There are three possible reasons for the tips of the leaves of the Wollemi Pine to go brown.• Insufficient water, which causes the ends of the branches to die back • An incorrect pH balance of the soil or growing media • Insufficient fertiliser or too much fertiliser. Always ensure controlled release fertiliser is evenly placed around the tree and not in contact with the stem Note that a yellow tinge on the very tips of the leaflets is a normal and common occurrence in both the wild and cultivated Wollemi Pines. Severe cases of leaf tipping are most likely induced by one of the three factors described above. The best advice to on these occasions is: Re-pot either into a bigger pot or one of the same size. pH should not be a problem if ericaceous compost is used. In a high calcium water area (hard water area like South East England) it would be best to water with rain water. In most cases the problem will correct itself with good care techniques.