Looks like they were grown indoors with insufficient light, (in a window?) and thrown outdoors recently. Or perhaps you found it this way...?

How often do you water, and how much water do you use? What's your water ph? When did you last transplant into the Miracle Grow soil? Do you use any additives or spray with anything?

Once trained to a stake, it's hard to break them of the habit...and the trunk will never fully develop. It will be a fragile bitch in extreme whether conditions, regardless.