Complex sentence: Proclaiming them the most beautiful trees he had ever seen, he returned with seeds, and getting assurance from a friend of his at the Department of Agriculture that the trees would do well in California, had his brother Frederick nurser them at the Altadena ranch.
Split into simpler sentences: Proclaiming them the most beautiful trees he had ever seen, he returned with seeds. With assurance from a friend of his at the Department of Agriculture that the trees would do well in California, John had his brother Frederick raise them at the Altadena ranch.