Monstera Leaves Growing Sideways. If you have been fertilizing once a month nutrient deficiency is an unlikely cause. Monstera deliciosa usually grows vertically on just a few stems when its young but starts to grow sideways when it gets older and heavier.
Im an old gal who still loves playing in the dirt. Your Monstera loves bright light but not the rays of the sun. Playing in the dirt is my therapy.
Keep in mind that after a leaf develops it will not change.
Go up in container size each year for the first few years so the Monstera can continue growing. Im an old gal who still loves playing in the dirt. Your houseplant actually needs a lot of light to grow those big beautiful leaves you really admire. Set the roots into the container.