diff --git a/Backend/Migrations/Version20250617184300_create_saatgut_tables.php b/Backend/Migrations/Version20250617184300_create_saatgut_tables.php
new file mode 100644
index 0000000..eb73fba
--- /dev/null
+++ b/Backend/Migrations/Version20250617184300_create_saatgut_tables.php
@@ -0,0 +1,58 @@
+<?php declare(strict_types=1);
+
+namespace App\Migrations;
+
+use Doctrine\DBAL\Schema\Schema;
+use Doctrine\Migrations\AbstractMigration;
+
+final class Version20250617184300_create_saatgut_tables extends AbstractMigration
+{
+    public function getDescription(): string
+    {
+        return 'Erstellt die relationalen Tabellen für den Saatgut-Bestand: kategorie, pflanze, saatgut_bestand.';
+    }
+
+    public function up(Schema $schema): void
+    {
+        // 1. Kategorie-Tabelle
+        $this->addSql(<<<SQL
+            CREATE TABLE kategorie (
+                id SERIAL PRIMARY KEY,
+                name VARCHAR(100) NOT NULL UNIQUE,
+                farbe VARCHAR(7) DEFAULT NULL
+            );
+        SQL);
+
+        // 2. Pflanze-Tabelle
+        $this->addSql(<<<SQL
+            CREATE TABLE pflanze (
+                id SERIAL PRIMARY KEY,
+                art_name VARCHAR(200) NOT NULL,
+                sorten_name VARCHAR(200) DEFAULT NULL,
+                kategorie_id INTEGER DEFAULT NULL REFERENCES kategorie(id) ON DELETE SET NULL,
+                beschreibung TEXT DEFAULT NULL
+            );
+        SQL);
+
+        // 3. SaatgutBestand-Tabelle mit Unique Constraint (nutzer_id + pflanze_id)
+        $this->addSql(<<<SQL
+            CREATE TABLE saatgut_bestand (
+                id SERIAL PRIMARY KEY,
+                nutzer_id VARCHAR(255) NOT NULL,
+                pflanze_id INTEGER NOT NULL REFERENCES pflanze(id) ON DELETE CASCADE,
+                menge DOUBLE PRECISION NOT NULL,
+                kaufdatum DATE NOT NULL,
+                ablaufdatum DATE DEFAULT NULL,
+                notizen TEXT DEFAULT NULL,
+                CONSTRAINT unik_nutzer_pflanze UNIQUE (nutzer_id, pflanze_id)
+            );
+        SQL);
+    }
+
+    public function down(Schema $schema): void
+    {
+        $this->addSql('DROP TABLE IF EXISTS saatgut_bestand');
+        $this->addSql('DROP TABLE IF EXISTS pflanze');
+        $this->addSql('DROP TABLE IF EXISTS kategorie');
+    }
+}
diff --git a/Backend/composer.json b/Backend/composer.json
index 7787984..f00cb12 100644
--- a/Backend/composer.json
+++ b/Backend/composer.json
@@ -10,6 +10,7 @@
         "ext-ctype": "*",
         "ext-iconv": "*",
         "doctrine/doctrine-bundle": "*",
+        "doctrine/doctrine-fixtures-bundle": "^4.3",
         "doctrine/orm": "^3.6",
         "lexik/jwt-authentication-bundle": "^3.2",
         "symfony/console": "8.1.*",
@@ -73,5 +74,8 @@
             "allow-contrib": false,
             "require": "8.1.*"
         }
+    },
+    "require-dev": {
+        "phpstan/phpstan": "^2.0"
     }
 }
diff --git a/Backend/composer.lock b/Backend/composer.lock
index b5e3188..556ce3f 100644
--- a/Backend/composer.lock
+++ b/Backend/composer.lock
@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "e6d1737f343b3572fc4b55b50cdc67e2",
+    "content-hash": "8cfcdf73fe44a155dd3b0835cadb01bd",
     "packages": [
         {
             "name": "doctrine/collections",
@@ -92,6 +92,91 @@
             ],
             "time": "2026-01-15T10:01:58+00:00"
         },
+        {
+            "name": "doctrine/data-fixtures",
+            "version": "2.2.1",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/doctrine/data-fixtures.git",
+                "reference": "bf7ac3a050b54b261cedfb3d0a44733819062275"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/doctrine/data-fixtures/zipball/bf7ac3a050b54b261cedfb3d0a44733819062275",
