Laravel 5.1 validation rule alpha cannot take whitespace

You can use a Regular Expression Rule that only allows letters, hyphens and spaces explicitly:

public function rules()
{
    return [
        'name'     => 'required|regex:/^[\pL\s\-]+$/u',
        'email'    => 'email|unique:users,email',
        'password' => 'required',
        'phone'    => 'required|numeric',
        'address'  => 'required|min:5',
    ];
}

You can create a custom validation rule for this since this is a pretty common rule that you might want to use on other part of your app (or maybe on your next project).

on your app/Providers/AppServiceProvider.php

/**
 * Bootstrap any application services.
 *
 * @return void
 */
public function boot()
{
    //Add this custom validation rule.
    Validator::extend('alpha_spaces', function ($attribute, $value) {

        // This will only accept alpha and spaces. 
        // If you want to accept hyphens use: /^[\pL\s-]+$/u.
        return preg_match('/^[\pL\s]+$/u', $value); 

    });

}

Define your custom validation message in resources/lang/en/validation.php

return [

/*
|--------------------------------------------------------------------------
| Validation Language Lines
|--------------------------------------------------------------------------
|
| The following language lines contain the default error messages used by
| the validator class. Some of these rules have multiple versions such
| as the size rules. Feel free to tweak each of these messages here.
|
*/
// Custom Validation message.
'alpha_spaces'         => 'The :attribute may only contain letters and spaces.',

'accepted'             => 'The :attribute must be accepted.',
 ....

and use it as usual

public function rules()
{
    return [
        'name'     => 'required|alpha_spaces',
        'email'    => 'email|unique:users,email',
        'password' => 'required',
        'phone'    => 'required|numeric',
        'address'  => 'required|min:5',
    ];
}