Oregano starts as a ground-hugging rosette of leaves, but it can easily grow to about 2 feet tall. It’s generally planted in the spring and grows quickly, providing leaves suitable for cooking almost immediately. Note that oregano is toxic to pets, so be mindful of where you plant it.
Selecting a Planting Site
Oregano is one of those Mediterranean herbs that grow well in full sun and lean-to-average soil that’s well-drained. Rich soil can dilute the pungency of the herb. So oregano is a good choice for those sunny areas of your garden with poor soil that isn’t suitable for many other plants. Just make sure it isn’t situated too close to taller plants that will leaf out and shade the oregano.
Spacing, Depth, and Support
Space oregano plants around 8 to 10 inches apart. Seeds should be just slightly pressed into the soil, as they need light to germinate. And nursery plants should be planted at the same depth they were growing in their container. A support structure shouldn’t be necessary.
Oregano Plant Care
Light
Most oregano varieties need full sun, meaning at least six hours of direct sunlight on most days. However, some varieties, including golden oregano, prefer a little shade from strong sunlight to prevent their leaves from scorching.
Soil
A sandy loam is ideal for growing oregano. If the soil is moist with lots of organic matter, oregano won’t perform as well as it does in well-drained, light, dry soil. Also, a slightly acidic to neutral soil pH is best.
Water
Oregano only needs about an inch of water per week and is tolerant of moderate drought. Allow the soil to dry out between waterings. Overwatering can cause root rot and other problems.
Temperature and Humidity
Oregano can tolerate heat and even fairly cold temperatures, depending on the variety. Its ideal growing conditions are around 60 to 80 degrees Fahrenheit. It generally does not like high humidity and must have sharp soil drainage and good air circulation in humid climates.
Fertilizer
Oregano typically doesn’t need fertilization, as it can thrive in poor soil. In fact, large amounts of nutrients, such as nitrogen, can change the flavor of the herb.
Pollination
Oregano is a great herb to attract beneficial pollinators to your garden. Bees and other insects help to pollinate its small flowers.
Types of Oregano
Here are some common oregano varieties to consider:
Origanum vulgare (common oregano): This species is the oregano that many people use for cooking.Origanum vulgare ‘Aureum’ (golden oregano): This cultivar has lighter leaves and a milder flavor than the main species plant. It is more popular as an ornamental plant than a cooking herb.Origanum heracleoticum (Greek oregano): This species also is commonly used for cooking and has a fairly strong flavor.
Oregano vs. Thyme
Both oregano and thyme thrive in similar growing conditions: lots of light and fairly dry soil. They also look similar at first glance. However, oregano leaves tend to be slightly wider and greener than thyme’s typically narrow, gray-green foliage. Oregano also has more of a pungent earthy aroma than thyme’s lighter and more floral scent.
Harvesting Oregano
You can begin harvesting oregano leaves once your plant has reached 4 to 5 inches tall. Simply trim off sprigs with just the leaves you need for cooking at that time, leaving the rest of the plant to continue growing. Then, run your fingers down the stem to strip off the leaves. The most flavorful oregano leaves occur right before the plant blooms in the summer. So if you plan to take sprigs for drying, that’s the best time to do it. But you can still snip off leaves at any point during the growing season for cooking or drying. Fresh sprigs can be refrigerated for about a week or frozen for about a year. Hang sprigs upside down in a dark, cool spot with good air circulation to dry. Then, strip the leaves, and store them in an airtight container. Dried oregano has a stronger flavor than fresh leaves, and it should be good for about two to three years.
How to Grow Oregano in Pots
Oregano is well-suited to growing in pots and a good choice for a windowsill herb garden indoors. Containers generally dry out faster than garden soil, so this can help to create the fairly dry environment that oregano likes. Just make sure the container you select has adequate drainage holes. Unglazed clay is an ideal material because it will allow excess soil moisture to evaporate through its walls as well. A container that’s around 10 to 14 inches across and 6 to 8 inches deep should suffice.
Pruning
Oregano needs regular pinching back of its growing tips, beginning when the plant is about 4 inches tall. This will promote a bushy growth habit and help to prevent leggy, straggly growth. It also can delay flowering, which is best if you want the leaves to be as flavorful as possible for culinary use. As the plant grows larger, this pinch-back ritual should be a weekly affair. If the plant becomes overly woody, cutting the stems all the way back to the ground will encourage more stems to sprout from the base. And ultimately this will result in a fuller plant.
Propagating Oregano
Oregano is best propagated from divisions or cuttings. (Because different species of oregano can cross-pollinate, you might not get what you expect from seeds you save from garden plants.) Both dividing a mature plant and taking cuttings can help to rejuvenate it, resulting in bushier growth and a healthier harvest. The best time to divide a plant is in the early spring or fall. Here’s how: Cuttings can be taken at any time when the plant is actively growing, though the spring and early summer are best because the stems are still green and pliable. Here’s how:
How to Grow Oregano From Seed
Oregano seeds require some light to germinate, so cover seeds very lightly with soil. Use a seed-starting mix in a small container, and keep it moist but not soggy. Place the container in a warm spot—roughly 70 degrees Fahrenheit—and in bright, indirect light. Germination should occur within a week. Harden off the seedlings before planting them outside.
Potting and Repotting Oregano
For potted oregano, you can use any well-draining, general-purpose potting mix. To improve drainage, consider blending it with some extra sand, perlite, or vermiculite. It’s generally a good idea to repot a mature oregano plant every couple of years, dividing it as necessary to ensure that light can reach all areas of the plant.
Overwintering
Oregano generally only requires overwintering maintenance in zones 4 and colder, though be sure to check the growing requirements on your particular variety. In cold-winter climates, cut back the stems of the oregano plant after the first frost kills the foliage. Leave a short umbrella of stems to protect the root ball. Also, cover the soil with 3 to 4 inches of dry mulch for the winter. Remove the mulch in the spring as soon as the snow melts.
Common Pests and Plant Diseases
Few pests and diseases bother oregano plants. However, keep an eye out for spider mites and aphids on the foliage. Also, watch out for root rot and other fungal diseases that can arise in wet soils. Correcting the oregano plant’s growing conditions often can help to resolve minor pest and disease issues.