+                "reference": "bf7ac3a050b54b261cedfb3d0a44733819062275",
+                "shasum": ""
+            },
+            "require": {
+                "doctrine/persistence": "^3.1 || ^4.0",
+                "php": "^8.1",
+                "psr/log": "^1.1 || ^2 || ^3"
+            },
+            "conflict": {
+                "doctrine/dbal": "<3.5 || >=5",
+                "doctrine/orm": "<2.14 || >=4",
+                "doctrine/phpcr-odm": "<1.3.0"
+            },
+            "require-dev": {
+                "doctrine/coding-standard": "^14",
+                "doctrine/dbal": "^3.5 || ^4",
+                "doctrine/mongodb-odm": "^1.3.0 || ^2.0.0",
+                "doctrine/orm": "^2.14 || ^3",
+                "doctrine/phpcr-odm": "^1.8 || ^2.0",
+                "ext-sqlite3": "*",
+                "fig/log-test": "^1",
+                "jackalope/jackalope-fs": "*",
+                "phpstan/phpstan": "2.1.46",
+                "phpunit/phpunit": "10.5.63 || 12.5.12",
+                "symfony/cache": "^6.4 || ^7 || ^8",
+                "symfony/var-exporter": "^6.4 || ^7 || ^8"
+            },
+            "suggest": {
+                "alcaeus/mongo-php-adapter": "For using MongoDB ODM 1.3 with PHP 7 (deprecated)",
+                "doctrine/mongodb-odm": "For loading MongoDB ODM fixtures",
+                "doctrine/orm": "For loading ORM fixtures",
+                "doctrine/phpcr-odm": "For loading PHPCR ODM fixtures"
+            },
+            "type": "library",
+            "autoload": {
+                "psr-4": {
+                    "Doctrine\\Common\\DataFixtures\\": "src"
+                }
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "MIT"
+            ],
+            "authors": [
+                {
+                    "name": "Jonathan Wage",
+                    "email": "jonwage@gmail.com"
+                }
+            ],
+            "description": "Data Fixtures for all Doctrine Object Managers",
+            "homepage": "https://www.doctrine-project.org",
+            "keywords": [
+                "database"
+            ],
+            "support": {
+                "issues": "https://github.com/doctrine/data-fixtures/issues",
+                "source": "https://github.com/doctrine/data-fixtures/tree/2.2.1"
+            },
+            "funding": [
+                {
+                    "url": "https://www.doctrine-project.org/sponsorship.html",
+                    "type": "custom"
+                },
+                {
+                    "url": "https://www.patreon.com/phpdoctrine",
+                    "type": "patreon"
+                },
+                {
+                    "url": "https://tidelift.com/funding/github/packagist/doctrine%2Fdata-fixtures",
+                    "type": "tidelift"
+                }
+            ],
+            "time": "2026-04-01T13:56:01+00:00"
+        },
         {
             "name": "doctrine/dbal",
             "version": "4.4.3",
@@ -362,6 +447,92 @@
             ],
             "time": "2026-06-09T19:11:55+00:00"
         },
+        {
+            "name": "doctrine/doctrine-fixtures-bundle",
+            "version": "4.3.1",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/doctrine/DoctrineFixturesBundle.git",
+                "reference": "9e013ed10d49bf7746b07204d336384a7d9b5a4d"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/doctrine/DoctrineFixturesBundle/zipball/9e013ed10d49bf7746b07204d336384a7d9b5a4d",
+                "reference": "9e013ed10d49bf7746b07204d336384a7d9b5a4d",
+                "shasum": ""
+            },
+            "require": {
+                "doctrine/data-fixtures": "^2.2",
+                "doctrine/doctrine-bundle": "^2.2 || ^3.0",
