How to Grow Marjoram

Marjoram (Origanum majorana) is a perennial herb that's closely related to oregano. It is evergreen in zones 9 and 10, but in most zones it is grown either as an annual or as a potted plant that is brought indoors when the weather turns cold. The low-growing plant has a mounded, shrubby appearance with aromatic, ovate, gray-green leaves that stretch around an inch long. Tiny white or pink flowers bloom from mid- to late summer, though they are not especially showy. Best planted in the spring, marjoram grows slowly and eventually becomes a spreading ground cover. Note that gastrointestinal irritants within marjoram technically make it toxic to humans, as well as to pets. 

How to Plant Marjoram

When to Plant

Marjoram can be difficult to start from seed, so it's often best to begin with small plants from the nursery. Plant in the spring after the threat of frost has passed. If you want to start marjoram from seed, either direct sow in the garden about two weeks after your last spring frost or plant indoors about eight weeks before your last frost.

Selecting a Planting Site

The key to growing this herb is to plant it in well-draining soil and ample sunlight. Container growth also is an option. Keep weeds away from the marjoram, as they will compete for nutrients and moisture. And make sure no taller plants will leaf out and shade it in the spring.

Spacing, Depth, and Support

Plant seeds 1/4 inch deep, or situate nursery plants at the same depth they were growing in their previous container. Space plants about a foot apart. A support structure shouldn't be necessary.

Marjoram Plant Care

Light

Marjoram plants love sunlight. Aim to give them full sun, meaning at least six hours of direct sunlight on most days. If growing indoors, choose your brightest window. Or you can move the plant around your home to "chase" the light throughout the day to ensure it gets enough rays.

Soil

Plant marjoram in loose, sandy or loamy, well-draining soil with a slightly acidic to slightly alkaline soil pH. Good drainage is critical, as the herb is susceptible to root rot. 

Water

Keep the soil for young plants lightly moist but not soggy. About 1 inch of water per week should do. Established plants have good drought-tolerance, though you shouldn't allow the soil to dry out completely. Avoid overhead watering, which can lead to fungal problems. And water early in the day, so any wet foliage has plenty of time to dry in the sun before nightfall.

Temperature and Humidity

A native of mild Mediterranean climates, marjoram plants grow best at temperatures between 60 and 70 degrees Fahrenheit. Avoid temperatures below 50 degrees Fahrenheit. Moreover, marjoram doesn't need high humidity—in fact, it really doesn't like it.

Fertilizer

While fertilizing your marjoram isn't a must, giving it regular feedings can help it grow more lush and full. If you choose to fertilize your plant, feed it once a month with a liquid blend formulated for herbs, following label instructions. Alternately, you can amend the plant's soil with organic matter to increase the nutrient density.

Pollination

Marjoram self-pollinates, and its flowers are highly attractive to bees and butterflies.

Types of Marjoram

In addition to the main species plant, Origanum majorana, there is also a variegated form that has gray-green leaves edged with creamy white. It is a more compact, slower-growing plant that is usually kept as an ornamental.

You also might want to consider another type of marjoram for your garden. Greek marjoram (Origanum onites) has leaves that turn gold in the summer. It is hardy in zones 6 to 12 and is often grown to attract bees, butterflies, and other pollinators. Its taste is similar to Origanum majorana, along with its cultural needs.

Marjoram vs. Oregano

Marjoram and oregano are closely related plants, both being members of the mint family. They even look similar as bushy herbs with small leaves. However, oregano's aroma and flavor are much stronger than marjoram's. Oregano leans spicy and slightly bitter while marjoram is more sweet and floral. 

Harvesting Marjoram

It can take two to three months for your plants to be strong enough for harvesting. Snip off sprigs as needed, but don't take more than a third of the plant at once. You'll be able to take multiple cuttings per growing season. 

Use marjoram fresh or dried. To dry sprigs, hang them upside-down in a cool, dry place with good air flow. Once the leaves are brittle, remove them from the stems to store in an airtight container. Keep in mind that the delicate taste of marjoram can get lost in some foods, so if you're using it as a substitute for oregano, add more than you would oregano.

How to Grow Marjoram in Pots

Container growth is a good option for marjoram if you don't have the garden space or can't keep it outside over the winter. You just have to give it enough light indoors. Use a container that's at least 6 inches wide and at least 6 to 8 inches deep. Make sure the container has drainage holes. You can aid drainage by using an unglazed clay pot, which allows excess soil moisture to evaporate through its walls.

Pruning

Pinch back stems before flowers appear to encourage a bushy growth habit. Then, as marjoram starts to bloom, cut it close to the ground to stimulate new growth of more flavorful leaves.

Propagating Marjoram

Marjoram appreciates being divided, so it doesn't become too crowded. A nd a single plant can provide you with the herb for years to come if given the necessary winter care. Simply dig up the root clump of an established plant in the fall, divide it into pieces, and replant the pieces into separate pots or new garden locations.

Marjoram also can be propagated by cuttings, which is another way to create new plants for future growing seasons even if you're growing your marjoram as an annual. The best time to take cuttings is in the late spring to midsummer. Here's how:

1. Cut a 4- to 6-inch piece of healthy stem.
2. Remove foliage on the lower half of the stem, along with any flowers and buds.
3. Dip the cut end in rooting hormone, and then plant the cutting in a small container of moist soilless potting mix. Place it in bright, indirect light.
4. Keep the soil lightly moist but not soggy. Once you see new leaf growth and feel slight resistance when you gently tug on the stem, you'll know roots have formed.
   

How to Grow Marjoram From Seed

Growing marjoram from seeds can be tricky. The seeds are slow to germinate, taking around two to three weeks, and they need warm soil. Starting seeds indoors usually is more successful than direct sowing.

First, soak the seeds overnight, which can help encourage germination. Plant them in a starter tray filled with moist seed-starting mix. Press them slightly into the soil. Place the tray in a bright location, and keep the soil moist until the seeds sprout. For best results, keep temperatures right at 70 degrees Fahrenheit until the seedlings develop their true leaves.

Harden off the seedlings before transplanting them outdoors after the threat of frost has passed. Seedlings should have at least three pairs of true leaves before transplanting. Gradually expose them to outdoor conditions for about a week until you permanently leave them outside.

Potting and Repotting Marjoram

Use a loose, well-draining potting mix for growing marjoram. You likely won't have to repot within a growing season unless you start with a container that's too small. However, it's a good idea to refresh the potting mix every two to three years. Gently ease the plant out of its container, shake off excess soil, and replant it at the same depth with fresh potting mix. If you see roots growing out of the drainage holes or up above the soil line, transplant to one container size up.

Overwintering

If you don't live within marjoram's growing zones, you can dig up and pot garden plants. Bring them inside before the first fall frost hits. But know that overwintering indoors isn't always successful, as marjoram needs lots of light and stable temperatures. Keep your plant away from any drafts. And consider grow lights if you don't have a bright window that gets several hours of sun per day.

Common Pests and Plant Diseases

Marjoram has few serious pest and disease problems when grown in the garden, though it can develop root rot in waterlogged soils.

But like many houseplants, it has to contend with a few common pests when grown indoors. Aphids, mealybugs, and spider mites can all be an issue for the herb. If you notice signs of an infestation on your plant, move it away from other plants as soon as possible. You can try manually removing pests by either rubbing them off or running the plant under a firm spray of water. If that doesn't work, treat the plant with insecticidal soap or neem oil.

Most diseases come about from too much humidity in the plant's environment. If the air outside or in your home is too damp, your plant might be prone to powdery mildew or botrytis blight.