To change a plants death settings go to the plants blueprint so for example the BP_TomatoPlant and select the BP_PlantComponent in the Components panel, then in the Details panel and inside the Plant Settings Category find the Death category like the image below.

Here you can change this plants Death settings, you can hover your mouse over each settings name to get a tooltip with more info about each setting.

Destruction Settings

You can enable or disable the Use Destruction Mesh on Death setting which controls if a destruction mesh is spawned in the plants location when it dies.

Death Destruction Mesh Hide Time is the amount of time in seconds after the destruction mesh is spawned that it is destroyed.

Destruction Mesh

To set the Destruction mesh that will be used go to the plant’s blueprint and in the functions menu click the override button and select to override the AddDestructionMesh function, if the option isnt there the function might already be in use, so look in the functions tab for the AddDestructionMesh function and open it up.

In that function you can add code that will add code that will create a destruction mesh component, this code will depend on if you are using UE4 or UE5. You can also look at or copy the code in the AddDestructionMesh function in any of the include plants to see how they are setup.

To change the destruction mesh that will be used select the Add Destruction Component (UE4) or the Add Geometry Collection (UE5) node and in the details panel you can set the destruction mesh (UE4) or the Rest Collection (UE5) these settings are the destruction mesh that will be used.

If you do copy the code from an existing plant remember to change the static mesh inputs on the == nodes as they control which destruction mesh is spawned depending on the plants current mesh, this allows you to set a different destruction mesh depending on what the plants current mesh is set to.