+                "doctrine/orm": "^2.14.0 || ^3.0",
+                "doctrine/persistence": "^2.4 || ^3.0 || ^4.0",
+                "php": "^8.1",
+                "psr/log": "^2 || ^3",
+                "symfony/config": "^6.4 || ^7.0 || ^8.0",
+                "symfony/console": "^6.4 || ^7.0 || ^8.0",
+                "symfony/dependency-injection": "^6.4 || ^7.0 || ^8.0",
+                "symfony/deprecation-contracts": "^2.1 || ^3",
+                "symfony/doctrine-bridge": "^6.4.16 || ^7.1.9 || ^8.0",
+                "symfony/http-kernel": "^6.4 || ^7.0 || ^8.0"
+            },
+            "conflict": {
+                "doctrine/dbal": "< 3"
+            },
+            "require-dev": {
+                "doctrine/coding-standard": "14.0.0",
+                "phpstan/phpstan": "2.1.11",
+                "phpunit/phpunit": "^10.5.38 || 11.4.14"
+            },
+            "type": "symfony-bundle",
+            "autoload": {
+                "psr-4": {
+                    "Doctrine\\Bundle\\FixturesBundle\\": "src"
+                }
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "MIT"
+            ],
+            "authors": [
+                {
+                    "name": "Fabien Potencier",
+                    "email": "fabien@symfony.com"
+                },
+                {
+                    "name": "Doctrine Project",
+                    "homepage": "https://www.doctrine-project.org"
+                },
+                {
+                    "name": "Symfony Community",
+                    "homepage": "https://symfony.com/contributors"
+                }
+            ],
+            "description": "Symfony DoctrineFixturesBundle",
+            "homepage": "https://www.doctrine-project.org",
+            "keywords": [
+                "Fixture",
+                "persistence"
+            ],
+            "support": {
+                "issues": "https://github.com/doctrine/DoctrineFixturesBundle/issues",
+                "source": "https://github.com/doctrine/DoctrineFixturesBundle/tree/4.3.1"
+            },
+            "funding": [
+                {
+                    "url": "https://www.doctrine-project.org/sponsorship.html",
+                    "type": "custom"
+                },
+                {
+                    "url": "https://www.patreon.com/phpdoctrine",
+                    "type": "patreon"
+                },
+                {
+                    "url": "https://tidelift.com/funding/github/packagist/doctrine%2Fdoctrine-fixtures-bundle",
+                    "type": "tidelift"
+                }
+            ],
+            "time": "2025-12-03T16:05:42+00:00"
+        },
         {
             "name": "doctrine/event-manager",
             "version": "2.1.1",
@@ -4865,7 +5036,72 @@
             "time": "2026-05-29T05:06:50+00:00"
         }
     ],
-    "packages-dev": [],
+    "packages-dev": [
+        {
+            "name": "phpstan/phpstan",
+            "version": "2.2.2",
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/phpstan/phpstan/zipball/e5cc34d491a90e79c216d824f60fe21fd4d93bd6",
+                "reference": "e5cc34d491a90e79c216d824f60fe21fd4d93bd6",
+                "shasum": ""
+            },
+            "require": {
+                "php": "^7.4|^8.0"
+            },
+            "conflict": {
+                "phpstan/phpstan-shim": "*"
+            },
+            "bin": [
+                "phpstan",
+                "phpstan.phar"
+            ],
+            "type": "library",
+            "autoload": {
+                "files": [
+                    "bootstrap.php"
+                ]
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "MIT"
+            ],
+            "authors": [
