On collection changed, trap the added item and put some logic and set value for it

oncollectionchange

partial void Plants_Changed(NotifyCollectionChangedEventArgs e)
{
    if (e.Action == NotifyCollectionChangedAction.Add)
    {
        var addedItem = e.NewItems[0] as HaulerPlant;
        if (addedItem == null) return;

        addedItem.IsActive = true;

    }
}