Henry Carter Hull

"Like a bolt from the blue, Jack's little sister Maddy is gone--carried into another realm by an ogre. When Jack and Lilly follow Maddy's captor through the portal, they are ready for anything . . . except what they find waiting for them in the floating crossroads between worlds. Even the power of their magic plants may not be enough to get them back to earth alive. Alone and injured, Jack and Lilly must each face their own monsters--as well as giants...

Jack's family doesn't have a lot of money so his mom works 2 jobs while he watches his sister. One day while they are at the flea market a man offers Jack a trade- a box of seeds for his mom's car keys trade. He makes the trade and the garden that grows from the seeds is magical.

Zita is determined to find her way home to Earth, but her exploits have made her an intergallactic megastar, and as her true self is eclipsed by her public persona, she faces a robot doppelganger, unsure of who she can trust.