Q.Desert Willows
I.have grown them from seed in my house. They germinate well. The leaves are turning brown usually from top down but some bottom up. They are in pots in house still. They are not growing well.

Certified GKH Gardening Expert
They probably aren't getting enough light. They need full sun. Also be sure the pot is deep enough for the growing roots and the soil is well draining. Let the soil dry out between waterings. These articles should help:
https://www.gardeningknowhow.com/ornamental/trees/desert-willow/desert-willow-seed-germination.htm
https://www.gardeningknowhow.com/ornamental/trees/desert-willow/caring-for-desert-willow-trees.htm