Cognitive behavioral therapy and pharmacological intervention with selective serotonin reuptake inhibitors (SSRIs) have been proven to be effective treatments for anxiety in children, and a combination of the two has emerged as the gold standard for treating anxiety disorders. 
Many parents instinctively have concerns about medicating their children, leading them to investigate the realm of alternative and natural remedies instead. Add to this that the Food and Drug Administration (FDA) issued a warning to let consumers and clinicians know that antidepressants increase the risk of suicidal thoughts and behavior in young people , and it is hardly surprising that you are hoping that natural remedies and supplements can help your anxious child.
St Johns Wort And Valerian Are Safe And Effective Natural Anxiety Treatments For Children
One study tested the efficacy of a herbal treatment that combined St John's Wort, valerian root, and passionflower on a small sample of children suffering from anxiety, depression, and sleeping problems (note that nightmares and night terrors point to anxiety in children). Not only did the study indicate that symptoms improved for the vast majority of children, to the point where they were no longer suffering from anxiety, sleeping problems and depression or had only mild complaints, it also found that the treatment was well-tolerated. 
St Johns Wort, one of the most extensively studied medicinal herbs, has been established as an effective treatment for mild to moderate depression in adults to the point where it can now be considered a mainstream medical treatment. While its mechanism of action is still not completely clear, it appears to function very much like the SSRI class of antidepressants, by increasing the availability of serotonin, dopamine and noradrenaline.  The finding that it is well tolerated by children is thus good news.
Kava Kava May Reduce Anxiety, But Is It Safe?
There is some evidence that kava kava, a member of the pepper family, helps treat generalized anxiety disorder. Furthermore, this remedy is not habit-forming in therapeutic doses.  However, as kava kava has also been found to induce liver toxicity in rare cases, when the herbal anxiety remedy is taken over long periods of time , some countries are now advising consumers against its use . This makes kava kava an unsuitable anxiety remedy for children.
Omega 3 Fatty Acids Work For Depression But Not Anxiety?
A small study of children between the ages of six and 12 revealed that supplementation with Omega 3 fatty acids significantly reduced symptoms of depression in the majority of the test group.  As anxiety and depression are often comorbid (existing at the same time), parents may hope that Omega 3 fatty acids can help reduce their child's symptoms. While research suggests that Omega 3 fatty acids do not have an anti-anxiety effect , Omega 3 is nonetheless a safe nutritional supplement in children and there is no danger in adding it to your child's daily routine.
Herbal Anxiety Treatments For Children: What Research Shows Doesn't Work
Bach flower remedies represent a popular self-help option for people suffering from a wide range of mood troubles. If your child is suffering from anxiety, you may well find that someone recommends you try Bach flower remedies — a separate line is available especially for children. Research has not been able to show that these flower remedies are more effective than placebo use, however. 
There is likewise no evidence that ginger, gotu kola, lemongrass, or licorice are effective at reducing anxiety . Homeopathy is popular among anxiety sufferers, but there is, again, insufficient evidence that its use is effective. 
Could Unproved And Disproved Anxiety Remedies Still Work? A Quick Look At The Placebo Effect
The fact that placebos have been shown to produce a degree of improvement in people suffering from anxiety means they may be a particularly useful addition to a parent's tool box. Your clingy child with separation anxiety, mild social phobia, generalized anxiety disorder, or specific phobias, not knowing that the efficacy of particular alternative anxiety remedies is not supported by scientific evidence, may find some symptom relief. As long as the treatment you were hoping to try is safe for use in children — and you are still willing to consider cognitive behavioral therapy in addition to the unproven natural remedy or placebo treatment — there is no harm in seeing what happens.