+                {
+                    "name": "Ondřej Mirtes"
+                },
+                {
+                    "name": "Markus Staab"
+                },
+                {
+                    "name": "Vincent Langlet"
+                }
+            ],
+            "description": "PHPStan - PHP Static Analysis Tool",
+            "keywords": [
+                "dev",
+                "static analysis"
+            ],
+            "support": {
+                "docs": "https://phpstan.org/user-guide/getting-started",
+                "forum": "https://github.com/phpstan/phpstan/discussions",
+                "issues": "https://github.com/phpstan/phpstan/issues",
+                "security": "https://github.com/phpstan/phpstan/security/policy",
+                "source": "https://github.com/phpstan/phpstan-src"
+            },
+            "funding": [
+                {
+                    "url": "https://github.com/ondrejmirtes",
+                    "type": "github"
+                },
+                {
+                    "url": "https://github.com/phpstan",
+                    "type": "github"
+                }
+            ],
+            "time": "2026-06-05T09:00:01+00:00"
+        }
+    ],
     "aliases": [],
     "minimum-stability": "stable",
     "stability-flags": {},
diff --git a/Backend/config/bundles.php b/Backend/config/bundles.php
index 4fa1f41..0086e24 100644
--- a/Backend/config/bundles.php
+++ b/Backend/config/bundles.php
@@ -5,4 +5,5 @@ return [
     Doctrine\Bundle\DoctrineBundle\DoctrineBundle::class => ['all' => true],
     Symfony\Bundle\SecurityBundle\SecurityBundle::class => ['all' => true],
     Lexik\Bundle\JWTAuthenticationBundle\LexikJWTAuthenticationBundle::class => ['all' => true],
+    Doctrine\Bundle\FixturesBundle\DoctrineFixturesBundle::class => ['dev' => true, 'test' => true],
 ];
diff --git a/Backend/config/packages/doctrine.yaml b/Backend/config/packages/doctrine.yaml
index 290611c..8831fb1 100644
--- a/Backend/config/packages/doctrine.yaml
+++ b/Backend/config/packages/doctrine.yaml
@@ -17,9 +17,9 @@ doctrine:
             App:
                 type: attribute
                 is_bundle: false
-                dir: '%kernel.project_dir%/src/Entity'
-                prefix: 'App\Entity'
-                alias: App
+                dir: '%kernel.project_dir%/src/Data/Doctrine/Entity/Saatgut'
+                prefix: 'App\Data\Doctrine\Entity\Saatgut'
+                alias: Saatgut
 
 when@test:
     doctrine:
diff --git a/Backend/phpstan.neon b/Backend/phpstan.neon
new file mode 100644
index 0000000..6d84ee4
--- /dev/null
+++ b/Backend/phpstan.neon
@@ -0,0 +1,7 @@
+parameters:
+    level: 8
+    paths:
+        - src
+    ignoreErrors:
+        # Symfony Kernel has some generic unused methods that are technically framework internals.
+        - '#Method App\\Kernel::getAllowedEnvs\(\) is unused#'
diff --git a/Backend/src/Data/Doctrine/Entity/Saatgut/KategorieEntity.php b/Backend/src/Data/Doctrine/Entity/Saatgut/KategorieEntity.php
new file mode 100644
index 0000000..997a677
--- /dev/null
+++ b/Backend/src/Data/Doctrine/Entity/Saatgut/KategorieEntity.php
@@ -0,0 +1,48 @@
+<?php declare(strict_types=1);
+
+namespace App\Data\Doctrine\Entity\Saatgut;
+
+use Doctrine\ORM\Mapping as ORM;
+
+#[ORM\Entity]
+class KategorieEntity
+{
+    #[ORM\Id]
+    #[ORM\GeneratedValue(strategy: 'IDENTITY')]
+    #[ORM\Column(type: 'integer')]
+    public ?int $id = null;
+
+    #[ORM\Column(type: 'string', length: 100, unique: true)]
+    private string $name;
+
+    #[ORM\Column(type: 'string', length: 7, nullable: true)]
+    private ?string $farbe = null;
+
+    public function __construct(string $name, ?string $farbe = null)
+    {
