Some things about tomatoes
I like reading this link. It has some good information about tomato nutrition. I think learning from other plants can give some ideas for cannabis as well.
- Young plants require and should be provided with lower nutrient concentrations than mature plants, to prevent plants from becoming too vegetative.
- Plants in early fruiting stages require increased levels of specific nutrients like nitrogen (N), calcium (Ca), and potassium (K) because the developing fruits demand greater amounts of these nutrients.
- Mature fruiting plants require the highest levels of nutrients to promote plant growth and fruit development, as well as an appropriate balance of specific nutrients to ensure high fruit quality.
I’ve noticed that some very reliable places usually keep N low during veg, which is odd. There’s a reason though. They give it further down in the page –
In young tomato plants (up to and including Stage 2), the primary concern is limiting the concentration of nitrogen (N) compared to the concentration used for mature plants. Too much N will cause the plants to be overly vegetative, resulting in thick stems, burly and curled leaves, and most importantly, reduced flowering
Later, they recommend only using 90ppm of N in early stages, and increasing during fruiting.
Here’s some formulas from Southern Ag 5-11-26:
In their general schedule, their recommendation for a standard 3/2/1 style recipe is mostly like you’d expect, except a little less Mg that we typically use. 8lbs in 1000 gal is 3.6g per gallon. So their label is a 3.6g-2.4-0.9 ratio, and recommend adding iron in some cases (sequestrene 330 Fe - Iron DPTA).
So you can see, that in their “Early” schedule, there’s only 100ppm N – mirroring the sentiments from OSU.
In their other recipes, they’re also using potassium sulfate and calcium nitrate. Notice that in their “Later” formula, they increase calcium nitrate to 3.6g and add around 0.5g/gal potassium sulfate and 0.23g/gal iron DPTA.
Like the OSU paper said, in the early fruiting stage, the plant needs a lot of N, K and Ca. And in the 5-11-26 formula, those are the big numbers supplied. You don’t normally think of high N in veg for cannabis though. But it’s interesting how they reverse it from how we typically think of growing – which is higher N in veg and lower in flower.