How to Grow Cilantro Indoors

If you are looking for easy-to-grow aromatic herbs you can harvest in your garden year-round, cilantro (Coriandrum sativum) is a great choice. With the right conditions, growing cilantro indoors rapidly supplies any gardener with an ample herb supply.

Although its origins are difficult to pinpoint, most botanists agree that cilantro hails from the Middle East to the Mediterranean. It is an annual herb that prefers well-drained soil. All parts of the plant are edible, including roots and seeds, and each has a distinct seasoning purpose. This is why it is used in so many culinary settings.

Enjoy cilantro from your home garden at every stage of its lifecycle. Growing cilantro indoors offers many options including microgreens, fully grown leaves, all the way to flowered and seed-producing plants. It can be eaten fresh in salads or cooked into dishes. 

The Epic Seed Starting Bundle

This seed starting bundle is a complete kit designed to help beginners or experienced gardeners start their seeds before transplanting them to their garden or outdoor space.

What is included in the bundle:

• Set of (8) 4-Cell 4″ Trays
• Set of (12) 6-Cell Trays
• Set of (2) 1020 Universal Bottom Trays

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Can You Grow Cilantro Indoors?

Let’s say you would like to grow cilantro, but you live in an apartment with little to no balcony space. Maybe mobility is an issue for you, or the climate in your region gets too warm or too cold for cilantro. No problem at all! As long as conditions are right, it will do well indoors. 

South-facing windows in the northern hemisphere provide cilantro with the ultraviolet light it needs to thrive. In the southern hemisphere, seek out a north-facing window.

If a window is not an option, grow lights are an excellent alternative. Remember that purple LED grow lights will be an adequate light source, but they could make your plants prone to molds. White and yellow grow lights are the closest simulation to actual full sun, which this plant prefers.

Grow cilantro indoors in trays wide enough to give the seedlings plenty of space, but small enough for your indoor growing area. Trays should have drainage holes, and be deep enough to support the cilantro root system.

Another fun method of cilantro growing can be done in a grow tent. Generally grow tents take up a bit more space than a window setup would, but if you find your counter space is more than adequate (two-foot by four-foot wide) this might be the best option. Grow tents contain lights, and help cilantro plants retain the moisture and temperature needed to thrive. 

Although harvesting hydroponically grown cilantro may not provide as much yield as other herbs, it can still be done. In this kind of setting, the right temperature and pH conditions are essential.

How to Grow Cilantro Indoors

If you want to grow cilantro indoors in any of these settings, follow these steps and find out how. You’ll have cilantro in your home year-round. 

Planting

Planting cilantro is best done from seeds, as cilantro seedlings tend to experience transplant shock. Each coriander seedpod contains 1 to 2 seeds, and seeds can be sown relatively close to one another at 2-3 inches apart.

If you sow too many seeds, don’t worry. Overcrowding isn’t a huge issue for cilantro, especially if you have the opportunity to thin seedlings as they rise from the soil to 8-10 inches apart. 

It’s not necessary to soak coriander seed to help growth, but doing so could assist in the germination process. To do this, break the seeds up gently in a plastic bag with a rolling pin. Then soak them in enough water to cover them for 12-24 hours. Afterward, plant cilantro seeds just as you would dry seeds.

For hydroponic setups, use the same seed-soak method detailed above. Then, in three batches, spread cilantro seed in a colander over five to six days. As each batch starts, transfer them into your hydroponic system for harvesting. 

Light

In general, cilantro prefers full sun. This translates to at least six hours per day with a little bit of shade in the hard afternoon sun. Plants enjoy more hours per day of sunlight in colder seasons.

With grow lights, it’s not necessary to find the best location, as you’re already creating optimal conditions. But if you want cilantro growing in a window, be sure you place your trays in a south-facing window in the northern hemisphere, and a north-facing window in the southern hemisphere.

Another great way to ensure cilantro gets the amount of sunlight it needs is to rotate trays daily. This gives cilantro sunlight on each leaf and prevents plants from reaching for sunlight which can cause nutrient deficiencies. Overall, rotating containers will give photosynthesis a boost and allow the plant to absorb necessary nutrients.

If sunlight isn’t enough for cilantro needs in your home, try an indoor growing setup. Grow cilantro indoors under a grow light with a timer, or manually turn the source on and off for the most favorable leaf production. In a grow tent, the same technique applies.

Water

Since cilantro prefers consistently moist soil, start by watering seedlings with a spray bottle. In a setting with a lot of sun or more intense heat, check the soil one to two times per day to ensure it is moist but not overly wet.

