Have you done a soil sample? The ladino clovers need a good quality top soil of about 8-12 inches. Different folks use the spring vs fall planting methods. With the fall planting you should get a chance for the plant to root before the stress of summer heat. With the spring you get some results the same year.
We still advise using the alamac and other weather advisory information sites. If the seedling is exposed to extreme heat or cold before 30-60 days there is a good chance of failure.