Windmill palms are slow-growing trees that require little maintenance. They are an excellent choice for a houseplant because they grow well in containers, and their fan-shaped fronds add a tropical feel to any area. Container-grown windmill palms can reach a height of 7 to 10 feet. You should transplant your palm in the spring every 2 to 3 years -- after the roots start to emerge from the bottom of the pot or the container starts to split open.
Choose a new container for your windmill palm, one size larger than its current pot. Purchase a container sturdy enough to support the top-heavy palm with drainage holes in the bottom.
Purchase potting soil at a local greenhouse or nursery. Container-grown windmill palms require a good-draining soil that provides sufficient aeration for the root ball. Alternatively, mix your own soil for your windmill palm, using two-parts peat moss, two-parts pine bark and one-part sand.
Gently tip your windmill palm on its side so as not to damage any fronds. Grasp the trunk and roll the container back and forth to loosen the root ball. With one hand on the trunk and one hand on the lip of the container, slide the root ball out of the pot. Handle the root ball gently to avoid causing damage.
Use mycorrhizal fungi, an additive that you can purchase at your local garden centre or nursery, to dust the root ball, following the package instructions. Mychorrizal fungi aids in minimising the palm's transplant shock. The fungi develops a symbiotic relationship with the palm, allowing the roots to bond to the soil and more easily extract nutrients from it.
Fill the new container until 1/3-full with potting soil. Place the palm's root ball in the centre of the container. Adjust its position until the palm is standing upright in the centre of the pot.
Pour soil into the container around the root ball until it is halfway full. Water the soil with a garden hose or watering can to compact the soil.
Add more soil to the container until the root ball is covered. Pat down the soil to firm it around the palm. Continue to add soil until the soil level is 2 to 3 inches below the top of the container. This space will act as a reservoir when you water the palm.
Water the potted palm thoroughly until water is running from the drainage holes at the bottom. Water your palm every day for the next 3 to 4 weeks. After 4 weeks, begin watering the palm only when the top 2 inches of soil are dry. The soil must remain moist but not over-saturated.
Place your newly potted palm in a warm area that receives full, direct sunlight. Your palm will need at least 6 hours of sunlight, but 8 to 10 hours are preferred. Palms grow best in temperatures of 23.9 to 35 degrees Celsius. Feed your palm with a time-release fertiliser in the spring and fall.