diff --git a/packages/web/src/components/CreateInitiativeDialog.tsx b/packages/web/src/components/CreateInitiativeDialog.tsx
index 0d70a2c..338e23d 100644
--- a/packages/web/src/components/CreateInitiativeDialog.tsx
+++ b/packages/web/src/components/CreateInitiativeDialog.tsx
@@ -33,7 +33,6 @@ export function CreateInitiativeDialog({
   const [name, setName] = useState("");
   const [projectIds, setProjectIds] = useState<string[]>([]);
   const [executionMode, setExecutionMode] = useState<"yolo" | "review_per_phase">("review_per_phase");
-  const [mergeTarget, setMergeTarget] = useState("");
   const [error, setError] = useState<string | null>(null);
 
   const utils = trpc.useUtils();
@@ -48,7 +47,7 @@ export function CreateInitiativeDialog({
         createdAt: new Date().toISOString(),
         updatedAt: new Date().toISOString(),
         mergeRequiresApproval: true,
-        mergeTarget: 'main',
+        branch: null,
         projects: [],
       };
       utils.listInitiatives.setData(undefined, (old = []) => [tempInitiative, ...old]);
@@ -73,7 +72,6 @@ export function CreateInitiativeDialog({
       setName("");
       setProjectIds([]);
       setExecutionMode("review_per_phase");
-      setMergeTarget("");
       setError(null);
     }
   }, [open]);
@@ -85,7 +83,6 @@ export function CreateInitiativeDialog({
       name: name.trim(),
       projectIds: projectIds.length > 0 ? projectIds : undefined,
       executionMode,
-      mergeTarget: mergeTarget.trim() || null,
     });
   }
 
@@ -123,20 +120,6 @@ export function CreateInitiativeDialog({
               </SelectContent>
             </Select>
           </div>
-          <div className="space-y-2">
-            <Label htmlFor="merge-target">
-              Merge Target Branch{" "}
-              <span className="text-muted-foreground font-normal">
-                (optional)
-              </span>
-            </Label>
-            <Input
-              id="merge-target"
-              placeholder="e.g. feat/auth"
-              value={mergeTarget}
-              onChange={(e) => setMergeTarget(e.target.value)}
-            />
-          </div>
           <div className="space-y-2">
             <Label>
               Projects{" "}
diff --git a/packages/web/src/components/InitiativeHeader.tsx b/packages/web/src/components/InitiativeHeader.tsx
index adcdcee..af22dec 100644
--- a/packages/web/src/components/InitiativeHeader.tsx
+++ b/packages/web/src/components/InitiativeHeader.tsx
@@ -13,7 +13,7 @@ export interface InitiativeHeaderProps {
     name: string;
     status: string;
     executionMode?: string;
-    mergeTarget?: string | null;
+    branch?: string | null;
   };
   projects?: Array<{ id: string; name: string; url: string }>;
   onBack: () => void;
@@ -74,10 +74,10 @@ export function InitiativeHeader({
               {initiative.executionMode === "yolo" ? "YOLO" : "REVIEW"}
             </Badge>
           )}
-          {initiative.mergeTarget && (
+          {initiative.branch && (
             <Badge variant="outline" className="gap-1 text-[10px] font-mono">
               <GitBranch className="h-3 w-3" />
-              {initiative.mergeTarget}
+              {initiative.branch}
             </Badge>
           )}
           {!editing && projects && projects.length > 0 && (
diff --git a/packages/web/src/components/RegisterProjectDialog.tsx b/packages/web/src/components/RegisterProjectDialog.tsx
index 33291b5..e0b42b9 100644
--- a/packages/web/src/components/RegisterProjectDialog.tsx
+++ b/packages/web/src/components/RegisterProjectDialog.tsx
@@ -24,6 +24,7 @@ export function RegisterProjectDialog({
 }: RegisterProjectDialogProps) {
   const [name, setName] = useState("");
   const [url, setUrl] = useState("");
+  const [defaultBranch, setDefaultBranch] = useState("main");
   const [error, setError] = useState<string | null>(null);
 
   const registerMutation = trpc.registerProject.useMutation({
@@ -40,6 +41,7 @@ export function RegisterProjectDialog({
     if (open) {
       setName("");
       setUrl("");
+      setDefaultBranch("main");
       setError(null);
     }
   }, [open]);
@@ -50,6 +52,7 @@ export function RegisterProjectDialog({
     registerMutation.mutate({
       name: name.trim(),
       url: url.trim(),
+      defaultBranch: defaultBranch.trim() || undefined,
     });
   }
 
