1 and 2 part nutrients
are usually available in separate ‘Grow’ and ‘Bloom’ formulations. 3-part
nutrients incorporate the ‘Grow’ and ‘Bloom’ formula across all 3
containers.
Note that plants take up nutrients in a ratio which is essentially
independent of the nutrient ratios present in the nutrient. This is
particularly noticeable when comparing the growth phase (i.e. vegetative)
with the bloom (i.e. flowering / fruiting) phase.
Growth Phase
In the growth phase,
plants have a particularly high demand for nitrogen. Consequently, “Grow”
nutrients contain a relatively high concentration of nitrogen. Their use
helps ensure plants do not run out of nitrogen prematurely.
Bloom Phase
In the bloom phase, the demand for phosphorus and potassium increases. Consequently,
“Bloom” nutrients contain a relatively high concentration of both
phosphorus and potassium, but relatively low nitrogen. Hence, switching
to ‘Bloom’ during the flowering phase will help ensure plants do not
become deficient in potassium and phosphorus (especially for heavy
fruiting plants such as tomatoes and strawberries).
The use of ‘Grow’ and ‘Bloom’ nutrients at the appropriate times is also
much more economical because for example, the use of ‘Bloom’ during the
growth phase would result in excessive phosphorus and potassium being
wasted. This wasted nutrient potentially becomes an environmental concern
when the nutrient is dumped – particularly in large commercial operations.