+        $this->name = $name;
+        $this->farbe = $farbe;
+    }
+
+    public function getId(): ?int
+    {
+        return $this->id;
+    }
+
+    public function getName(): string
+    {
+        return $this->name;
+    }
+
+    public function getFarbe(): ?string
+    {
+        return $this->farbe;
+    }
+
+    public function setFarbe(?string $farbe): self
+    {
+        $this->farbe = $farbe;
+
+        return $this;
+    }
+}
diff --git a/Backend/src/Data/Doctrine/Entity/Saatgut/PflanzeEntity.php b/Backend/src/Data/Doctrine/Entity/Saatgut/PflanzeEntity.php
new file mode 100644
index 0000000..706a8d1
--- /dev/null
+++ b/Backend/src/Data/Doctrine/Entity/Saatgut/PflanzeEntity.php
@@ -0,0 +1,84 @@
+<?php declare(strict_types=1);
+
+namespace App\Data\Doctrine\Entity\Saatgut;
+
+use Doctrine\ORM\Mapping as ORM;
+
+#[ORM\Entity]
+class PflanzeEntity
+{
+    #[ORM\Id]
+    #[ORM\GeneratedValue(strategy: 'IDENTITY')]
+    #[ORM\Column(type: 'integer')]
+    public ?int $id = null;
+
+    #[ORM\Column(type: 'string', length: 200)]
+    private string $artName;
+
+    #[ORM\Column(type: 'string', length: 200, nullable: true)]
+    private ?string $sortenName = null;
+
+    #[ORM\Column(type: 'integer', nullable: true)]
+    private ?int $kategorieId = null;
+
+    #[ORM\Column(type: 'text', nullable: true)]
+    private ?string $beschreibung = null;
+
+    public function __construct(
+        string $artName,
+        ?string $sortenName = null,
+        ?int $kategorieId = null,
+        ?string $beschreibung = null,
+    ) {
+        $this->artName = $artName;
+        $this->sortenName = $sortenName;
+        $this->kategorieId = $kategorieId;
+        $this->beschreibung = $beschreibung;
+    }
+
+    public function getId(): ?int
+    {
+        return $this->id;
+    }
+
+    public function getArtName(): string
+    {
+        return $this->artName;
+    }
+
+    public function getSortenName(): ?string
+    {
+        return $this->sortenName;
+    }
+
+    public function setSortenName(?string $sortenName): self
+    {
+        $this->sortenName = $sortenName;
+
+        return $this;
+    }
+
+    public function getKategorieId(): ?int
+    {
+        return $this->kategorieId;
+    }
+
+    public function setKategorieId(?int $kategorieId): self
+    {
+        $this->kategorieId = $kategorieId;
+
+        return $this;
+    }
+
+    public function getBeschreibung(): ?string
+    {
+        return $this->beschreibung;
+    }
+
+    public function setBeschreibung(?string $beschreibung): self
+    {
+        $this->beschreibung = $beschreibung;
+
+        return $this;
+    }
+}
diff --git a/Backend/src/Data/Doctrine/Entity/Saatgut/SaatgutBestandEntity.php b/Backend/src/Data/Doctrine/Entity/Saatgut/SaatgutBestandEntity.php
new file mode 100644
index 0000000..6fbcc87
--- /dev/null
+++ b/Backend/src/Data/Doctrine/Entity/Saatgut/SaatgutBestandEntity.php
@@ -0,0 +1,118 @@
+<?php declare(strict_types=1);
+
+namespace App\Data\Doctrine\Entity\Saatgut;
+
+use Doctrine\ORM\Mapping as ORM;
+
+#[ORM\Entity]
+#[ORM\Table(name: 'saatgut_bestand')]
+#[ORM\UniqueConstraint(name: 'unik_nutzer_pflanze', columns: ['nutzer_id', 'pflanze_id'])]
+class SaatgutBestandEntity
+{
+    #[ORM\Id]
+    #[ORM\GeneratedValue(strategy: 'IDENTITY')]
+    #[ORM\Column(type: 'integer')]
+    public ?int $id = null;
+
+    #[ORM\Column(type: 'string', length: 255)]
+    private string $nutzerId;
+
+    #[ORM\Column(type: 'integer')]
+    private int $pflanzeId;
+
+    #[ORM\Column(type: 'float')]
+    private float $menge;
+
+    #[ORM\Column(type: 'date')]
+    private \DateTimeInterface $kaufdatum;
+
+    #[ORM\Column(type: 'date', nullable: true)]
+    private ?\DateTimeInterface $ablaufdatum = null;
