Days to germination: 10 to 14 days
Days to harvest: 90 to 100 days
Light requirements: Full sun
Water requirements: Occasional watering
Soil: Loose, sandy and well-drained
Container: Very suitable, especially indoors
Marjoram has a flavor much like oregano, only milder and sweeter. It has Mediterranean origins but is best known as an herb used in Italian cuisine. And true to its roots, marjoram will only survive in zones 8 to 10. If you take extra care of your plants during the winters, you may grow marjoram outdoors in zone 7.
It is a perennial, but you can also grow it as an annual in areas that are too cold during the winter for it to survive. Growing it indoors is another option to keep it growing for several years. It won’t grow to be an overly large plant, usually around 1 to 2 feet high.
There are a few different varieties, including knotted marjoram and sweet marjoram. Most home gardeners grow the sweet type. You can use it in nearly any kind of savory dish, from meat and fish to vegetables and soups.
Starting from Seed
Marjoram grows well from seed, and you can either start your plants indoors or sow them directly out into the garden. For an early start, plant marjoram seeds inside 8 weeks before your last frost date. You shouldn’t bury the seeds too deeply. Just sprinkle a little bit of soil over top of the seeds on the surface. Keep them moist but not overly wet in a sunny spot until they sprout.
The seeds are very tiny, so most people don’t bother trying to separate them to plant individually. Just plant a few in each seedling pot, and thin them out to 1 plant per pot or tray cell.
Once you’ve passed your local frost date, you can put your marjoram plants outside. You can plant marjoram anywhere that it will get all-day sun, even in relatively poor soil. It will thrive in sandy soil so you might want to add some sand when you are digging up an area to plant in. Allow for 8 to 10 inches of space around the plant.
If you prefer not to transplant seedlings, you can just plant your marjoram seeds out after the frosts are finished. Plant seeds about half an inch deep allowing for the same spacing between plants, or sow more closely and thin out after they begin to sprout.
If you have very poor or sandy soil, you may want to give your plants a fertilizer feeding each spring but otherwise they won’t need any added nutrients. They are extremely low-maintenance.
For the first month or so, you will want to water your plants whenever they get dry but after that they should thrive just fine without any additional care from you.
The flowers will attract insects and bees to your garden, which can be very helpful if you are growing vegetables or fruits that need pollinators.
When you start to get frosts in the fall, the plant will quickly die back. A cover of mulch can help marjoram survive the winter so that you have fresh new plants in the spring. This is definitely a must if you are trying to overwinter marjoram in zones 7 or 8.
Anyone living above zone 7 will want to keep their marjoram indoors, and growing in containers works very well for this plant. Since you will be growing your marjoram for several years, you should provide it with enough root space and a large pot. A 10 to 12 inch container should suffice.
Use a light or sandy potting mix, with extra gravel for drainage. Keep your containers in a sunny location and only water when you feel the soil is quite dry. You really don’t need to water marjoram as frequently as many other herbs.
As mentioned, it only gets to be around a foot or two high. But you can keep your plants shorter if you wish by vigorous harvesting of the top leaves and stems.
Pests and Diseases
Not very many insects are going to be interested in your marjoram plants except for the occasional aphid or spider mite. Neither one is particularly harmful unless your plants are covered in them. If you see either of these tiny pests, you can just give them a spray with plain water to wash them off. That won’t keep them away for too long, so you should check your plants daily. For a more lasting repellent, use a pyrethrin-based insecticide spray.
Once you spray your plant, don’t harvest any leaves for a few days. And when you do, wash them well before using.
Harvest and Storage
You should be able to start picking marjoram leaves for use about 3 months from when you planted the seeds. Your plants should be at least 3 inches tall, but only pick a few leaves at a time until they are 6 inches high. Then you can harvest more regularly.
Like most herbs, you need to do your harvesting before the plant goes to flower. After that, the leaves will be too bitter to use. Marjoram usually blooms in mid to late summer. You can delay this deadline by cutting off the flower stalks as they begin to form. Your plant will grow slower into the autumn if you do this, but you should still be able to harvest leaves almost until winter as long as it doesn’t flower.
If you are growing your marjoram as an annual, you should let at least one plant flower. Then you can collect the seed for your next spring planting.
Fresh leaves will keep in the fridge for 3 or 4 days. They store the best if you keep them moist in a plastic bag with damp paper towel, in the crisper drawer.
Marjoram is best used fresh from the plant, but it can also be dried. Don’t let them dry right in the sunlight though, or they will lose their flavor very quickly. Even dried, marjoram doesn’t last as long as other herbs. After about 3 months, it will start to lose its flavor and aroma.