All you need to grow a coconut (Cocos nucifera) from seed are heat, humidity and a fresh, ripe coconut. While it will be a few years before you harvest coconuts, the planting and growing process take only minimal effort. Unless you have a large greenhouse that stays warm and humid, growing a coconut tree to maturity is best suited for the frost-free tropical and subtropical climates of U.S. Department of Agriculture plant hardiness zones 10 through 11.
Know Your Nut
Select a mature coconut for planting, ideally one that has fallen naturally from the tree. Coconuts from the store are often de-husked, but for planting you want one with the husk intact. The coconuts should be 15 by 12 inches long, with a slightly oblong shape. For successful germination, select one that has water inside — you can tell by giving it a gentle shake near your ear and listening for the liquid.
Prepping the Coconut
Fill a large bucket with water and submerge the coconut for 48 to 72 hours. Soaking the coconut helps stimulate germination. In their native habitat, coconuts germinate during the wet season when temperatures are high. Pick a wide, shallow container that has drainage holes in the bottom. A 10-inch-deep, 20-inch-wide container works well, but larger is fine if that’s what you have available. Fill the pot with standard potting soil and then make a well or indentation in the center.
Two Ways to Plant
You have two choices when it comes to planting a coconut: upright or horizontal. For the horizontal method, lay the coconut in the soil well, on its side, and push the soil back around, leaving one-half of the coconut sticking out of the soil. For the upright method, hold the nut in your hand. You’ll see a pointed end and a flat end. The flat end has a rough nub where the stem detached when the coconut fell. Stick the bottom of the coconut into the center of the pot with this flat, nubby side sticking up and push the potting soil around the base of the coconut, leaving the top one-half out of the soil.
Hot, Humid and Wet
Coconuts need sun, warmth and moisture to germinate. Keep the temperature above 70 degrees Fahrenheit and ideally between 90 and 100 F. Unless you live in the tropics, plan to germinate the coconut in a greenhouse or hot, sunny porch. Keep the soil wet — but not soggy — by watering when the top of the potting mix starts to feel dry. In hot weather, especially in clay pots, you may need to water daily. Look for a small shoot in two to three months.
Time to Maturity
Grow the coconut in full sun — either in a container or outdoors — and keep the temperature above 72 F. Water outdoor coconut trees with 1 inch of water each week. Water container-grown coconut trees when the top 1 inch of the soil dries out. You can expect your first coconuts within six years, though it could take up to 10 years from the time the tree sprouts. Cut the coconut from the tree when the outer husk turns brown or let it mature and fall naturally, as long as the falling coconuts don’t pose a danger to people or property.
How to Plant a Coconut Seed
Choosing the Seed
In the United States, you’ll find coconut palms mainly in Hawaii and Florida. If you’re lucky enough to live in or visit these states, you’ll no doubt be able to select a fresh, unhusked coconut at a local stand or market. If you’re outside of those states, you can purchase your seed online. You can also use a de-husked coconut from the store; however, grocery store coconuts sometimes undergo rough handling that can affect their ability to sprout. Get a coconut where the three “eyes” on the round end appear undamaged, as this is where the sprout emerges. Whether you’re planning to plant a husked or unhusked seed, make sure you can hear water sloshing around inside. The more sloshing you hear, the fresher your coconut is and the better your
Preparing to Plant
Whether or not your coconut has a husk, you’ll want to prepare it for germination by soaking it in water for three days prior to planting. Fill a plastic bucket with warm water that is 70 to 90 degrees to kick start the process. Use a rock or brick to gently hold the coconut under the surface of the water to ensure maximum hydration.
Planting a Coconut With an Intact Husk
Planting a coconut with an intact husk is a one-step process. The coconut’s protective husk helps the seed maintain the proper humidity for germination, so you’ll be able to plant your coconut directly into a decorative pot where it can grow for about five years before you have to think about transplanting it. A large, three- to five-gallon planter will give it plenty of room to grow roots that will maintain the health of your tree.
It’s vital to provide well-drained soil for your coconut seed, so line the bottom of your pot with a layer of rocks. Mix soil to fill the pot using one part vermiculite or sand to two parts potting soil. Dig a hole in the center of the soil with a trowel deep enough for two-thirds of the coconut, but leave the top third above the soil. Plant the pointed end of the coconut down in the soil, leaving the part where it was attached to the tree above ground level. Water the seed frequently, keeping the surrounding soil slightly moist but not so wet that the seed begins to rot. If your seed starts to smell, you’ve over-watered and will need to start again with a new seed. Be patient with the process: Coconut seeds take anywhere from three to six months to sprout.
Germinating a Coconut Without a Husk
Coconuts without a protective husk intact can germinate with the help of a plastic bag to help provide the humidity needed for the seed to sprout. Place the coconut in a gallon-sized zippered plastic bag with the three “eyes” toward the top of the bag. Add two tablespoons of water to one corner of the bag to provide humidity. Seal the bag with the coconut inside and put it in a dark, warm place to germinate. You may see a sprout in as little as two weeks using this method, though it normally takes about three months. Once the initial sprout emerges, move the bag to a sunny window sill to continue the growth process. You can wet a paper towel and put it over the root to provide moisture. Leave the plant in the bag for several months this way to let the roots develop before transplanting in a pot. Transplant in soil as described above, making sure all roots are under the surface of the soil. You can put a little sphagnum moss around the roots to keep conditions as close to life in the bag as possible.
Your coconut seedling will be happy as long as it has enough water and light and the temperature stays above 70 degrees. Keep the soil moist at all times; you won’t overwater as long as the soil is well-drained. Place the plant in a sunny window where it will receive a minimum of eight hours of sunlight per day. In winter, you may need to use a heating mat and grow light to provide the right conditions. Your happy coconut palm will grow into a striking, five-foot plant that will add beauty to your home and coconuts to your table.