Two types of LEDs, serial - parallel combination
I found ideal to use a combination of Samsung LM301H(https://www.samsung.com/led/lighting/mid-power-leds/3030-leds/lm301h/) and LM351H V2 (https://www.samsung.com/led/lighting/high-power-leds/3535-leds/lh351h-deep-red/).


The efficiency of the red diodes is no better than the whites.  You could get similar results just using white LEDs of the color temperature you want, at least assuming those exist.   


  Is it a great idea to put 6 LM301H together in parallel, series to 1 LM351H?


You'd have to look at the spec sheet to get an idea of the variation in forward voltage, but in general, no I wouldn't prefer that.  Instead I would try to have a few in series so that the variation in individual units averages out and the current is more uniform. Plus the voltage is probably too low to make sense for something like a growlight where you want many watts of power.

Typical grow lights put 10-30 lights in series, and then build parallel strings from that.  This way the current is more reasonable.  Unless you have a very small grow light, usually you want to be working at somewhat higher voltages to reduce wiring losses.