Providing two spices from one seed — nutmeg and mace — the nutmeg tree (Myristica fragrans) is an aromatic evergreen that grows in most tropical countries. Hardy in U.S. Department of Agriculture plant hardiness zones 10 through 11, this spreading tree grows 30 to 40 feet tall and bears cream-colored flowers followed by yellow, fleshy fruit similar to apricots. Ripe fruit splits open, revealing glossy, purple-brown seeds partially covered by scarlet skins, called arils.
Nutmeg and Mace
Separating nutmeg from its mace-producing aril improves germination rates. A spice used to flavor milk dishes, cookies, cakes, fruit pies, custards and punches, nutmeg is the purple-brown inner seed of the nutmeg tree fruit. Mace, which is an ingredient in savory dishes, ketchups and pickles, is made from the aril that covers the seed.
You should remove the aril before sowing nutmeg. To do so, sterilize a small, sharp knife by wiping the blade with rubbing alcohol, and then cut the aril at its base it where it joins the nut. Peel it off, taking care not to damage the nut. You can discard the aril or place it in a dry, sunny area for 10 to 15 days until it turns brown and dry, ready for grinding into mace.
Freshness and Moisture
Only fresh, moist nutmeg seeds germinate well. Unfortunately, nutmeg seeds dry out quickly. If left uncovered at room temperature, a nutmeg seed can lose its ability to sprout in as little as seven days. For best results, plant your nutmeg seeds promptly after harvest.
When immediate planting isn't possible, store the seeds from your nutmeg plant in sealed plastic bags in the refrigerator. There they will stay viable for up to 45 days. No matter when you're ready to plant, soak your nutmeg seeds for 24 hours in clean water first to increase moisture levels and raise germination rates.
After soaking, fill a 5-inch plant pot containing drainage holes with free-draining potting soil and sow the nutmeg 1 inch beneath the soil surface. Water the pot until water appears through the drainage holes, allow it to drain and stand it in an area where temperatures are between 77 and 86 degrees Fahrenheit. Apply water regularly so the potting soil remains constantly moist but not sodden. Nutmeg seeds take one month or longer to sprout.
Young Tree Care
A young nutmeg tree thrives in a partially shaded but warm and humid environment. Place a newly germinated nutmeg tree in an indoor area that receives four to six hours of sunlight a day, such as a west-facing conservatory or windowsill. Mist the young tree twice a day with clean water from a fine mist sprayer, coating the foliage but stopping before water drips from the plant.
Water your young nutmeg tree regularly so the soil remains moist and allow the pot to drain thoroughly before returning it to its drip tray. Turn the tree 180 degrees every day to prevent it from leaning toward the light.
Older Tree Care
Transplant your nutmeg tree into larger pots as it grows before planting outdoors. A nutmeg tree is ready for transplanting into a larger pot when its roots fill the base of its current pot. Select a pot 2 inches wider with drainage holes and transfer your nutmeg tree into it, setting the plant so that the top layer of soil is 1 inch below the rim. Water your freshly transplanted nutmeg tree thoroughly and allow it to drain.
Continue transplanting the nutmeg tree into larger pots each time it fills its current pot. When the tree's roots grow large enough to fill a 5-gallon pot, plant it outdoors. Plant in late spring, choosing a sunny or lightly shaded location where the soil drains well and is rich with organic matter. If planting multiple nutmeg trees into the landscape, allow approximately 30 to 40 feet between them.
Nutmeg Propagation and Fruiting
If desired, you can continue growing your nutmeg tree indoors. Nutmegs are dioecious, however, which means that each plant is either male or female and cannot fertilize itself. To get fruit from an indoor plant, you'll need to set your potted plant outside each spring or get two plants and pollinate them by hand.
You'll also need patience. Nutmeg trees don't begin to fruit until they're around five to eight years of age, and some nutmeg plants take even longer. Even when production begins, your nutmeg tree won't perform at its fruiting peak until it's around 25. It' worth the wait, however, since nutmeg trees produce fruit for 60 years or more.