Those trees, in my opinion, are too large for those containers. If they stay in those containers for the summer the roots will start circling. Saying that, they should be planted now. If you put them in a larger container you could keep them at your house and water regularly. Then you can plant them this fall when they are starting dormancy or are already dormant.I'm planning on buying some trees from Walmart when they get in stock. I am not sure how often I will be able to water them this summer. Am I better off keeping them at my house where I can regularly water and waiting to plant this fall or is it better to get them in the ground?
Which ever way you choose I recommend using weed mats and grow tubes. Weed mats eliminate competition from grass and weeds. They also retain moisture in the ground and condense in the heat of summer and add moisture. Grow tubes add protection from rabbits and deer. Also Plantra sun flex tubes are like double walled so they condense in the heat of the summer and add moisture.