Transplanting plants from pots to the garden is common, even if you live in an area with sandy soil. Many gardeners, however, incorporate 4 to 6 inches of peat moss, topsoil or compost to the top 12 inches to create more ideal soil conditions, especially for plants that are heavy drinkers. This is not necessary, though; you can plant your potted plants directly into the sandy soil. However, if you do this, you must water them more often than if they were planted in heavier soil conditions.
Water your potted plants thoroughly--until it seeps out the drainage holes--the day before you move them into the sandy soil. The plants will be well hydrated for the move, which is often stressful for plants.
Take the plants out of their pots by tapping on the sides, if necessary. Keep the soil around the roots.
Dig holes in the new planting site and provide enough space for their mature size, which varies among plants. The holes should be two times as wide and the same depth as their current pots.
Set the plants into the holes. Again, keep their old soil intact.
Backfill the sandy soil around the plants to fill in the space and lightly pack it down with the bottoms of your hands.
Water your plants once or twice a day with 1 inch of water, especially during the hot summer months. Water in the mornings and evenings when less evaporation occurs.
Add a 2-inch layer of mulch around the plants. Sandy soil dries out quickly and this will help retain the much needed moisture. Use an organic mulch such as bark or wood chips.