Indigofera: A Comprehensive Guide to Growth and Care

Discover the captivating world of Indigofera 🌿 – Explore the taxonomy, history, and uses of this unique plant!

Table Of Contents show

Indigofera Taxonomy

  • Kingdom: Plantae (Plants)
  • Phylum: Angiosperms (Angiosperms are flowering plants.)
  • Class: Eudicots (Eudicots are a major group of flowering plants with two seed leaves.)
  • Order: Fabales (Fabales is the order of flowering plants to which Indigofera belongs.)
  • Family: Fabaceae (Fabaceae is the family of flowering plants that includes various legume species, to which Indigofera belongs.)
  • Genus: Indigofera (Indigofera is the genus encompassing various species of this plant.)
  • Species: Various (There are numerous species within the genus Indigofera, each with its own unique characteristics.)



Indigofera, also known as true indigo, is a group of flowering plants that holds significant historical and cultural importance. This versatile plant has been cultivated for centuries and has played a crucial role in various ancient civilizations.

From providing vibrant blue dyes to serving as a medicinal herb, indigofera has made its mark on numerous industries throughout history.

Indigofera is a member of the legume family, Fabaceae, and is native to Asia and Africa. It has been used extensively by civilizations such as the ancient Egyptians, Romans, and Greeks.

The cultivation of indigofera for its dye became a thriving industry in India, with the birth of the powerful Indus Valley civilization. The dye derived from indigofera was highly prized and traded worldwide, making it a valuable commodity.

Today, indigofera continues to be cultivated for its ornamental beauty as well as its practical uses. Its attractive foliage and clusters of vibrant flowers make it a charming addition to any garden.

Furthermore, the dye extracted from indigofera is still used in the textile industry, as well as in traditional medicine for its various therapeutic properties. In this article, we will explore the diverse aspects of indigofera, from its historical significance to its cultivation and care.

Whether you are a gardening enthusiast, a history buff, or simply seeking to learn more about this fascinating plant, this comprehensive guide will provide you with all the information you need for successful indigofera cultivation and maintenance.

The Historical Significance of Indigofera

Indigofera holds a significant place in history, with its origins dating back thousands of years. This versatile plant has been cultivated and utilized by various civilizations for its rich blue dye, making it a valuable commodity.

One of the earliest records of indigo dye production comes from ancient Egypt, where it was used to color textiles and create vibrant fabrics that were highly sought after.

The Indus Valley civilization, located in present-day Pakistan and India, also had a flourishing indigo industry, producing high-quality indigo dye that was traded and exported to other regions.

In addition to its dye-producing properties, indigofera has played a role in traditional medicine. Its leaves and roots have been used as natural remedies for a range of ailments, including skin conditions, fevers, and digestive issues.

The medicinal properties of indigofera were recognized by various ancient cultures, including the Greeks and Romans, who used it to treat a variety of ailments.

The historical significance of indigofera goes beyond its practical applications. It has been used symbolically in many cultures, representing wealth, power, and spirituality.

In some ancient civilizations, indigofera was associated with divinity and used in religious rituals and ceremonies. Its deep blue hue was often seen as a symbol of purity and divine connection.

Indigofera’s historical relevance is a testament to its enduring value and versatility. From its role in trade and commerce to its use in traditional medicine and symbolic significance, indigofera has left an indelible mark on human history.

Different Varieties of Indigofera and Their Characteristics

Indigofera, a diverse genus of flowering plants, boasts several varieties that capture the eyes and hearts of both garden enthusiasts and nature lovers. Each variety has its own unique characteristics, offering a range of colors, sizes, and growth habits to suit various preferences and gardening conditions.

1. Indigofera tinctoria: Also known as True Indigo or Common Indigo, this variety is famous for its history in dye production. With vibrant blue-purple flowers and a height of up to three feet, it adds a striking pop of color to any garden. Moreover, its leaves serve as an important source of indigo dye, making it a popular choice for both ornamental and utilitarian purposes.

