Right now, through January 21, Prairie Nursery in Wisconsin is offering free shipping on spring orders. This is a significant savings: shipping charges can easily reach 20 percent or more of the cost of your order. Order now and specify your spring delivery date (the third week in April is usually a great time to get plants in the ground in our area). But be sure that the plants you order are native to this area–Prairie Nursery sells midwestern natives, and the range of some does not extend to this area. Before ordering, check the USDA Plant Database or the Lady Bird Johnson Wildflower Center to be sure.
A little closer is the Native Plant Center at Westchester Community College, which offers an annual spring plant sale. Order your plants now and pick them up at the center in late April. This sale includes fewer species than Prairie Nursery offers, but it offers some hard-to-find plants, including Pachysandra procumbens.