+
+    #[ORM\Column(type: 'text', nullable: true)]
+    private ?string $notizen = null;
+
+    public function __construct(
+        string $nutzerId,
+        int $pflanzeId,
+        float $menge,
+        \DateTimeInterface $kaufdatum,
+        ?\DateTimeInterface $ablaufdatum = null,
+        ?string $notizen = null,
+    ) {
+        $this->nutzerId = $nutzerId;
+        $this->pflanzeId = $pflanzeId;
+        $this->menge = $menge;
+        $this->kaufdatum = $kaufdatum;
+        $this->ablaufdatum = $ablaufdatum;
+        $this->notizen = $notizen;
+    }
+
+    public function getId(): ?int
+    {
+        return $this->id;
+    }
+
+    public function getNutzerId(): string
+    {
+        return $this->nutzerId;
+    }
+
+    public function getPflanzeId(): int
+    {
+        return $this->pflanzeId;
+    }
+
+    public function setPflanzeId(int $pflanzeId): self
+    {
+        $this->pflanzeId = $pflanzeId;
+
+        return $this;
+    }
+
+    public function menge(): float
+    {
+        return $this->menge;
+    }
+
+    public function setMenge(float $menge): self
+    {
+        $this->menge = $menge;
+
+        return $this;
+    }
+
+    public function kaufdatum(): \DateTimeInterface
+    {
+        return $this->kaufdatum;
+    }
+
+    public function setKaufdatum(\DateTimeInterface $kaufdatum): self
+    {
+        $this->kaufdatum = $kaufdatum;
+
+        return $this;
+    }
+
+    public function ablaufdatum(): ?\DateTimeInterface
+    {
+        return $this->ablaufdatum;
+    }
+
+    public function setAblaufdatum(?\DateTimeInterface $ablaufdatum): self
+    {
+        $this->ablaufdatum = $ablaufdatum;
+
+        return $this;
+    }
+
+    public function notizen(): ?string
+    {
+        return $this->notizen;
+    }
+
+    public function setNotizen(?string $notizen): void
+    {
+        $this->notizen = $notizen;
+    }
+}
diff --git a/Backend/src/Data/Doctrine/Repository/Saatgut/KategorieRepository.php b/Backend/src/Data/Doctrine/Repository/Saatgut/KategorieRepository.php
new file mode 100644
index 0000000..906f687
--- /dev/null
+++ b/Backend/src/Data/Doctrine/Repository/Saatgut/KategorieRepository.php
@@ -0,0 +1,29 @@
+<?php declare(strict_types=1);
+
+namespace App\Data\Doctrine\Repository\Saatgut;
+
+use App\Data\Doctrine\Entity\Saatgut\KategorieEntity;
+use Doctrine\Bundle\DoctrineBundle\Repository\ServiceEntityRepository;
+use Doctrine\Persistence\ManagerRegistry;
+
+/**
+ * @extends ServiceEntityRepository<KategorieEntity>
+ */
+class KategorieRepository extends ServiceEntityRepository
+{
+    public function __construct(ManagerRegistry $registry)
+    {
+        parent::__construct($registry, KategorieEntity::class);
+    }
+
+    /**
+     * @return string[]
+     */
+    public function getAllNames(): array
+    {
+        return array_map(
+            fn(KategorieEntity $k) => $k->getName(),
+            $this->findAll()
+        );
+    }
+}
diff --git a/Backend/src/Data/Doctrine/Repository/Saatgut/PflanzeRepository.php b/Backend/src/Data/Doctrine/Repository/Saatgut/PflanzeRepository.php
new file mode 100644
index 0000000..dbd1d5b
--- /dev/null
+++ b/Backend/src/Data/Doctrine/Repository/Saatgut/PflanzeRepository.php
@@ -0,0 +1,46 @@
+<?php declare(strict_types=1);
+
+namespace App\Data\Doctrine\Repository\Saatgut;
+
+use App\Data\Doctrine\Entity\Saatgut\PflanzeEntity;
+use Doctrine\Bundle\DoctrineBundle\Repository\ServiceEntityRepository;
+use Doctrine\Persistence\ManagerRegistry;
+
+/**
+ * @extends ServiceEntityRepository<PflanzeEntity>
+ */
+class PflanzeRepository extends ServiceEntityRepository
+{
+    public function __construct(ManagerRegistry $registry)
+    {
+        parent::__construct($registry, PflanzeEntity::class);