2. Indigofera gerardiana: Commonly referred to as Gerard’s Indigo, this variety is native to the Himalayas and Afghanistan. It features delicate pink flowers that bloom in clusters, creating a mesmerizing visual spectacle. Gerard’s Indigo is known for its ability to survive in harsh, arid climates, making it an excellent choice for xeriscape gardens or regions with limited water availability.

3. Indigofera australis: Native to Australia, this enchanting variety is commonly called Australian Indigo. Its pale pink flowers, arranged in elongated clusters, exude a captivating elegance. Australian Indigo thrives in a variety of soil types and is well-suited for coastal gardens, as it is tolerant of salt spray and coastal breezes.

4. Indigofera amblyantha: With its stunning crimson flowers and ability to attract pollinators, such as butterflies and hummingbirds, Indigofera amblyantha, or Red Indigo, is a cherished variety for many gardeners. This perennial shrub can reach heights of up to six feet and adds a vibrant touch to any landscape.

5. Indigofera pseudotinctoria: Also known as Himalayan Indigo, this variety is valued for its medicinal properties. Growing to about four feet tall, it produces pale pink to lavender flowers. Its stems and leaves contain properties that have long been used in traditional medicine for their anti-inflammatory and wound-healing effects.

These are just a few of the myriad varieties available within the Indigofera genus. Whether you seek a bold splash of blue, a delicate blush of pink, or a plant with beneficial properties, there is an Indigofera variety that will complement your garden and captivate your senses.

Choosing the Right Location for Your Indigofera Plant

Indigofera plants thrive best in full sunlight, so it is crucial to choose a location that provides them with at least six to eight hours of direct sunlight each day. Look for an open area in your garden or yard that is not shaded by trees or buildings.

This will ensure that your Indigofera plants receive the necessary amount of light for optimal growth and blooming.

In addition to sunlight, it is important to consider the space requirements of Indigofera plants.

These plants can grow quite tall and wide, so you should choose a location that allows enough room for them to spread out. Ensure that there is ample space around the plants, as overcrowding can hinder their growth and reduce air circulation, leading to potential diseases or pests.

Be mindful of nearby structures or other plants that may obstruct the growth of your Indigofera, and place them in an area where they can freely expand without any hindrances.

When selecting the right location for your Indigofera plant, it is also essential to consider the soil conditions. Keep reading to learn about the specific soil requirements for successful Indigofera growth.

Soil Requirements for Successful Indigofera Growth

When it comes to growing Indigofera plants, selecting the right soil is crucial for their success. These plants thrive in well-draining and slightly acidic soil conditions. Ideally, the pH level should range between 5.0 and 6.5 for optimal growth. If your soil is too alkaline, you can add amendments like peat moss or pine needles to lower the pH.

In addition to the pH level, it’s important to choose soil that is rich in organic matter. This helps retain moisture while allowing excess water to drain away, preventing the roots from becoming waterlogged.

Organic matter also provides essential nutrients for the plants’ growth and development. You can improve the organic content of your soil by adding compost or well-rotted manure. Mixing these amendments thoroughly with the existing soil will create a nutrient-rich environment that Indigofera plants will thrive in.

How to Plant Indigofera Seeds or Seedlings

Planting indigofera seeds or seedlings is a straightforward process that can be done by anyone, whether you have prior gardening experience or not. To ensure successful growth and development of your indigofera plants, follow the steps below:

1. Prepare the soil: Start by selecting a location that receives full sun and has well-draining soil. Indigofera plants thrive in slightly acidic to neutral soil with a pH range of 6 to 7. If needed, amend the soil with organic matter such as compost to improve its fertility and drainage.

2. Dig the hole: If you’re planting indigofera seeds directly in the soil, dig a small hole about 1 inch deep and place the seeds inside. Space them at least 12 inches apart to allow enough room for growth. If you’re using seedlings, dig a slightly larger hole that accommodates the root ball of the young plant.

