Q. When is the best time to transplant a Joshua tree? A. The best time is in mid to late spring but could be done in summer. The worst times are fall and early winter months. Stay away from these time periods for planting Joshua. Joshua tree rootball             The biggest mistakes made on planting Joshua is watering too often. Joshua’s are not the easiest plants to transplant mostly because the roots taken when harvested from the Desert are not very extensive.             Start with a smaller plant and stake it to keep the roots from moving. Plant them the same depth as they were when they were harvested.             Amend the existing soil with about 25% compost at the time of planting. They will benefit from improved soils at the time of planting. Water at the time of planting thoroughly and then hold off for at least three weeks before watering again.             Water no more than about every three weeks in summer. Less often in cooler and colder weather.