The cilantro plant (Coriandrum sativum) is relatively an easy-to-care herb. It is grown as an annual herb and belongs to the family Apiaceae. Many gardeners prefer growing cilantro indoors, some even year-round, to have a fresh supply for cooking their favorite dishes. However, sometimes cilantro plants fail to grow properly. In this post, you will find out the main reasons for cilantro not growing properly indoors/in pots/in aerogarden, and what you can do to improve cilantro growth and make it grow faster. Also, you will learn about cilantro not growing in an aerogarden.
Let’s briefly discuss the reasons for cilantro not growing.
The main reasons for the cilantro plant not growing are disease, overcrowding of plants, root-bound plant, overwatering or underwatering, and exposure to high temperatures. Several environmental stresses and wrong growing practices will make these plants not grow properly.
Keep reading to figure out the reasons that are inhibiting the growth of your cilantro plants. Plus, what you can do to solve this problem, depending on your causes.
Reasons For Cilantro Not Growing
Like other plants, cilantro plants need light, air, water, and fertile soil for proper growth and nourishment. Along with these basic needs, several variables are also responsible for the healthy growth of these herbs. If any of these factors is lacking, the coriander plants will grow improperly.
The reasons for cilantro not growing are mentioned in detail. Read on to explore more.
Reason 1: Improper watering
Moderate watering is the key to the successful growth of cilantro plants. The is one of the most common reasons for improper growth in coriander. The coriander seeds will not germinate in the absence of water either (read about germination problems here, opens in a new tab). In fact, cilantro loves good watering and needs it to grow properly.
Underwatering causes chlorosis (deficiency in chlorophyll production, leading to yellowing of leaves) in cilantro. But if you overwater plants, the roots will get waterlogged. As a consequence, the roots hardly absorb the required oxygen and ultimately fail to function. Lack of oxygen can easily kill the plants. Besides, overwatering promotes fungal diseases that badly affect the plant and result in stunted growth. Too much water also causes wilting of coriander plants.
Follow these tips to solve the water-related growth problem of cilantro plants.
- Coriander plants should be planted in soil with good drainage.
- If you are starting seeds, keep the soil moist after sowing.
- Depending on your climate, around one inch of water per week is enough for coriander plants.
- However, during warm weather, plants may need more water.
- For mature plants, let the soil dry before watering again.
- Make sure that the pots have drainage holes on the bottom.
- Water pot plants more frequently (quicker evaporation).
- Place a saucer on the bottom of indoor plants so that the excess water can drain out of the pots.
- It is better to use unchlorinated water for watering cilantro. If you are using tap water, let it sit for 24 hours before using it.
Put your finger in 1 inch of topsoil to check whether the plant is getting enough water or not. If the soil is moist, it means the plant is getting enough water. If the top 2 inches are dusty and dry, you are underwatering the plant. You can also use a soil meter like this to easily see moisture levels. Make sure to water regularly and sufficiently, because lack of water can will cause water stress and bolting in cilantro.
Reason 2: Overcrowding of cilantro plants
Overcrowding is another reason for the slowed growth of cilantro plants. Growing plants too close to each other results in a lack of air circulation and sunlight between the plants. As a consequence, the plants fail to dry out quickly after watering and get enough light exposure.
When the plant parts remain wet for prolonged periods, they are susceptible to different fungal and bacterial diseases. Therefore, coriander plants suffer and stop growing properly.
These tips may help you to improve air circulation between these plants.
- When sowing seeds, make sure to keep a gap of 6 inches (15 cm).
- Cilantro plants produce dense foliage, so while transplanting seedlings, keep 8-10 inches (20-25 cm) of space between coriander plants.
- If you aim to harvest coriander seeds, sow the seeds 8-10 inches apart. The rows should be 15 inches apart.
- For improving the air circulation of indoor plants, use a small fan.
Reason 3: Prolonged exposure to high temperatures
Cilantro plants are too sensitive to temperature. Being cool-season crops, the cilantro plants bolt if exposed to high temperatures for long periods. The best temperature for the growth of coriander is between 50 and 85 degrees F (10-29 Celsius). That’s why it’s recommended to start sowing seeds in spring. You can even grow cilantro successfully in winter. Significant daylight changes in winter help cilantro plants grow vigorously.
Cilantro plants can tolerate temperatures as low as 10 degrees F (-12 Celsius), though not recommended. If the temperature rises above 85 degrees F (29 C), the coriander plant bolts. Bolting refers to the vertical growth of shoots to produce flowers and seeds instead of leaves. The plant loses flavor as a result of bolting.
To prevent bolting in cilantro, you can follow these tips:
- Avoid planting cilantro plants in places where they receive high daytime temperatures.
- Move the pot plants to some shade during high-temperature hours. Provide shade for a few hours a day.
- Add some hay or mulch around the plants to help keep the soil cool.
- Start seeds indoors early if there is a risk of bolting due to the high temperature in your region.
Reason 4: Limited sunlight exposure
Although cilantro is a cool-season crop, it needs 6 to 8 hours of direct sunlight to grow properly. Often, the indoor plants growing on the windowsill suffer the most, due to limited sunlight exposure. The plant can’t carry out photosynthesis properly in limited light. As a result, plant growth and development are both affected.
Here are the tips to improve the light condition and exposure for indoor plants.
- Place indoor plants in south-facing windows so they can receive 6 hours of direct sunlight.