3. Plant the seeds or seedlings: Gently place the seeds or seedlings in the prepared holes, making sure they are at the correct depth. Cover the seeds with soil, pressing it down lightly to ensure good soil-to-seed contact. For seedlings, backfill the hole with soil, firming it gently around the roots.

4. Water thoroughly: After planting, give your indigofera seeds or seedlings a good soak by watering them deeply. This helps to settle the soil and provides the necessary moisture for germination or root establishment. Keep the soil consistently moist but not waterlogged during the initial stages of growth.

5. Mulch and protect: To conserve moisture and suppress weed growth, apply a layer of organic mulch around the base of the indigofera plants. This also helps to regulate soil temperature and acts as a natural fertilizer as it breaks down over time. Protect your newly planted indigofera from extreme weather conditions and pests, such as rabbits, by using netting or wire mesh if necessary.

Essential Watering Techniques for Indigofera Plants

When it comes to watering your Indigofera plants, it is important to strike the right balance. Overwatering can lead to root rot and other diseases, while underwatering can cause stress and hinder growth.

Therefore, understanding the essential watering techniques for Indigofera plants is crucial for their overall health and vitality.

First and foremost, it is important to note that Indigofera plants prefer well-draining soil. This means that excessive moisture should be avoided, as it can suffocate the roots.

To ensure proper drainage, consider adding organic matter or vermiculite to the soil before planting your Indigofera. This will help with water retention without causing waterlogging.

During the initial planting and establishment phase, it is recommended to water the Indigofera plants thoroughly and deeply. This will encourage the roots to spread out and establish a strong foundation. Afterward, adjust your watering routine according to the weather conditions.

In hot and dry climates, regular watering may be necessary, while in cooler and more humid environments, you can decrease the frequency. However, always keep an eye on the soil moisture and adjust accordingly.

It is important to water your Indigofera plants at the base, close to the roots, rather than from above. This will prevent excessive moisture on the foliage, which can lead to fungal diseases.

Additionally, watering in the morning or evening is recommended, as it allows the plants to absorb the water effectively and reduces the risk of evaporation from direct sunlight.

Remember, every plant has different watering needs, so observe your Indigofera plants closely and adjust your watering routine accordingly. By providing them with the right amount of water at the right time, you will ensure their optimal growth and vibrant blooms.

Fertilizing Indigofera: Tips and Recommendations

When it comes to fertilizing Indigofera plants, there are a few key tips and recommendations that can help ensure optimal growth and vibrant blooms. Firstly, it is important to choose a well-balanced fertilizer that contains a good mix of essential nutrients. Look for fertilizers with a balanced NPK ratio, such as 10-10-10 or 14-14-14, as these will provide a good foundation for overall plant health.

To apply the fertilizer, spread it evenly around the base of the plant, making sure to avoid direct contact with the leaves or stems. Gently work the fertilizer into the top layer of soil, being careful not to disturb the roots.

In terms of frequency, it is generally recommended to fertilize Indigofera plants every 4 to 6 weeks during the active growing season, which is typically spring to early fall. However, be mindful of over-fertilizing, as this can lead to excessive foliage growth at the expense of flower production.

In addition to regular fertilization, it is also beneficial to supplement the soil with organic matter, such as compost or well-rotted manure. This will not only enrich the soil with nutrients but also improve its structure and water-holding capacity.

Remember to water the plants thoroughly after fertilizing to ensure proper nutrient uptake. By following these tips and recommendations for fertilizing Indigofera plants, you can help support their overall health and development, resulting in a stunning display of flowers.

Pruning and Trimming Indigofera for Optimal Growth

Pruning and trimming are essential tasks for maintaining the optimal growth of your Indigofera plants. Regular pruning helps promote healthy and vigorous growth, improves air circulation, and enhances the overall aesthetic appeal of the plant. When done correctly, pruning can also prevent the plant from becoming overgrown and tangled, allowing for stronger and more abundant blooms.

