Thank you for answering! I did forget to mention that it was suppose to be a Dwarf, does that matter any on the pot size? As for repotting, what type of soil would you recommend? Would a bag of tree and shrub soil work? I water thoroughly when the soil is dry.

It would also be helpful to know where you are.

Being a dwarf really doesn't have much bearing on the container size - the roots will still grow :-) Can't see all that clearly, but that looks to be a 1G nursery pot, which is typically used here as a starter size for small, 1-2 y.o. grafts (24-30" or so tall). I immediately pot up to a larger size container and since I use a very durable, fast draining soil mix, I often go up quite a lot in size.........generally around a 5G container at least.

The potting soil you should be using is something formulated specifically for containers - a soil-less mix. Preferably bark based (rather than peat or coir) and with a fair proportion of perlite/pumice or grit, like the 5-1-1 or gritty mixes discussed in the Container Gardening forum.

Or you can just plant in the ground in a suitable location.

It could be getting either too little or too much water. Also do you have the Japanese Maple sited in Full sun? Not all Japanese Maples can handle Full Sun and prefer afternoon shade. A dwarf tree means it will grow slower and take longer to outgrow the container. That's assuming it hasn't already outgrown it. Make sure the bag says Potting mix and not Garden soil. Garden soil should not be used for container plants.

gardengal, I'm in zone seven. I'd love to plant in ground if possible, I just have clay soil and figured it would be better to plant it in a pot. I have a five gallon pot that I can pot it in as soon as I have the soil, so I'll have to take a look in that forum! Stuartlawrence, I let the soil get to where it's dried completely before watering deeply again. Right now I have it on the porch where it has shade all day

Sound like you're on the right track.

When re-potting the Japanese Maple I would loosen the roots if the tree is root bound (going around in a circle).