@@ -87,6 +90,15 @@ export function RegisterProjectDialog({
               onChange={(e) => setUrl(e.target.value)}
             />
           </div>
+          <div className="space-y-2">
+            <Label htmlFor="default-branch">Default Branch</Label>
+            <Input
+              id="default-branch"
+              placeholder="main"
+              value={defaultBranch}
+              onChange={(e) => setDefaultBranch(e.target.value)}
+            />
+          </div>
           {error && <p className="text-sm text-destructive">{error}</p>}
           <DialogFooter>
             <Button
diff --git a/src/agent/file-io.test.ts b/src/agent/file-io.test.ts
index 622f88c..58ebb39 100644
--- a/src/agent/file-io.test.ts
+++ b/src/agent/file-io.test.ts
@@ -49,7 +49,7 @@ describe('writeInputFiles', () => {
       name: 'Test Initiative',
       status: 'active',
       mergeRequiresApproval: true,
-      mergeTarget: 'main',
+      branch: 'cw/test-initiative',
       executionMode: 'review_per_phase',
       createdAt: new Date('2026-01-01'),
       updatedAt: new Date('2026-01-02'),
diff --git a/src/agent/file-io.ts b/src/agent/file-io.ts
index 83bb981..56764fe 100644
--- a/src/agent/file-io.ts
+++ b/src/agent/file-io.ts
@@ -125,7 +125,7 @@ export function writeInputFiles(options: WriteInputFilesOptions): void {
         name: ini.name,
         status: ini.status,
         mergeRequiresApproval: ini.mergeRequiresApproval,
-        mergeTarget: ini.mergeTarget,
+        branch: ini.branch,
       },
       '',
     );
diff --git a/src/agent/manager.ts b/src/agent/manager.ts
index a234907..ad28e64 100644
--- a/src/agent/manager.ts
+++ b/src/agent/manager.ts
@@ -222,7 +222,7 @@ export class MultiProviderAgentManager implements AgentManager {
     let agentCwd: string;
     if (initiativeId) {
       log.debug({ alias, initiativeId, baseBranch, branchName }, 'creating initiative-based worktrees');
-      agentCwd = await this.processManager.createProjectWorktrees(alias, initiativeId, baseBranch ?? 'main', branchName);
+      agentCwd = await this.processManager.createProjectWorktrees(alias, initiativeId, baseBranch, branchName);
 
       // Log projects linked to the initiative
       const projects = await this.projectRepository.findProjectsByInitiativeId(initiativeId);
diff --git a/src/agent/process-manager.ts b/src/agent/process-manager.ts
index 4c8df5e..e0b0707 100644
--- a/src/agent/process-manager.ts
+++ b/src/agent/process-manager.ts
@@ -54,7 +54,7 @@ export class ProcessManager {
   async createProjectWorktrees(
     alias: string,
     initiativeId: string,
-    baseBranch: string = 'main',
+    baseBranch?: string,
     branchName?: string,
   ): Promise<string> {
     const projects = await this.projectRepository.findProjectsByInitiativeId(initiativeId);
@@ -78,7 +78,8 @@ export class ProcessManager {
     for (const project of projects) {
       const clonePath = await ensureProjectClone(project, this.workspaceRoot);
       const worktreeManager = new SimpleGitWorktreeManager(clonePath, undefined, agentWorkdir);
-      const worktree = await worktreeManager.create(project.name, branchName ?? `agent/${alias}`, baseBranch);
+      const effectiveBaseBranch = baseBranch ?? project.defaultBranch;
+      const worktree = await worktreeManager.create(project.name, branchName ?? `agent/${alias}`, effectiveBaseBranch);
       const worktreePath = worktree.path;
       const pathExists = existsSync(worktreePath);
 