+    }
+
+    /**
+     * Find plants by category ID (flat, no joins)
+     * @return PflanzeEntity[]
+     */
+    public function findByKategorieId(int $kategorieId): array
+    {
+        return $this->createQueryBuilder('p')
+            ->andWhere('p.kategorieId = :kategorieId')
+            ->setParameter('kategorieId', $kategorieId)
+            ->orderBy('p.artName', 'ASC')
+            ->getQuery()
+            ->getResult();
+    }
+
+    /**
+     * Find plant by exact art name and sort name (flat query)
+     */
+    public function findByArtUndSorte(string $artName, string $sortenName): ?PflanzeEntity
+    {
+        return $this->createQueryBuilder('p')
+            ->andWhere('p.artName = :artName')
+            ->andWhere('p.sortenName = :sortenName')
+            ->setParameter('artName', $artName)
+            ->setParameter('sortenName', $sortenName)
+            ->getQuery()
+            ->getOneOrNullResult();
+    }
+}
diff --git a/Backend/src/Data/Doctrine/Repository/Saatgut/SaatgutBestandRepository.php b/Backend/src/Data/Doctrine/Repository/Saatgut/SaatgutBestandRepository.php
new file mode 100644
index 0000000..0a6800a
--- /dev/null
+++ b/Backend/src/Data/Doctrine/Repository/Saatgut/SaatgutBestandRepository.php
@@ -0,0 +1,47 @@
+<?php declare(strict_types=1);
+
+namespace App\Data\Doctrine\Repository\Saatgut;
+
+use App\Data\Doctrine\Entity\Saatgut\SaatgutBestandEntity;
+use Doctrine\Bundle\DoctrineBundle\Repository\ServiceEntityRepository;
+use Doctrine\Persistence\ManagerRegistry;
+
+/**
+ * @extends ServiceEntityRepository<SaatgutBestandEntity>
+ */
+class SaatgutBestandRepository extends ServiceEntityRepository
+{
+    public function __construct(ManagerRegistry $registry)
+    {
+        parent::__construct($registry, SaatgutBestandEntity::class);
+    }
+
+    /**
+     * Get inventory items for a specific user (flat query via ID reference)
+     * @return SaatgutBestandEntity[]
+     */
+    public function findByNutzerId(string $nutzerId): array
+    {
+        return $this->createQueryBuilder('s')
+            ->andWhere('s.nutzerId = :nutzerId')
+            ->setParameter('nutzerId', $nutzerId)
+            ->orderBy('s.kaufdatum', 'DESC')
+            ->getQuery()
+            ->getResult();
+    }
+
+    /**
+     * Check if a specific user already has this plant in inventory (to enforce unique constraint semantically)
+     */
+    public function existsByNutzerUndPflanze(string $nutzerId, int $pflanzeId): bool
+    {
+        return (bool) $this->createQueryBuilder('s')
+            ->select('COUNT(s.id)')
+            ->andWhere('s.nutzerId = :nutzerId')
+            ->andWhere('s.pflanzeId = :pflanzeId')
+            ->setParameter('nutzerId', $nutzerId)
+            ->setParameter('pflanzeId', $pflanzeId)
+            ->getQuery()
+            ->getSingleScalarResult();
+    }
+}
diff --git a/Backend/src/DataFixtures/AppFixtures.php b/Backend/src/DataFixtures/AppFixtures.php
new file mode 100644
index 0000000..987f6fe
--- /dev/null
+++ b/Backend/src/DataFixtures/AppFixtures.php
@@ -0,0 +1,17 @@
+<?php
+
+namespace App\DataFixtures;
+
+use Doctrine\Bundle\FixturesBundle\Fixture;
+use Doctrine\Persistence\ObjectManager;
+
+class AppFixtures extends Fixture
+{
+    public function load(ObjectManager $manager): void
+    {
+        // $product = new Product();
+        // $manager->persist($product);
+
+        $manager->flush();
+    }
+}
diff --git a/Backend/src/DataFixtures/KategorieFixtures.php b/Backend/src/DataFixtures/KategorieFixtures.php
new file mode 100644
index 0000000..828de5f
--- /dev/null
+++ b/Backend/src/DataFixtures/KategorieFixtures.php
@@ -0,0 +1,32 @@
+<?php declare(strict_types=1);
+
+namespace App\DataFixtures;
+