Before you start pruning, it’s important to understand the specific requirements of your Indigofera variety. Some varieties may have different growth habits and flowering patterns, which will influence the pruning technique you should adopt.

Generally, pruning should be done in the spring or early summer when the plant is actively growing. It’s also advisable to prune after the plant has finished blooming to avoid removing potential flower buds.

Dealing with Common Pests and Diseases in Indigofera Plants

Indigofera plants, like any other vegetation, are susceptible to various pests and diseases that can hinder their growth and health. It is crucial for gardeners and plant enthusiasts to be aware of these common issues and take appropriate measures to prevent or address them.

Here are some of the most prevalent pests and diseases that may affect Indigofera plants, along with tips on how to deal with them effectively.

1. Aphids: These tiny insects are a common menace for Indigofera plants. They suck the sap from the leaves and stems, causing deformity, yellowing, and stunted growth.

To control aphid infestation, try spraying a mixture of dish soap and water onto the leaves, which suffocates the pests. Alternatively, beneficial insects like ladybugs can be introduced to the garden to naturally prey on aphids.

2. Powdery Mildew: Powdery mildew is a fungal disease that manifests as a white, powdery substance on the leaves and stems of plants. It thrives in humid conditions and can weaken the Indigofera plant.

To prevent powdery mildew, ensure proper air circulation around the plant by providing adequate spacing, trimming overcrowded branches, and avoiding overhead watering. Fungicidal sprays and organic remedies like neem oil can also help control the spread of powdery mildew.

3. Spider Mites: These minuscule arachnids are notorious for their ability to rapidly reproduce and cause damage to Indigofera plants. Spider mites feed on plant leaves, leaving behind tiny yellow spots and webbing.

To combat spider mite infestations, regularly inspect the undersides of leaves for any signs of webbing or discoloration. Remove affected leaves and, if the infestation is severe, consider applying horticultural oil or soap sprays to control their population.

4. Root Rot: Root rot is a common fungal disease that affects the roots of Indigofera plants. Overwatering, poorly drained soil, or improper watering techniques can lead to root rot. Signs of root rot include wilting, stunted growth, and a foul odor emanating from the soil.

To prevent root rot, ensure that the soil is well-draining and avoid overwatering. Applying a fungicide can help in controlling the disease, but it is crucial to address the underlying issues to prevent further occurrences.

Propagation Methods for Expanding Your Indigofera Collection

One of the most rewarding aspects of gardening is the ability to propagate and expand your plant collection. When it comes to Indigofera, there are several effective propagation methods that you can utilize to grow new plants and increase your collection. Let’s take a closer look at some of these methods.

1. Seed Propagation: Propagating Indigofera from seeds is a simple and cost-effective method. Collect mature seeds from your existing plants and sow them in well-draining soil.

Start by scarifying the seeds (lightly scratching the seed coat to aid germination) and soak them in warm water overnight. Then, plant the seeds in seed trays or small pots filled with a mixture of compost and perlite.

Keep the soil consistently moist, and within a few weeks, you should start to see tiny seedlings emerge.

Once the seedlings have developed a strong root system and a few sets of true leaves, they can be transplanted into larger containers or directly into the garden.

2. Stem Cutting: Another popular method of propagation for Indigofera is through stem cuttings. Select healthy, non-flowering stem cuttings from your established plants. Ideally, choose young, green stems that are free of disease or damage.

Using clean and sharp pruning shears, cut a 6-8 inch (15-20 cm) section of the stem just below a node. Remove the lower leaves, leaving only a few sets of leaves at the top.

Dip the cut end of the stem in a rooting hormone powder to encourage root formation.

Plant the cutting in a container filled with a well-draining rooting medium, such as a mixture of sand and peat moss.

Keep the cutting in a warm and humid environment, and mist the leaves regularly to prevent dehydration.

After several weeks, roots should start to form, indicating successful propagation. At this point, you can transfer the cutting into a larger pot or directly into the garden.