diff --git a/src/dispatch/manager.ts b/src/dispatch/manager.ts
index 27cb923..ff6cbbd 100644
--- a/src/dispatch/manager.ts
+++ b/src/dispatch/manager.ts
@@ -22,7 +22,7 @@ import type { InitiativeRepository } from '../db/repositories/initiative-reposit
 import type { PhaseRepository } from '../db/repositories/phase-repository.js';
 import type { Task } from '../db/schema.js';
 import type { DispatchManager, QueuedTask, DispatchResult } from './types.js';
-import { initiativeBranchName, phaseBranchName, taskBranchName } from '../git/branch-naming.js';
+import { phaseBranchName, taskBranchName, isPlanningCategory, generateInitiativeBranch } from '../git/branch-naming.js';
 import { createModuleLogger } from '../logger/index.js';
 
 const log = createModuleLogger('dispatch');
@@ -327,20 +327,32 @@ export class DefaultDispatchManager implements DispatchManager {
     let baseBranch: string | undefined;
     let branchName: string | undefined;
 
-    if (task.phaseId && task.initiativeId && this.initiativeRepository && this.phaseRepository) {
+    if (task.initiativeId && this.initiativeRepository) {
       try {
-        const initiative = await this.initiativeRepository.findById(task.initiativeId);
-        const phase = await this.phaseRepository.findById(task.phaseId);
-        if (initiative?.mergeTarget && phase) {
-          const initBranch = initiativeBranchName(initiative.mergeTarget);
+        if (isPlanningCategory(task.category)) {
+          // Planning tasks run on project default branches — no initiative branch needed.
+          // baseBranch and branchName remain undefined; ProcessManager uses per-project defaults.
+        } else if (task.phaseId && this.phaseRepository) {
+          // Execution task — ensure initiative has a branch
+          const initiative = await this.initiativeRepository.findById(task.initiativeId);
+          if (initiative) {
+            let initBranch = initiative.branch;
+            if (!initBranch) {
+              initBranch = generateInitiativeBranch(initiative.name);
+              await this.initiativeRepository.update(initiative.id, { branch: initBranch });
+            }
 
-          if (task.category === 'merge') {
-            // Merge tasks work directly on the phase branch
-            baseBranch = initBranch;
-            branchName = phaseBranchName(initBranch, phase.name);
-          } else {
-            baseBranch = phaseBranchName(initBranch, phase.name);
-            branchName = taskBranchName(initBranch, task.id);
+            const phase = await this.phaseRepository.findById(task.phaseId);
+            if (phase) {
+              if (task.category === 'merge') {
+                // Merge tasks work directly on the phase branch
+                baseBranch = initBranch;
+                branchName = phaseBranchName(initBranch, phase.name);
+              } else {
+                baseBranch = phaseBranchName(initBranch, phase.name);
+                branchName = taskBranchName(initBranch, task.id);
+              }
+            }
           }
         }
       } catch {
diff --git a/src/dispatch/phase-manager.ts b/src/dispatch/phase-manager.ts
index b922e3f..112c921 100644
--- a/src/dispatch/phase-manager.ts
+++ b/src/dispatch/phase-manager.ts
@@ -20,7 +20,7 @@ import type { InitiativeRepository } from '../db/repositories/initiative-reposit
 import type { ProjectRepository } from '../db/repositories/project-repository.js';
 import type { BranchManager } from '../git/branch-manager.js';
 import type { PhaseDispatchManager, DispatchManager, QueuedPhase, PhaseDispatchResult } from './types.js';
-import { initiativeBranchName, phaseBranchName } from '../git/branch-naming.js';
+import { phaseBranchName } from '../git/branch-naming.js';
 import { ensureProjectClone } from '../git/project-clones.js';
 import { createModuleLogger } from '../logger/index.js';
 
