A 1 or 2-gallon black growing container will help accomplish your goal. Black absorbs Spring and Summer heat extremely well, providing excellent warmth for rapid root system growth. Plenty of fertilizer, water and sunlight with organic soil and minimal pruning for a couple years will accumulate a ton of foliage, sugars, carbs, vascular tissue, and beef up the tree.
One of my Juniper Procumbens went from:
To:
in just a few months with the first application in March, using 10-10-10 granular fertilizer (4 even piles, evenly spaced and imbedded beneath soil surface).
You can repeat application 6 months later but in different places:
Routine watering when soil feels dry, lots of sunlight, and the tree should photosynthesize and feed itself nicely over the next couple years (or whenever you’re happy with its size and density).
You can likely use a liquid/fast-release fertilizer once or twice a month in addition to the 10-10-10 set in place, but I took the slower route since I wanted to be extra cautious learning horticulture and track the growth safely.
Lastly, you can ask 10 different people and receive 10 different pieced of advice, so do what works best for you and according to how your tree responds.
Happy growing!