Hostas come in many shapes and sizes ranging from mini to very large and have different growing habits that are genetic, depending on the variety (cultivar).

When looking for upright hostas try this link...Hosta Lists

This link Hosta Library is the home to the Hosta Lists, thousands of Hosta pictures, articles, etc and is a wonderful resource.

If your friend is looking for taller growing hostas to add to her mix, she will surely find many beautiful ones to choose from in the links. I can recommend two that I have and they are 'Sagae' and 'Krossa Regal'....classic hostas that are very popular and widely available.

Yes. I know there are wise varieties and some large, medium, small, etc....some take longer to grow, etc.. Between she and I we have over 250 varieties. Funny you mention Sagae and Krossa Regal. Those are 2 she has that are beautiful, she's had Sagae 4 years and it is loaded with leaves., but doesn't get height....neither does Victory, Liberty, Big Daddy... Her Emperess Wu grew huge, this year (was small last year and has only had it 3 years). She doesn't have an issue with that type of Hosta that gets full and leaf size gets big.

Sooo many variables. Is she planting them too deep? I have had problems with a couple that I planted too deep; they were sort of flatter than usual. After moving and replanting, less of a problem. If the heavy clay is a problem you may have to dig entire beds and add compost, pinebark or turface. I prefer compost as its free from a community compost site. Ammending a little at a time may not be enough. IDK, extra water helps too. With clay water soaks in slower so long and slow for watering. Good luck on figuring this one out.

What height is she looking for? My tallest hosta is 29 inches tall and 66 inches across, not counting the flower stalks. I like to plant medium and small hostas next to the larger ones to contrast the difference in size. Perhaps she can add some other plants such as solomon's seal, ferns, etc for contrast in height and texture. As long as her hostas are healthy I wouldn't worry about size.

Northern Minnesota by Lake Superior. She, for some reason can get on the library, but not forum. Knew about the lifting of them, but that hasn't helped. They aren't like stunted or anything bad, she's just been trying to look it up and ask around if there is a reason we're not aware of..like a defiency into be soil. She does t dig her hostas strait into the clay, she adds a good soil, but just was wondering if the surrounding soil could be lacking a mineral or something. I guess she will just be happy with how they do and hope they decide to getting more height

Ask her to try going to Houzz.com, then clicking on "Stories and Advice", then clicking on "Garden Forums", then clicking on "Hosta". She will have to set up a Houzz account if she wants to post on the forum, but otherwise she can view all the posts.

How tall is her 4 year old Sagae? It takes longer than that to get mature sized leaves and height. Small and medium hostas don't get very high, but rather spread outward.

Yup, we need photos.

-Babka

They are planted too deep.

They are in too much sun.

They are not getting enough water.

Those are your three choices really.....