@@ -172,13 +172,13 @@ export class DefaultPhaseDispatchManager implements PhaseDispatchManager {
     if (this.initiativeRepository && this.projectRepository && this.branchManager && this.workspaceRoot) {
       try {
         const initiative = await this.initiativeRepository.findById(phase.initiativeId);
-        if (initiative?.mergeTarget) {
-          const initBranch = initiativeBranchName(initiative.mergeTarget);
+        if (initiative?.branch) {
+          const initBranch = initiative.branch;
           const phBranch = phaseBranchName(initBranch, phase.name);
           const projects = await this.projectRepository.findProjectsByInitiativeId(phase.initiativeId);
           for (const project of projects) {
             const clonePath = await ensureProjectClone(project, this.workspaceRoot);
-            await this.branchManager.ensureBranch(clonePath, initBranch, 'main');
+            await this.branchManager.ensureBranch(clonePath, initBranch, project.defaultBranch);
             await this.branchManager.ensureBranch(clonePath, phBranch, initBranch);
           }
           log.info({ phaseId: nextPhase.phaseId, phBranch, initBranch }, 'phase branch created');
diff --git a/src/execution/orchestrator.ts b/src/execution/orchestrator.ts
index 0ddf61d..19666f6 100644
--- a/src/execution/orchestrator.ts
+++ b/src/execution/orchestrator.ts
@@ -19,7 +19,7 @@ import type { InitiativeRepository } from '../db/repositories/initiative-reposit
 import type { ProjectRepository } from '../db/repositories/project-repository.js';
 import type { PhaseDispatchManager } from '../dispatch/types.js';
 import type { ConflictResolutionService } from '../coordination/conflict-resolution-service.js';
-import { initiativeBranchName, phaseBranchName, taskBranchName } from '../git/branch-naming.js';
+import { phaseBranchName, taskBranchName } from '../git/branch-naming.js';
 import { ensureProjectClone } from '../git/project-clones.js';
 import { createModuleLogger } from '../logger/index.js';
 
@@ -64,7 +64,7 @@ export class ExecutionOrchestrator {
     if (!task?.phaseId || !task.initiativeId) return;
 
     const initiative = await this.initiativeRepository.findById(task.initiativeId);
-    if (!initiative?.mergeTarget) return;
+    if (!initiative?.branch) return;
 
     const phase = await this.phaseRepository.findById(task.phaseId);
     if (!phase) return;
@@ -72,7 +72,7 @@ export class ExecutionOrchestrator {
     // Skip merge tasks — they already work on the phase branch directly
     if (task.category === 'merge') return;
 
-    const initBranch = initiativeBranchName(initiative.mergeTarget);
+    const initBranch = initiative.branch;
     const phBranch = phaseBranchName(initBranch, phase.name);
     const tBranch = taskBranchName(initBranch, task.id);
 
@@ -149,7 +149,7 @@ export class ExecutionOrchestrator {
     if (!phase) return;
 
     const initiative = await this.initiativeRepository.findById(phase.initiativeId);
-    if (!initiative?.mergeTarget) return;
+    if (!initiative?.branch) return;
 
     if (initiative.executionMode === 'yolo') {
       await this.mergePhaseIntoInitiative(phaseId);
@@ -178,9 +178,9 @@ export class ExecutionOrchestrator {
     if (!phase) return;
 
     const initiative = await this.initiativeRepository.findById(phase.initiativeId);
-    if (!initiative?.mergeTarget) return;
+    if (!initiative?.branch) return;
 
-    const initBranch = initiativeBranchName(initiative.mergeTarget);
+    const initBranch = initiative.branch;
     const phBranch = phaseBranchName(initBranch, phase.name);
 
     const projects = await this.projectRepository.findProjectsByInitiativeId(phase.initiativeId);
diff --git a/src/git/branch-naming.ts b/src/git/branch-naming.ts
index 31aea55..3981859 100644
--- a/src/git/branch-naming.ts
+++ b/src/git/branch-naming.ts
@@ -5,6 +5,23 @@
  * in the initiative → phase → task branch hierarchy.
  */
 
