Ultimate Guide to Grow Cilantro Indoors Using Hydroponics?

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Cilantro is a popular herb in cuisines around the world. Its aroma and flavor make bland dishes extraordinary. If you love cilantro, you may also want to grow it yourself. Even more exciting is growing cilantro indoors.

This post is the ultimate guide to growing cilantro indoors. Although you can grow cilantro well in soil, we focus on hydroponically growing cilantro. Hydroponics has several benefits over soil, especially considering indoor gardening.

Cilantro, when it matures, produces seeds. These seeds are also consumable and known as coriander seeds. If producing coriander seeds is your goal, I don’t suggest growing them indoors. The entire article is based on the assumption that you grow cilantro for its edible leaves.

Benefits of growing cilantro indoors Hydroponically.

Indoor gardening has gained popularity in recent years. Hydroponics and technological advances like grow lights and tents have all helped. Here are a few benefits of growing cilantro indoors using hydroponics.

Cilantro can thrive under Low Light.

Cilantro is a shade-loving herb. Unlike basil, it can thrive even with very little light. You can comfortably grow cilantro in your window. About four hours of sunlight is sufficient for a healthy cilantro plant.

If you don’t have a place where even four hours of sunlight is scarce or live in a country where sunlight is very dim for a season, you can supplement cilantro with grow light. In such cases, you can keep the lights on for about 8 hours daily.

Hydroponic cilantro needs little to no care.

The beauty of growing in hydroponics is that it’s low maintenance. Some hydroponic systems like Kratky are known for their set-it-and-forget-it nature. You do the setup once and then (hypothetically) come back on harvest day.

Nonetheless, all hydroponic systems are free from tasks such as removing weeds, regular watering, etc.

Cilantro can repel bugs.

Cilantro’s strong smell can repel some bugs. Most notably, cilantro is known for aphids, Colorado potato beetles, and spider mites. Although these bugs don’t threaten humans, they can save other plants nearby. So, if you’re growing an indoor garden with several plants, having a cilantro plant among them helps all the other.

Related: Benefits Of Growing Coriander And Basil Together

There isn’t a better way to get fresh cilantro.

Most of us consume store-bought cilantro. But cilantro’s shelf life isn’t great, especially if it can’t stand a day without being attached to its roots. Even inside your refrigerator, cilantro can wilt and decay soon. You need to keep it in a small bowl of water to keep it alive for a little longer. But it isn’t convenient.

When you grow cilantro indoors, you avoid almost all these problems. Just pick the leaves whenever you need them and directly consume them.

Cilantro fills the room with its aroma.

Why would you spend on chemical air fresheners when you can naturally fill your room with cilantro’s aroma? Besides the flavor, cilantro’s aroma is another prime reason we use it in cooking. When you grow it indoors, the plant’s natural aroma spreads all around the room every time you pinch it. Also, hydroponically grown cilantro roots are aromatic when in good health.

Indoor cilantro suffers less from pests and diseases.

The outside environment exposes the plant (any plant) to various pests and diseases. Commercial farmers use a controlled environment to grow cilantro, herbs, and veggies. But when you grow cilantro indoors, it’s like a controlled environment to some extent. Although complete bypassing is impossible, most pests and diseases can be avoided this way.

How to start cilantro from seeds?

Cilantro seeds, or coriander seeds, are used in daily cooking and are inseparable from Asian cuisines. Thus, finding seeds is easy.

You can use these seeds to start a cilantro plant, but we advise against doing this if you’re serious about growing. Untreated seeds contain pathogens that harm their host plants and can spread to nearby plants. Therefore, buy a packet of cilantro seeds that are treated for pathogens. It may cost a little more, but the extra cost is all worth it.

Starting cilantro seeds is easy. But there are many methods. While soaking and tightly binding the seeds all work, I often think they are unnecessary.

You can directly sow the seeds in your growing medium to grow hydroponically. You could use coco peat pallets, grow sponge, rock wool, or oasis cubes. Add two or three seeds per hole to increase the sowing success rate. Cilantro can grow crowded, so thinning is optional when it grows.

As you sow the seeds, wet the medium with pH-neutral water. You could also use a light-concentration nutrient solution. Make sure its EC is less than 0.8. The growing medium should be wet but not soaking wet. Overwatering can cause the seeds and seedlings to rot rather than grow into healthy plants.

Water the plant every other day. Coriander/cilantro seeds germinate in about 7-14 days. If it takes longer than 14 days, the seeds are probably infertile. In about a, you can transplant the seedlings to the hydroponic system. You can also look for clues, like the roots coming from the growing medium and transplant. The seedlings will have at least one set of true leaves at the transplanting stage.

Which hydroponic system works well for cilantro?

Cilantro grows in any hydroponic system. It’s a pretty easygoing plant.

But why would you need a complicated system if cilantro is so easy to grow? You can grow cilantro using a passive, set-it-and-forget-it method like Kratky. Kratky hydroponics is the easiest to set up—you can call it growing cilantro in water. We prefer the Kratky method for growing cilantro indoors, as it’s easy and cheap to set up and requires low maintenance.