If your potting mix tends to dry out often, try watering from below in a tray. Monitor the water content in the tray to ensure there is adequate absorption. If you find the retaining tray is full of water too often, resume watering from above. 

Typically cilantro seeds and seedlings need more water than an established cilantro plant. But make sure the soil does not completely dry out. When the soil is dry, add water. In higher heat settings this will mean watering more frequently. In cooler settings, you’ll have to water less. 

Soil

Cilantro prefers well-drained loamy soil. A good organic potting mix or potting soil will do the trick. Be sure containers have enough drainage and something to catch water from below. 

If soil is a less desirable option, there are other mediums like coir that can be used. Simply break up the medium and place it in a pot to sprout seeds.

If you plant cilantro in a self-watering container, keep an eye on the moisture content of your growing medium. Self-watering containers make watering plants easier, but can encourage mold. For a hydroponic setting, try a full kit, and make sure the water used in the system is the correct pH (6.5-6.7). 

Temperature & Humidity

In situations where the temperature rises above 75 degrees, cilantro is prone to bolting and flowering. This completely changes the flavor of cilantro leaves. Monitor the temperature inside your house and around the growing area. In winter, you will likely have less of a problem with too much sun or heat.

Try not to keep your trays, container, or grow tent near an HVAC system vent. Too much heat dries out the soil and tells cilantro it’s time to start producing seeds to be sown for next year. Too much cool air will stunt plants when you grow cilantro indoors.

Humidity is an important aspect of understanding how to grow cilantro indoors. Too cool and wet of a climate, and you’ll find that cilantro is prone to powdery mildew. 

Grow tents will retain humidity more than open tray growing. Cilantro doesn’t need higher humidity after the seedling stage, and it prefers a drier climate. In grow tent settings, check leaves regularly for evidence of powdery mildew. The same goes for hydroponics where the growing medium will evaporate, providing more humidity. 

Fertilizing

There’s a bit of debate over whether or not to fertilize cilantro. Generally, once plants are established, they will appreciate an infrequent water-soluble fertilizer. Wait at least four weeks after sprouts emerge to apply. If you don’t have fertilizer handy, no problem. As long as you have a rich growing medium, cilantro will do just fine without fertilizer. 

Pruning

Once cilantro gets going, get clipping! As with most herbs, cilantro growth increases with each cut. If you prefer cilantro microgreens, snip one-inch tall seedlings at least twelve hours after the last water. If you are cutting fully grown cilantro leaves, use kitchen shears to clip at the growth point. The more you harvest cilantro tips, the bushier it becomes. 

Once cilantro flowers, the flavor of the rest of the plant changes permanently. You can still clip off flowers at this point to keep growth going but don’t expect to use it in the same manner as you would before. Just like the rest of the plant, fresh cilantro flowers can be eaten raw or cooked. Harvesting cilantro before flowering is best, as the flavor is easiest to work with at this point. 

The best option once the plant begins to flower is to let it bolt and collect cilantro seeds for the next season. You can collect green coriander seeds in a paper bag and in just a few days they’ll be dried and ready for storage. Another method of collecting coriander seeds is to cut bolted stems and hang them upside down inside a bag. As stems dry, seeds will drop into the bag, and you won’t miss a single one. 

Troubleshooting

Insect pests, hungry bunnies, and voracious deer are not a huge issue when growing cilantro in your home. But there are a few things to keep an eye on, most of which are related to light and water conditions. 

Too much water and low light can lead to powdery mildew, a fungus that damages leaves at first, and then the entire plant overall. If you notice powdery mildew on your herbs, remove the damaged parts of your plant and allow the soil to dry some before adding water again.

When soil is too wet, it can also attract fungus gnats which will feed on the roots if left to grow. Adult gnats are easy to control with sticky traps and by reducing the amount of water you apply, but their larvae are a bit trickier as they’re hidden within the soil. Keep a watchful eye out to catch adults quickly so they don’t lay eggs that become those dreaded larvae!

Another situation that arises from too much water or poor drainage is root rot. In this case, the first sign shows when leaves wilt. To check for root rot, lift the root system out of your tray or container and examine the root color. If the roots are brown as opposed to white, it may be time to say goodbye to your plant for the season. If there are still white roots, try removing the rotten ones, and provide your cilantro plant with a new potting mix. 

Coriander plants can also be prone to wilt if they are under-watered. To remedy this, maintain consistent watering, not too wet nor too dry. Moist but not soggy soil is ideal.