Advice! Should i put plants in ground?

I got two amazing plants that smell great. 1 Purple Cheese and 1 Sour Diesel, they are both outdoor in 15gal pots. They look awesome but the problem lies in size, though they smell great and have crystals. My friend has the same purple cheese clones as i do but they are in the ground(same backyard). I've been feeding them exactly the same stuff (except my friend for some reason likes to use Miracle Grow Bloom..EWWW!) His plants are massive, though, just as chronic- and I know its not the miracle grow... I know that being in the ground and being so big has a correlation if the feeding routine is the same.

So i talked to my GF and asked if i could put my plant in the ground in her vineyard for the rest of flowering season. The answer was yes but I don't want to harm my plant by replanting them. Just like the ground plants in my backyard, i'd dig a really big hole and fill it with foxfarm ocean forest. Mine are about 3 and 1/2ft and his are about 5ft with more bud spots.

Any thoughts? Should I replant?? Pics uploaded later today.
If nutes/additives have relevance, I'm using:

FF Tiger Bloom
GO BioThirve
FF Cha Ching (not yet)
Humic Acid/Kelp
Ca/Mag
Hygrozyme

I have one bag seed female that I took from a 5 gallon bucket about a week ago and put her in the ground like you are talking about doing with a bigger hole and fresh soil...The results so far have been very good she seems to be growing a lot better even in a week I can see the difference...

Its better to not transplant if you other girlfriend has buds already you might end up hurting the plant and losing all you've gained. If you were to dig Two 2square foot holes in the ground your plants will have freedom to grow big and stronger then those in containers but also itd give the plant a better chance of staying alive during short cold rushes in weather. The heat from the ground is often overlooked my friend.. From being posted upo in the state of washington you kinda gotta use nature to its full advantage whether its using the grounds heat or jumping a fence or few to dodge farmers from trying to catch you for stealing their Cow shit for your plants.

Another Tip. Save your money from buying chemicle nutes my friend. Organic is the best way to grow. Better and cleaner taste and much much better results in yield. For huge ass buds put some woodash around the base of the plant if possible mix it into the soil somewhat without disturbing the roots. the water. Garanteed you use potash instead of chemicle you will have more buds then your buddy.