Fill a one-gallon bucket (four liters) with nutrient solution. In the next section, we will discuss how to prepare nutrient solutions. Make a hole in the bucket’s lid that fits your net cup size. Insert the lid and then a net cup. You can directly transplant the seedling into this net cup.

Make sure the bottom of the net cup touches the nutrient solution. In the Kratky method, the seedling uses the nutrients to grow. As it grows, the water level goes down. The air-suspended roots become oxygen roots and breathe air. This is important to prevent root rot, so don’t fill the bucket with more nutrients. You don’t have to do anything as long as the tips of the roots touch the nutrient solution.

Besides Kratky, you can also grow cilantro using a deep water culture (DWC) system. The main difference is that you can have a shallow container and refill nutrients. To improve the oxygen content of the water, we use an air stone and a pump to make bubbles on the water’s surface. These bursting bubbles will wet the roots with an oxygen-rich nutrient solution.

You could also buy a DWC system that is ready to grow from day one.

mixing nutrients to grow hydroponic?

Cilantro’s nutrient requirements are pretty basic. It’s not a fruiting plant or a root vegetable. We all need cilantro’s green and lush foliage to top our dishes.

Most hydroponic nutrient solutions work for cilantro. I recommend using the master blend 4-18-38 with calcium nitrate and Epsom salt. The below link will get you all three at once.

Here’s how to mix the nutrients.

First, you must ensure your water is pH neutral and its electric conductivity is less than 0.3. RO water would be perfect. However, you should check these parameters if you’re using tap water, well water, or rainwater.

Cilantro and many other plants grow well in the pH range of 5.8-6.5. However, mixing nutrients will make the water slightly acidic, so we start with pH-neutral water.

In hydroponics, you prepare two nutrient solutions and mix them in your actual nutrient container in small quantities. This is because, at high concentrations, some minerals in the nutrient solution may precipitate. Thus, we prepare two solutions, namely part A and part B.

Part A is the Masterblend 4-18-38 (or any NPK + micronutrient fertilizer of your choice) and Epsom salt. Add 2.4 grams of Masterblend and 1.2 grams of Epsom salt for every gallon of water. Finally, mix part B. For simplicity, you can add about 2.4 grams of calcium nitrate to the prepared one gallon of Part A.

This is Masterblend’s tomato formula. When mixed correctly, it gives a nutrient concentration of 2.4 EC. However, it also works for most vegetables and herbs. For instance, you can use this same mix to grow basil.

Related: Nutrient Requirements For Hydroponic Basil: Mixing, Fixing and Diagnosing

How can light be provided to Grow cilantro indoors?

Cilantro thrives in partial shade, which means sunlight for about 4-6 hours daily. This makes cilantro suitable for growing on your window-side or balcony.

Growing cilantro indoors with other plants can be slightly tricky. If the foliage of other plants blocks the light reaching cilantro, it may grow taller and thinner without many leaves. Fortunately, cilantro stems are edible, too. But make sure the plants are spaced enough to get enough light.

There may be instances where the sunlight is insufficient to grow cilantro indoors. Even if your balcony receives 4-6 hours of sunlight, it may not be sufficient due to seasonal variation. In such instances, you can grow cilantro indoors with a grow light.

Again, since we grow cilantro only for its edible leaves, most grow lights can work well. General-purpose T5 LED tubes could also do the job, but a general-purpose light will waste more energy. If you’re serious about growing cilantro indoors, it’s time to invest in a good growlight.

When you grow cilantro indoors with a grow light, you should provide the lighting for at least 8 hours daily. This is true even if you supplement sunlight with a grow light.

Common issues when growing cilantro indoors

The most common issue when growing cilantro indoors is stunted growth. As discussed, the potent reason for this is the lighting. Besides, it can be an issue with the nutrient solution itself. Check the EC and the light level for the plant; if it’s too low, try to improve it.

The next issue is tip burns. Tip burns in cilantro can happen for various reasons, including nutrient overdose. Check the EC to ensure this is the problem. Cilantro can tolerate high concentrations of nutrients, but for very high salt levels, cilantro leaves may burn.

Insufficient airflow can also cause tip burns. Airflow is essential for any plant. It improves the transpiration process, which, in turn, helps the plant’s nutrient uptake. Sufficient airflow is vital to uptake minerals like calcium to the leaf tips. To improve airflow when growing cilantro indoors, use a fan running for at least 6 hours daily.

Related: A Guide to Clean Your Grow Room Fans

Finally, grow lights can also cause tip burns. When they are too close to the plant, the heat produced by the grow lights can cause the leaves to dry and die. This one is easy to spot as only parts close to the light get burned. To avoid it, ensure that the grow lights are at least six inches above the top of the plant.

Summary

This post has extensively discussed growing cilantro indoors and the challenges you might face. We’ve also discussed why the Kratky method is perfect and why you can use DWC.

Growing cilantro has several benefits, but it also has challenges. We’ve addressed some of those issues. Most importantly, the lighting and tip burn issues commonly appear in cilantro plants.

I hope this guide helps you grow bountiful cilantro all year round. Happy growing.