I've never had columbines but have had heucheras in both full shade, partial shade and full sun. The ones in full sun have definitely done the best but they are planted around our pond where there is more moisture. The heucheras in shade never flourished like the ones in full sun.

Both the native species of Heuchera (americana and sanguinea) are common to more or less open areas or woodland verges, so adaptable to sun to partial shade. The modern hybrids with intense foliage coloring are somewhat variable as well - generally, the more vivid the leaf color, the more sun is required to maintain that color. The exceptions are the cultivars with very pale color, like the golds or chartreuse or those with heavy white variegation. They are susceptible to scorch or sunburn and fair better in part shade. All heucheras prefer a rich organic soil and an even source of moisture. And some of the hybrids are just not very robust plants and tend to dwindle wherever they are planted and are not very long-lived. Also, some are grown primarily for foliage effect and flowering will be minimal and the flowers themselves inconspicuous.

IME, columbines will flourish and bloom anywhere, from full shade to full sun. Again, some of the native species are woodland plants and full sun can be a bit harsh unless given a rich, moisture retentive soil.

Hi,

I have two types of heuchera, Palace Purple (purple foliage)and Bressingham (green foliage, scarlet flowers). Palace purple is doing well this year under a canopy of maples with quite thick shade. The Bressinghams are coming back quite decently despite being planted in amended clay beds. They are in sun/ part sun.

I have a columbines (cultivars) but they have always been in full sun, and done very well. Never tried them in shade.

Hope this helps.