Loosen the garden soil in early spring to help the soil warm sooner. Work the soil to a depth of 8 to 10 inches with a garden spade.
Amend the soil with a 1- to 2-inch layer of compost, to help promote good drainage. Work it in well with your spade.
Spread a slow-release granular fertilizer with high nitrogen content onto the amended soil. Rake it into the soil evenly.
Dig a hole for each citronella geranium plant that is the same depth as its nursery pot.
Remove the citronella geranium from the nursery pot. Break up the exterior of the root ball gently with your hands if the plant appears root-bound. Set the geranium carefully into the planting hole.
Backfill the hole with amended garden soil until it is level with the landscape. Tamp the soil lightly with your hand to eliminate air pockets.
Water the citronella geraniums directly after planting. Then water them adequately once per week, preferably in the morning, to prevent wilting.