diff --git a/internal/service/plants_test.go b/internal/service/plants_test.go
index bdd36cf..d5111a7 100644
--- a/internal/service/plants_test.go
+++ b/internal/service/plants_test.go
@@ -9,7 +9,7 @@ import (
 	"gitea.stevedudenhoeffer.com/steve/pansy/internal/domain"
 )
 
-func intPtr(n int) *int { return &n }
+func ptrInt(n int) *int { return &n }
 
 // validPlant is a well-formed PlantInput for tests to tweak.
 func validPlant(name string) PlantInput {
@@ -53,7 +53,7 @@ func TestCreatePlantIsOwnedAndTrimmed(t *testing.T) {
 	owner := seedUser(t, s, "a@example.com")
 
 	in := validPlant("  Purple basil  ")
-	in.DaysToMaturity = intPtr(60)
+	in.DaysToMaturity = ptrInt(60)
 	p, err := s.CreatePlant(context.Background(), owner, in)
 	if err != nil {
 		t.Fatalf("CreatePlant: %v", err)
@@ -147,7 +147,7 @@ func TestUpdatePlantClearsDays(t *testing.T) {
 	s := newTestService(t, openConfig())
 	owner := seedUser(t, s, "a@example.com")
 	in := validPlant("Dill")
-	in.DaysToMaturity = intPtr(50)
+	in.DaysToMaturity = ptrInt(50)
 	p, _ := s.CreatePlant(context.Background(), owner, in)
 
 	// SetDays with nil clears; absent (SetDays=false) would leave it.
@@ -191,7 +191,7 @@ func TestCreatePlantValidation(t *testing.T) {
 		{Name: "x", Category: domain.CategoryHerb, SpacingCM: 10, Color: "nope", Icon: "🌿"},           // bad color
 		{Name: "x", Category: domain.CategoryHerb, SpacingCM: 10, Color: "#4a7c3f", Icon: ""},          // empty icon
 		{Name: strings.Repeat("x", maxPlantNameLen+1), Category: domain.CategoryHerb, SpacingCM: 10, Color: "#4a7c3f", Icon: "🌿"}, // name too long
-		{Name: "x", Category: domain.CategoryHerb, SpacingCM: 10, Color: "#4a7c3f", Icon: "🌿", DaysToMaturity: intPtr(0)},         // days must be >= 1
+		{Name: "x", Category: domain.CategoryHerb, SpacingCM: 10, Color: "#4a7c3f", Icon: "🌿", DaysToMaturity: ptrInt(0)},         // days must be >= 1
 	}
 	for i, in := range bad {
 		if _, err := s.CreatePlant(context.Background(), owner, in); !errors.Is(err, domain.ErrInvalidInput) {
@@ -202,7 +202,7 @@ func TestCreatePlantValidation(t *testing.T) {
 	// A shorthand hex (#rgb) and a set days value pass.
 	ok := validPlant("Thyme")
 	ok.Color = "#0a0"
-	ok.DaysToMaturity = intPtr(90)
+	ok.DaysToMaturity = ptrInt(90)
 	if _, err := s.CreatePlant(context.Background(), owner, ok); err != nil {
 		t.Errorf("valid plant rejected: %v", err)
 	}
diff --git a/internal/store/store_test.go b/internal/store/store_test.go
index 97eeb64..bb2c74c 100644
--- a/internal/store/store_test.go
+++ b/internal/store/store_test.go
@@ -2,9 +2,12 @@ package store
 
 import (
 	"context"
+	"errors"
 	"path/filepath"
 	"strings"
 	"testing"
+
+	"gitea.stevedudenhoeffer.com/steve/pansy/internal/domain"
 )
 
 // openTestDB opens a fresh file-backed DB in a temp dir and migrates it.
@@ -88,6 +91,44 @@ func TestForeignKeysEnforced(t *testing.T) {
 	}
 }
 
+func TestDeletePlantForeignKeyBackstop(t *testing.T) {
+	db := openTestDB(t)
+	ctx := context.Background()
+
+	// Seed a user → garden → object → custom plant, then a planting referencing
+	// the plant. DeletePlant must surface the ON DELETE RESTRICT FK as
+	// ErrPlantInUse (not a raw 500-worthy error) — this pins isForeignKeyViolation's
+	// string-match so a driver-message change is caught here rather than in prod.
+	// The service normally blocks this via a count pre-check; here we hit the
+	// store backstop directly (the lost-race path).
+	insert := func(q string, args ...any) int64 {
+		res, err := db.SQL().ExecContext(ctx, q, args...)
+		if err != nil {
+			t.Fatalf("seed exec %q: %v", q, err)
+		}
+		id, err := res.LastInsertId()
+		if err != nil {
+			t.Fatalf("last insert id: %v", err)
+		}
+		return id
+	}
+	uid := insert(`INSERT INTO users (email, display_name) VALUES ('a@b.c', 'A')`)
+	gid := insert(`INSERT INTO gardens (owner_id, name, width_cm, height_cm) VALUES (?, 'G', 100, 100)`, uid)
+	oid := insert(`INSERT INTO garden_objects (garden_id, kind, x_cm, y_cm, width_cm, height_cm) VALUES (?, 'bed', 0, 0, 10, 10)`, gid)
+	pid := insert(`INSERT INTO plants (owner_id, name, category, spacing_cm, color, icon) VALUES (?, 'Basil', 'herb', 25, '#4a7c3f', '🌿')`, uid)
+	insert(`INSERT INTO plantings (object_id, plant_id, x_cm, y_cm, radius_cm) VALUES (?, ?, 0, 0, 10)`, oid, pid)
+
+	if err := db.DeletePlant(ctx, pid); !errors.Is(err, domain.ErrPlantInUse) {
+		t.Fatalf("DeletePlant on referenced plant = %v, want ErrPlantInUse", err)
+	}
+
+	// Clearing the reference lets the delete succeed.
+	insert(`DELETE FROM plantings WHERE plant_id = ?`, pid)
+	if err := db.DeletePlant(ctx, pid); err != nil {
+		t.Errorf("DeletePlant after clearing reference: %v", err)
+	}
+}
+
 func TestCheckConstraintRejectsBadEnum(t *testing.T) {
 	db := openTestDB(t)