Weed Ca and Mg requirements compared to veggies?

[BreezyGreens]

Intermediate gardener and extremely novice weed grower here with a question... can anyone give me good info on Ca and Mg requirements for autoflower cannabis (cultivars are EZ Bake auto and Alpha CBD auto from Trilogene) compared to, let's say, tomato plants?

I'm growing everything - veg and weed - in soil on a balcony in USDA zone 7, and I used Down to Earth's greenstone basalt as a Ca, Mg, and Fe soil amendment for all the plants. My tomatoes, all varieties started early from seed and fed weekly with basic Miracle Grow (no Ca, Mg, or Fe, according to the package), have formed a massive jungle, they're covered with flowers, immature tomatoes, and they're thriving. I have a lighter soil composition for the weed, and I'm feeding them with Down to Earth's cactus and succulent fertilizer and will be adding a bit of wood ash from the bbq to boost potassium.

If my tomatoes are showing no signs of Ca or Mg deficiencies, is it a safe bet to say that my weed, which is looking pretty good (save for a suspected slight N deficiency which I'm fixing), is all right in that regard too?

[Rootsruler]

Short answer? Yes. Tomato and weed have very similar nutrient requirements. I would be more worried about micro nutrients for your weed if your tomatoes are doing well. Post a few pictures of the status of your weed plant from different angles. Leaf closeups are a good way to see if there are any beginnings of deficiencies. Weed is a voracious feeder and grower if it's given the correct range of conditions. Using DTE's Cactus formula will result in N def, which you already noted. My personal opinion is that weed likes lots of N in the beginning through veg and then medium to semi light throughout the rest of the grow.

Here's a chart I like to use that illustrates the plants needs through its growth cycles. The only thing I would change is to introduce an uptick in calcium and magnesium earlier.


Actual care of photo period vs auto flower seeds is identical other than the genetic timeline autos have that needs to be considered when vegging.

Because you are an intermediate gardener I would suggest you grow femenized photo period seeds on your next run so that any mistakes that are made can be fixed prior to moving into the flowering period and you get to know how to read your plants. Photoperiod seeds flower through circadian rhythm together with photoreceptor protein, such as phytochrome or cryptochrome, to sense seasonal changes in night length, or photoperiod, which they take as signals to flower. Autos have been genetically modified to flower without the photoperiod signaling.

Your gardening knowledge will help propel you into the intermediate or pro ranks quickly. For some reason, new weed growers seem to think that because the seeds are named "auto" they are easier to grow. IMO, autos are finicky and their genetically limited veg time is a negative in my book. Any mistakes you make in veg will result in lower dry yields.

If your plants are doing well I'm guessing your balcony gets direct sun exposure for a good amount of the day. If not, I would suggest you purchase a supplemental light to give your cannabis plants the amount of light energy they need to thrive. Weed is a light whore and will take a good amount of PPFD.

I'm an indoor grower with lots of outdoor experience. I prefer growing indoors due to my having control over as many parameters as possible.

[BreezyGreens]

Thanks for the info! I like the chart.

This first try is seeing what growing weed is like. I was worried about overfeeding, but I've gone too far in the other direction.

I absolutely hear you about photoperiod plants. The balcony gets 6-8 hours of direct sun during peak growing season, but it drops off in the fall. I decided on autos because of overall climate, and also there's a fair amount of artificial light at night. Setting up an indoor grow sounds like a fun thing to do, but I don't have time and space right now. Definitely a thing I would try in the future, though.

[Rootsruler]

Cool! If it's working go with it!!!