Kelda seeds are obtained during the Forgettable Tale of a Drunken Dwarf quest. There are four of them and must be obtained from the various friends of the Drunken Dwarf with one of them received from the dwarf himself. They must be planted in the farming patch in Keldagrim, east of the bank, to grow Kelda hops, which are used to brew Kelda stout.
This hop takes only 20 minutes to grow and does not need to be watered/composted. While waiting for the Kelda seeds to grow you may walk through town or run a errand for the gardener. Planting these seeds give 9 experience.