, but are not broken down further once deposited within the plant tissue. This means that as new flowers develop they will contain small amounts of these natural esters which contribute to the overall flavor and aroma of the finished product.
They offer citrus, berry, grape, and “raw” (which is just a generally sweet smell). These should be used throughout the flowering stage to help build smell/flavor in the buds as they mature. However, since these contain a small but significant amount of magnesium, they should not be used while flushing during the last 2-3 weeks before harvest. At this point, the smells have already been deposited into the buds. Another cool thing about these supplements is they contain amino acids and some other enhancers, so it’s kind of like getting a lot of different products at once.
The Botanicare Sweet Carbo line offers cannabis supplements to make buds smell like berry, grape, or “raw” sugar (a generally sweet smell). It seems like the original “Raw” version is the most popular. It imparts a sweet smell, but tends to accent the strain’s natural smell as opposed to try to cover it up.
A cheap alternative to expensive sugar-based bloom boosting supplements is blackstrap molasses. Giving this to your plants for the last few weeks before harvest can help them get bigger and smell/taste better. It’s not specially made for plants; it’s the regular stuff you’ll find in your kitchen or at the grocery store. Blackstrap molasses adds sugars, amino acids and trace minerals. Unfortunately for hydro growers, anything organic like molasses is not suitable for a hydroponic reservoir! But molasses works great for soil and coco growers 🙂
For last 2-3 weeks before harvest, give 1/2 tsp of Blackstrap Molasses per gallon when watering (for soil or coco coir)
Bloom Enhancers & “Ripeners”
The jury is still out and which is the most effective supplement, but many growers are happy with bloom-promoting supplements that include sources of…
- amino acids
- humic acids
- vitamins
- trace minerals
- often contain unlisted ingredients (including natural or synthetic plant growth hormones)
I personally don’t use this type of supplement so I can’t recommend a particular one, but some of the most popular cannabis supplements based on this type of formula include…
Note: When possible, try to get all your nutrients and supplements from the same company. This greatly reduces the chance of getting unexpected reactions between the different products. Some companies don’t “play well” together.
Mineral vs Organic Nutrients
The biggest difference I’ve noticed has been between nutrients that use mineral sources of nutrients vs organic sources. I feel like (in my experience) the mineral/chemical nutrients tend to get slightly faster vegetative growth and sometimes increased bud potency at harvest. Plants with organic nutrients grow slower in the vegetative stage and tend to produce buds with a stronger/more complex smell at harvest. But the difference is relatively small and you can definitely still get really smelly buds with mineral nutrients, and you can get really potent buds with organic nutrients!
When it comes to bud quality, it’s important to give the right nutrients so that your plant is healthy and vibrant, but other than that I think focusing on the environment (especially maintaining high light levels and proper temperature/humidity) have a much bigger effect on your final bud quality than your specific brand of nutrients or the specific supplements you use!
Jump to…
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