If you lightly tap on the stomp rockets like this:
It's not going to go very high (this one barely made it off of the launcher).
If you stand and do a medium stomp, it'll go higher:
Give it a "hard as you can throw down your foot" stomp and you get it about tree level:
But if you really want to get the stomp rockets stuck in the trees (or really really high up in the sky), you got to put your whole body into it and JUMP!!
Which will be met by the reactions of the people watching your rocket fly up into the sky (and hoping they don't have to do a rocket rescue from the trees):
Another fun thing you can try is playing with the angle of launch (making sure it's not directed into traffic, people, or anywhere dangerous, of course):
Which might surprise you where it goes (or maybe not)
I'll post a few lessons this week on how to make your own stomp rocket launcher from PVC pipe (~$10), paper rockets, and straw rockets. I already posted a lesson on the squeeze rocket launchers which were also part of the fun day. However, I found mini 12oz empty soda bottles are much more resilient to little kid squeezes than small, crumply water bottles. This find was a major improvement to the lesson.
Also, I was looking for replacement rockets since ours got beat up quite a bit from all of the fun and found the whole manufactured launcher kit to be on sale for $10.50 on Amazon (Ultra Stomp Rocket, affiliate link). Also, make your own rockets (which offer a load of extra nerdy science-y goodness) which I will post tomorrow or the next day also work on the store rocket launchers too, so no need to buy extra rockets.
Hope the summer is off to a great start!