For years I have wanted to create a lemon garden, every since I read an article about one in the magazine "Herb Companion" in the mid-1990s. I saved that article for years and had it in my file of 'things I want to do" but guess I lost track of it somewhere along the way.

I never have created that lemon garden, but do sprinkle many lemon-scented plants around my vegetable garden and its accompanying cottage-style border.

Here are a few of my favorites that you might consider, in addition to the ones you already have on your list.

Lemon Thyme (Thymus x citriodorus)

Golden Lemon Thyme (Thymus x citriodorus 'Golden King')

Lemon Verbena (Aloysia triphylla)--gets pretty large by the end of the growing season, almost shrubby

Lemon Mint (Monarda citriodora)

Marigold 'Lemon Gem' (not really as lemon-scented as they want you to think it is, at least not in my soil)

Lemon Basil 'Mrs. Burns' has larger leaves and (to me) a better scent than ordinary lemon basil.

Lemon Lily (Lilium parryi) I haven't grown this one but some people say it has a strong lemon scent and some say it doesn't. I suspect more than one variety is being sold under this name.

Among the lemon-scented geraniums, you will find many named varieties available. Some have regular foliage and some are variegated. Some have rose-colored flowers. None of them are reliably hardy in our climate.

Many roses are available that are described as having a lemon fragrance, although I find their fragrance to be a rose-lemon blend, and not a pure lemon aroma. These include the David Austin English Rose "Heritage" as well as the fairly easy-to-find "Angel Face". Hopefully some of the people on this forum who grow lots of roses can give you the names of some more lemon-scented ones.

Lemon balm is perennial in my garden, and lemon basil usually reseeds itself (everywhere).

I have two yellow tall bearded irises blooming right now and I sniffed them yesterday to see if they had a smell and both of them smell like lemons to me. I got them from my brother-in-law last year, so I don't know their names.
Sometimes in the plant description in a catalog, they will mention the lemon scent.

Susie

I thought of some more. Some, like the common sorrel, are easy to find. Others are sort of obscure, but all have some sort of lemony fragrance.

Lemon Bottlebrush (Callistemon citrinus)
Lemon Myrtle (Backhousia citriodora)
Lemon Eucalyptus (Eucalyptus citriodora) aka Lemon Gum Tree
Tangerine Southernwood (Artemisia abrotanum'Tangerine') (Why it is not called Lemon Southernwood I do not know.)
Lemon Santolina or Lavendar Cotton, 'Lemon Queen' (Santolina chamaecyparissus)
Lemon Tea Tree (Leptospermum petersonii)
Common Sorrel (Rumex acetosa)
French Sorrel (Rumex scutatus)
Mexican Giant Hyssop (Agastache mexicana)
Pepper 'Lemon Drop' -- it is the peppers themselves that have the lemony-peppery scent when cut. If the foliage or flowers have a lemony scent, I can't recall that I ever noticed it.
African Winter Savory (Saturjea biflora)
Winter Savory (Saturjea montana/hortensis)