Mock orange ideally in the autumn and the rest in Spring. But the mock orange can be planted any time if its container grown.

if container grown they can be planted anytime unless the ground is frozen or waterlogged.
if you haven't bought them yet then wait until spring. If you have then then get them in now. water well. make the planting hole at least half as big again as the root ball. gently tease out any congested roots so they grow out into the soil.