+/**
+ * Task categories that run on the project's default branch (no initiative branch needed).
+ */
+export const PLANNING_CATEGORIES = ['research', 'discuss', 'plan', 'detail', 'refine'] as const;
+
+/**
+ * Task categories that require an initiative branch.
+ */
+export const EXECUTION_CATEGORIES = ['execute', 'verify', 'merge', 'review'] as const;
+
+/**
+ * Check if a task category is a planning category (runs on default branch).
+ */
+export function isPlanningCategory(category: string): boolean {
+  return (PLANNING_CATEGORIES as readonly string[]).includes(category);
+}
+
 /**
  * Convert a name to a URL/branch-safe slug.
  * Lowercase, replace non-alphanumeric runs with single hyphens, trim hyphens.
@@ -17,11 +34,19 @@ export function slugify(name: string): string {
 }
 
 /**
- * Compute the initiative branch name.
- * Returns the mergeTarget as-is (it's already a branch name), or 'main' if unset.
+ * Generate an initiative branch name from the initiative name.
+ * Format: `cw/<slugified-name>`
  */
-export function initiativeBranchName(mergeTarget: string | null): string {
-  return mergeTarget ?? 'main';
+export function generateInitiativeBranch(name: string): string {
+  return `cw/${slugify(name)}`;
+}
+
+/**
+ * Compute the initiative branch name.
+ * Returns the branch as-is if set, or null if unset.
+ */
+export function initiativeBranchName(branch: string | null): string | null {
+  return branch;
 }
 
 /**
diff --git a/src/trpc/routers/initiative.ts b/src/trpc/routers/initiative.ts
index 2ed4a3d..6e0b68d 100644
--- a/src/trpc/routers/initiative.ts
+++ b/src/trpc/routers/initiative.ts
@@ -14,7 +14,6 @@ export function initiativeProcedures(publicProcedure: ProcedureBuilder) {
         name: z.string().min(1),
         projectIds: z.array(z.string().min(1)).min(1).optional(),
         executionMode: z.enum(['yolo', 'review_per_phase']).optional(),
-        mergeTarget: z.string().nullable().optional(),
       }))
       .mutation(async ({ ctx, input }) => {
         const repo = requireInitiativeRepository(ctx);
@@ -36,7 +35,6 @@ export function initiativeProcedures(publicProcedure: ProcedureBuilder) {
           name: input.name,
           status: 'active',
           ...(input.executionMode && { executionMode: input.executionMode }),
-          ...(input.mergeTarget !== undefined && { mergeTarget: input.mergeTarget }),
         });
 
         if (input.projectIds && input.projectIds.length > 0) {
@@ -102,11 +100,10 @@ export function initiativeProcedures(publicProcedure: ProcedureBuilder) {
         return repo.update(id, data);
       }),
 
-    updateInitiativeMergeConfig: publicProcedure
+    updateInitiativeConfig: publicProcedure
       .input(z.object({
         initiativeId: z.string().min(1),
         mergeRequiresApproval: z.boolean().optional(),
-        mergeTarget: z.string().nullable().optional(),
         executionMode: z.enum(['yolo', 'review_per_phase']).optional(),
       }))
       .mutation(async ({ ctx, input }) => {
diff --git a/src/trpc/routers/project.ts b/src/trpc/routers/project.ts
index 7898306..f7431d5 100644
--- a/src/trpc/routers/project.ts
+++ b/src/trpc/routers/project.ts
@@ -17,13 +17,18 @@ export function projectProcedures(publicProcedure: ProcedureBuilder) {
       .input(z.object({
         name: z.string().min(1),
         url: z.string().min(1),
+        defaultBranch: z.string().min(1).optional(),
       }))
       .mutation(async ({ ctx, input }) => {
         const repo = requireProjectRepository(ctx);
 
         let project;
         try {
-          project = await repo.create({ name: input.name, url: input.url });
+          project = await repo.create({
+            name: input.name,
+            url: input.url,
+            ...(input.defaultBranch && { defaultBranch: input.defaultBranch }),
+          });
         } catch (error) {
           const msg = (error as Error).message;
           if (msg.includes('UNIQUE') || msg.includes('unique')) {