Best way to spawn objects randomly on only x-axis on Mobile

Putting it simply...this is currently what I have:

 public GameObject CollectGO;

 public int depth;
 public int maxDepth;

 void Start()
 {
     if (depth < maxDepth)
     {
         StartCoroutine("Gen");
     }
 }

 void Initialize(CollGO parent)
 {
     transform.parent = parent.transform;

     maxDepth = parent.maxDepth;
     CollectGO = Resources.Load ("Carrot") as GameObject;
     transform.localPosition = Vector2.right * (Random.Range (4f, 25f));
     Instantiate (CollectGO, transform.position, transform.rotation);


 }



 IEnumerator Gen()
 {
     yield return new WaitForSeconds (0.36f);
     new GameObject ("CollGO Child").AddComponent<CollGO> ().Initialize (this);
 }

Which I've found is quite slow:

So I'm wondering (As I'm new to Mobile Development and unity development as a whole) if there is a faster or more efficient way of spawning the objects (Mainly), and randomizing them on the X-Axis.

Cheerio and Happy New Yearish.