Transplantation

This spell among others inspired me to make Druid Guerrilla fighters.

Quote from Drakkonus >>

So is there an official ruling from Jeremy Crawford or someone about how many creatures can enter the Transport via Plants? 

1 round = everybody takes a turn. 1 round is approximately 6 seconds. Since the spell duration is measured in rounds (1 round), the caster could use an action to cast the spell and step through. Then on subsequent turns during the same combat round, any creature (enemies too) can use their movement on their own turn to reach the entrance tree + 5 feet of movement to step through. At the beginning of the caster's next turn, the 1 round duration ends, and so does the spell.

When out of combat, or if a LOT of people are around, I would leave it up to the DM. Vox Machina (Critical Role) once evacuated 20+ people this way, but that was Matt's interpretation. As a DM, I would allow up to 10 people by default, but if a party tried to coordinate more people rushing through, I would have them set the queue order and required an Acrobatics check from everyone with a DC based on their rank in the queue (e.g., 14th in line = DC 14). Anyone who fails would trip and themselves + anyone after them would be prevented from stepping through.

So, say you carried a large potted plant around with you... Does this become a mobile teleportation item? 

Quote from NitrusXide >>

So, say you carried a large potted plant around with you... Does this become a mobile teleportation item? 

The plant would have to be Large so carrying it around with you might be difficult.... but yes. The spell doesn't say that the EXIT plant needs to be Large, but I think that's a fair interpretation. If you had two as ships with a live tree in place of the mast, a druid could move between the ships, even if they have moved. The link is between the plants, not the places. Now, the roots of a large tree would also take up a fair amount of space, and a big tree is very heavy... but it could be made to work. It's could be cool to have ocean going druids with ships with a big fat palm trees instead of masts.

Or on land, maybe you could use animate objects and have the trees "walk" to where you need them, and then TvP back to a base camp.

ALSO: Feather Tokens can make trees that are actual permanent living trees, if you really needed to you could drop a feather token, create a huge oak tree, and use that

Great spell to use when making a fancy pot into a magic item...

Quote from juniperjupiterr >>

What if the plant were re-planted? Would I come out somewhere unexpected or would the spell just not work?

I treat this as a Druid version to Teleportation, because that is just what it is.   The advantage is no failure table, Bad thing is you would have had to seen or touched the destination tree.  Replanting a large or larger tree is difficult, but not impossible, so I would say you'd turn up in the trees new location.  

Also, it's essentially a teleportation circle, so definitely can allow multiple people/creatures to go through.  if you are organized enough I would allow 10 or 12 people to move through safely (5 foot movement required to use, lasts for 1 round) assuming single file.  If the tree you use on both ends is large enough to take advantage of the full 10FT diameter you could double or maybe even triple the number allowed through in 1 round.  

Does this work on an Animated Tree? 

It is a plant and Huge :D

“Large or larger inanimate plant”
Animated Plant is unsuitable by its own name.

Step 1: Touch tree

Step 2: Get your druid circle to work some magic and throw the tree to the moon

Step 3: Cast this spell on another tree on the ground

Step 4: Enjoy free and permanent access to the moon whenever you want

Step 5: ???

Step 6: Profit

Interestingly, while the target plant has to be Large or larger, it does not state that the destination plant has to be. However, as a DM, I might rule that it does. Even if it doesn't, you might prefer to pick one that is, as you may want to be able to make the trip in reverse later by recasting the spell.

I love you, Pocket DM.

In my campaign i could throw some seeds on the ground make them grow way faster and almost instantly make a portal.

Does the destination tree need to be inanimate? Could I use an awakened tree as mobile fortress that can be Transported too?

Quote from Assault006 >>

You're right 

How about Plantsport.

Plantsport is already a thing. It's the vegan version of buzkashi.

How about "Treelaport?"

Sorry.I'll let myself out. 

Waga Baba Bobo