I am doing Morning Glories, Moonflower & Sweet Peas for the first time this summer. I have three trellises just up, and the seeds sown in pots that measure 28"x8"X10" deep. A package of each I sowed. How many plants will be to many for each pot? Do I need strings run vertical for each plant? Posting pic of my trellises and location...They are on the west side of the house with sun from noon till about 4:30. Plants will be in pots, with other assorted flower containers arranged in front of the MG, MF, & Sweet Pea vines. I am a Container Gardener. I appreciate any thoughts on this arrangement.....Shirl