- You can use a simple LED grow light like this indoors for cilantro seedlings and plants, especially in winter.
- Make sure to suspend grow lights just above the plants (around 4 inches, or 10 cm). Raise the light as the plants grow in size.
Reason 5: Wrong Planting Time
Coriander seeds often fail to germinate if you sow them in the wrong season. Although it is a cool-season herb, it requires warm soil to germinate. Avoid sowing cilantro seeds when it’s hot, always do it before it starts to get hot.
In the USDA zones 8, 9, and 10, plant the cilantro seeds in the fall. In this way, the crop will last till the late spring. For Northern areas of the US and most of Europe, late spring is the ideal time to plant cilantro when the frost danger has passed. For a steady supply of coriander throughout the growing season, sow seeds every 3 to 4 weeks.
You can also sow seeds in winter, especially if growing indoors with a grow light. Cilantro plants love having a good day-night cycle, and it helps them grow very well in winter.
Reason 6: Pests and diseases
Common bacterial, fungal, and viral diseases are some of the major reasons why the cilantro plant might not be growing. Coriander bacterial blight and soft rot are the bacterial diseases that cause water-soaked lesions on the plant parts. It causes yellowing of plant parts and eventually kills them.
Powdery mildew and damping off are the fungal diseases of coriander plants. Damping-off causes seeds to rot and fail to germinate.
Aphids (look like small black or greenish dots) and leaf-hoppers are the pests of cilantro. Aphids suck the sap of the plant and secrete honeydew that promotes sooty mold growth on the plant parts.
Here are a few tips that will help in controlling the pest and diseases in cilantro.
- Make sure to purchase clean and tested seeds to avoid seed-borne diseases.
- Avoid planting cilantro in the same soil that has a previous history of the disease.
- Use natural ways to get rid of them – organic neem oil spray or insecticidal soap like this to keep pests away from plants. Insecticidal soap will help treat powdery mildew, aphids, mealybugs, whiteflies, thrips and more. Horticultural oils also help get rid of pests, plus their eggs safely.
Reason 7: Lack of Nutrients
Nutrients are crucial for the growth and development of plants. Cilantro doesn’t require much fertilizer to grow, but potted plants may need fertilization. If the leaves are turning yellow, and you are sure that the yellowing is due to nutrition deficiency, fertilize your plants with organic fertilizer. An organic seaweed fertilizer like this is great for cilantro plants.
You can use low nitrogen fertilizer to feed cilantro. But if you are side dressing your plants with compost or organic manure, there is no need to use synthetic fertilizer. Diluted fish emulsion is another option for feeding these plants. Make sure not to over-fertilize cilantro as it can weaken the roots and burn the plant. When using synthetic fertilizer, check the application details on the packaging.
Reason 8: Improper Planting
Cilantro will not grow properly if seeds are planted too deep. Plant the seeds no more than 0.5-1″ deep and 2 to 4 inches apart. Cover the seeds with a light sprinkle of the potting mix. If temperatures are low, you can cover freshly sown seeds with a thin film. Cilantro seeds take around 1-3 weeks to germinate.
To save the outdoor seeds from birds, use a mesh, or shade net until germination. Don’t worry if the seeds fail to germinate due to some reason. Plant new seeds if you want to enjoy the fresh harvest in the coming months.
If you are having issues with coriander seed germination, see this post for more information and tips.
Further suggestions to improve cilantro growth
Here are some tips that you can follow to improve the growth of cilantro.
Plant coriander in well-drained soil that is rich in organic matter. Prepare a potting mix by adding 50% garden soil, 30% compost, and 20% coco peat. Or purchase a potting mix specific for herbs.
Make sure to keep an eye on the weed growth as they compete with cilantro for nutrition and light. Remove the weeds regularly.
Use the best quality seeds for planting cilantro. Avoid planting grocery-bought cilantro as they often have a low germination rate. Don’t use chemical pesticides on cilantro. Use organic solutions for controlling pests and diseases.
Remove any remains of the previous crop from the soil before planting new seeds. Use a soaker hose or drip irrigation for outdoor plants. Avoid wetting the foliage to prevent fungal diseases.
Cilantro not growing in an aerogarden
An aerogarden is a hydroponic system for growing plants without soil. Generally, it is a hydroculture technique that involves growing plants by feeding them with mineral nutrients dissolved in water.
If your cilantro is having trouble when growing in an aerogarden, a few reasons are possible.
- Your cilantro may not be growing well if you haven’t placed it in a sunny spot. These plants need enough sunlight to grow properly. So, place your aerogarden in a sunny spot or near a south-facing window. In case of insufficient sunlight, use a LED grow light for your aero garden. Turn on the grow lights 14 to 15 hours a day to provide adequate light to plants.
- If the cilantro plant in your garden is suffering from any bacterial or fungal disease, it may not grow properly. Keep your aerogarden clean by wiping it every week. Change water every few weeks, and remove dead leaves regularly if there are any.
- If your aerogarden is receiving too much light during warm weather, the cilantro will suffer badly. So, transfer it to a shady place during the hottest part of the day, for a few hours.
Final Words
Cilantro is a great herb that adds flavor and beauty to your dishes. It might be challenging to grow cilantro if any of its basic needs is missing. If you are having a problem growing cilantro, follow the tips mentioned in the post. If all the tips and tricks fail, replant – it grows quickly and you might have better luck this time.
To learn more about growing herbs, see this page. And to learn more about growing cilantro (coriander), you can visit this page.