Two weeks ago I planted 2 jacaranda saplings in 2 different areas in soil that is clayey in texture.

One area I notice tends to stay wet longer. the jacaranda in this section appears to be doing fine. The other section looks somewhat dry. The jacaranda in this section I noticed have begun to show signs of burn at the tip of the leaflets.

These saplings have been deeply watered every 5 or so days.
I'm wondering what could be causing the leaves to show sign of burn. Could the problems be lack of water, too much water or poor drainage?

If leaf tip burn is due to poor drainage, will removing the sapling and lining the bottom with a couple inches of gravel be of any value?

thanks,

Jacaranda often has a spreading and shallow root system. If, when you planted, you used a broad and fairly shallow 'bowl' shape and planted out on top of a gentle mound of good soil mixed with aged compost and backfilled with a similar mix, then water can drain away. The compost helps to retain moisture for the plant, keeps the area loose enough for young foraging roots, and lets vital air through as well.

As the plant has not been in the ground for long enough to really settle you could unearth it to see what is happening in the root zone.

Gravel in the bottom of the hole doesn't help. However, sharp grit - about 5mm diameter - mixed through the soil/compost can encourage roots to spread out. Not 'heaps'; half to one bucket to about ten buckets of your soil mix.

The other possible is that the Jacaranda is starting to wind down for winter. Some of them drop their leaves over winter and early spring prior to flowering.

Also have a quick think back over your temperature range recently: any chilly mornings that might have given a touch of frost damage? They're not fond of frost - particularly when young.