One of the many preparations that Gatsby arranges to beautify Nick's house, which could be rather insulting for Nick if you think about it, is to organise for his gardener to come over and mow the lawn. In addition, with the flowers that arrive and other little additions organised by Gatsby, we see how determined Gatsby is to create the right impression of extravagant wealth and perfection that he wishes to project to Daisy. Let us remember, before we judge him too harshly, that this is their first meeting since before he left to go to war and before Daisy married Tom, so he wants to make sure that the first impressions that Daisy have of him now that he has transformed into Jay Gatsby count. Note how the gardener is introduced in chapter five:
The day agreed upon was pouring rain. At eleven o'clock a man in a raincoat, dragging a lawn-mower, tapped at my front door and said that Mr. Gatsby had sent him over to cut my grass.
So it is that Gatsby readies the stage for his much-longed for meeting with his, as he belives, true love.