+use App\Data\Doctrine\Entity\Saatgut\KategorieEntity;
+use Doctrine\Bundle\FixturesBundle\Fixture;
+use Doctrine\Persistence\ObjectManager;
+
+class KategorieFixtures extends Fixture
+{
+    private const array KATEGORIEN = [
+        ['name' => 'Gemüse', 'farbe' => '#4CAF50'],
+        ['name' => 'Kräuter', 'farbe' => '#8BC34A'],
+        ['name' => 'Blumen', 'farbe' => '#E91E63'],
+        ['name' => 'Obst',   'farbe' => '#FF9800'],
+    ];
+
+    public function load(ObjectManager $manager): void
+    {
+        foreach (self::KATEGORIEN as $data) {
+            $kategorie = new KategorieEntity(
+                name: $data['name'],
+                farbe: $data['farbe'],
+            );
+
+            $this->addReference("kategorie-{$data['name']}", $kategorie);
+            $manager->persist($kategorie);
+        }
+
+        $manager->flush();
+    }
+}
diff --git a/Backend/src/DataFixtures/PflanzeFixtures.php b/Backend/src/DataFixtures/PflanzeFixtures.php
new file mode 100644
index 0000000..e55f125
--- /dev/null
+++ b/Backend/src/DataFixtures/PflanzeFixtures.php
@@ -0,0 +1,47 @@
+<?php declare(strict_types=1);
+
+namespace App\DataFixtures;
+
+use App\Data\Doctrine\Entity\Saatgut\KategorieEntity;
+use App\Data\Doctrine\Entity\Saatgut\PflanzeEntity;
+use Doctrine\Bundle\FixturesBundle\Fixture;
+use Doctrine\Common\DataFixtures\DependentFixtureInterface;
+use Doctrine\Persistence\ObjectManager;
+
+class PflanzeFixtures extends Fixture implements DependentFixtureInterface
+{
+    /**
+     * @return class-string<Fixture>[]
+     */
+    public function getDependencies(): array
+    {
+        return [KategorieFixtures::class];
+    }
+
+    private const array PFLANZEN = [
+        ['artName' => 'Tomate', 'sortenName' => 'Stelzer', 'kategorie' => 'Gemüse'],
+        ['artName' => 'Paprika', 'sortenName' => 'Habanero', 'kategorie' => 'Gemüse'],
+        ['artName' => 'Basilikum', 'sortenName' => 'Genovese', 'kategorie' => 'Kräuter'],
+        ['artName' => 'Salbei', 'sortenName' => null, 'kategorie' => 'Kräuter'],
+        ['artName' => 'Sonnenblume', 'sortenName' => 'Riesenblume', 'kategorie' => 'Blumen'],
+        ['artName' => 'Erdbeere', 'sortenName' => 'Senga Sengana', 'kategorie' => 'Obst'],
+    ];
+
+    public function load(ObjectManager $manager): void
+    {
+        foreach (self::PFLANZEN as $data) {
+            $kategorie = $this->getReference("kategorie-{$data['kategorie']}", KategorieEntity::class);
+
+            $pflanze = new PflanzeEntity(
+                artName: $data['artName'],
+                sortenName: $data['sortenName'] ?? null,
+                kategorieId: $kategorie->getId(),
+                beschreibung: "Katalogeintrag für {$data['artName']}",
+            );
+
+            $manager->persist($pflanze);
+        }
+
+        $manager->flush();
+    }
+}
diff --git a/Backend/symfony.lock b/Backend/symfony.lock
index e303a63..c653066 100644
--- a/Backend/symfony.lock
+++ b/Backend/symfony.lock
@@ -22,6 +22,18 @@
             "src/Repository/.gitignore"
         ]
     },
+    "doctrine/doctrine-fixtures-bundle": {
+        "version": "4.3",
+        "recipe": {
+            "repo": "github.com/symfony/recipes",
+            "branch": "main",
+            "version": "3.0",
+            "ref": "1f5514cfa15b947298df4d771e694e578d4c204d"
+        },
+        "files": [
+            "src/DataFixtures/AppFixtures.php"
+        ]
+    },
     "lexik/jwt-authentication-bundle": {
         "version": "3.2",
         "recipe": {
@@ -34,6 +46,9 @@
             "config/packages/lexik_jwt_authentication.yaml"
         ]
     },
+    "phpstan/phpstan": {
+        "version": "2.2.2"
+    },
     "symfony/console": {
         "version": "8.1",
         "recipe": {