Cabbages! Gardens were called kálgardr and kålhave which be translated as "cabbage garden" or "kale garden". The plants were probably much like modern flat kale or collards (heading cabbages are only known from the 13th century and later). The other main garden food plants were beans (broad beans, Vicia faba), peas, onions, leeks, and fruit trees (apples, damsons, cherries). Other food plants included a variety of greens such as orach, angelica and ground elder (AKA bishop's weed, Aegopodium podagraria), root vegetables such as carrots and radishes, and other plants such as grapes, garlic, strawberries, and walnuts.

A range of herbs were grown. Many of these were dual-use foods and medicines (but also note that diet was an important part of early medicine, and medicinal aspects of common foods were considered by doctors). Herbs and medicines include coriander, mint, thyme, sorrel, wormwood, St John's wort, opium, and henbane (henbane is too toxic for food use, and would have been purely medicinal).

A third class of garden plants are dyes. Common dye plants included woad and madder.

We have no good evidence for purely ornamental plants in Viking gardens, but it's possible that flowers such as daisies were grown. Of course, many of the food plants can be ornamental, and aesthetics may well have played a role in the Viking garden.

There are plants that were eaten, but we don't know whether they were grown in gardens or just collected from the wild (e.g., nettles).

For southern Scandinavia, and discussion of the kinds of evidence we have, see:

• Pernille Rohde Sloth, Ulla Lund Hansen & Sabine Karg (2012), "Viking Age garden plants from southern Scandinavia – diversity, taphonomy and cultural aspects", Danish Journal of Archaeology, 1:1, 27-38, https://doi.org/10.1080/21662282.2012.750445

The Ribe VikingeCenter website has information about Viking gardens (and field crops): https://www.ribevikingecenter.dk/en/learn-more/manor-farm-garden.aspx