Here is how and where to plant or summon Reality Saplings using Reality Seeds in Fortnite Battle Royale.
Chapter 3, Season 3 is finally live in Fortnite and is available to play. There are many new mechanics that have been added to the game, such as being able to ride certain animals, such as the Boars and Wolves. When you are riding an animal, you can also equip your weapon and shoot at enemies, without dismounting, providing they do not kill the animal you are on!
The challenges for the first week of Fortnite are also live and one of the challenges you need to complete is to plant or summon Reality Saplings using Reality Seeds and this post will show you exactly where you can find these and what you need to do in order to complete the challenge.

Where to Plant or Summon Reality Saplings Using Reality Seeds in Fortnite
One of the new items that have been added in Fortnite for Chapter 3, Season 3 is the Reality Seeds and there are a couple of places in which you can find it. One of the places you can land is at the new POI called Reality Falls, which is located west of Tilted Towers.
Once here, you will need to position yourself on the root where you will see a seed pod on top. You will need to destroy the seed pod in order to release the Reality Seeds inside. Here is what the seed pod looks like:

Once you have broken the seed pod, you will see Reality Seeds shoot in the sky from the pod. There are three that are released from the pod so make sure you keep your eye on them as they will land in different places. Once you are close enough to one, you will have the option to pick it up.

Maybe a better place to land is just east of Rave Cave as there are a couple of seed pods you can find there.
Once you have picked up the seed, all you need to do is equip it and throw it in a place it can be thrown to complete part of the challenge. You will need to do this two more times in order to complete the challenge and be awarded 15,000 XP. It can be completed in one match as it does drop three seeds, but there are a lot of players completing the challenge at the moment, so you may need to do it multiple matches.