By utilizing these propagation methods, you can quickly and effectively expand your Indigofera collection. Whether you choose to start from seeds or take stem cuttings, proper care and patience are key to successful propagation. With time, you will be rewarded with a thriving collection of Indigofera plants that will bring beauty and color to your garden.

Overwintering Indigofera Plants: Tips for Cold Climates

As the colder months approach, it’s important to ensure that your indigofera plants survive the winter and remain healthy for the next growing season. Here are some valuable tips on how to successfully overwinter your indigofera plants in cold climates.

Firstly, it’s crucial to choose the right location for your plants during the winter months. Indigofera plants prefer full sun, so find a spot in your garden that receives ample sunlight even during the winter. This will help the plants retain some warmth and prevent freezing.

Next, prepare the soil around the indigofera plants by adding a layer of mulch. This will protect the root system from extreme cold temperatures and minimize the risk of frost damage.

Be sure to use organic mulch, such as straw or wood chips, and spread it evenly around the base of the plants. This layer of insulation will help regulate the temperature and keep the plants protected during freezing conditions.

In addition to mulching, consider covering your indigofera plants with a protective fabric or sheet during freezing nights. This extra layer will provide an additional barrier against the cold and help retain some heat around the plants. Make sure to secure the fabric tightly to prevent it from blowing off in strong winds.

It’s also important to avoid overwatering your indigofera plants during the winter. While they still need some moisture, excessive watering can lead to root rot or other fungal diseases, especially in colder temperatures. Water the plants sparingly, only when the soil feels dry to the touch, and allow for proper drainage to prevent waterlogging.

Lastly, keep an eye out for any signs of frost damage on your indigofera plants. If you notice discolored or shriveled leaves, it’s a sign that the cold temperatures have affected your plants. Trim off any damaged foliage and branches to promote new growth in the spring.

Indigofera Plant Maintenance: Regular Tasks and Check-ups

Regular maintenance is essential to ensure the healthy growth and vitality of your indigofera plants. By incorporating a few simple tasks into your gardening routine, you can keep your indigofera plants thriving and flourishing.

One important task in maintaining indigofera plants is regular watering. These plants have moderate water requirements and should be watered consistently to prevent the soil from drying out completely.

However, be cautious not to overwater, as excessive moisture can lead to root rot and other issues. It is best to check the moisture level of the soil using your finger before watering. If the top inch of the soil feels dry, it is time to water. Using a watering can or a hose with a gentle spray, water the base of the plant until the soil is evenly moist.

Another crucial aspect of indigofera plant maintenance is fertilizing. Indigofera plants benefit from regular feeding to provide them with the necessary nutrients for healthy growth and vibrant blooms. Use a balanced, slow-release fertilizer specifically formulated for flowering plants.

Apply the fertilizer according to the package instructions, typically every 4-6 weeks during the growing season. Be careful not to apply too much fertilizer as it can lead to excessive foliage growth at the expense of blooms. Always water the plants after fertilizing to ensure proper absorption of nutrients.

Regular check-ups are also important for indigofera plants. Take the time to inspect the plants for any signs of pests or diseases. Common pests that can affect indigofera include aphids, spider mites, and caterpillars.

If you spot any infestations, you can try using organic insecticidal soap or neem oil to control them. Additionally, keep an eye out for any yellowing or wilting leaves, spots, or mold growth, as these may indicate fungal diseases. Promptly address any issues you notice to prevent them from spreading and affecting the overall health of your indigofera plants.

Showcasing the Beautiful Blooms of Indigofera: Flowering Season Tips

Flowering season is an exciting time for Indigofera enthusiasts, as it is when these plants reveal their stunning blooms. Indigofera plants typically produce an abundance of vibrant, colorful flowers that add beauty and charm to any garden or landscape. To fully showcase the splendor of the blooms, here are some essential tips to consider.

First and foremost, ensure that your Indigofera plants are receiving adequate sunlight. These plants thrive in full sun, so choose a location in your garden that receives at least six to eight hours of direct sunlight each day.

The ample sunlight will encourage healthy growth and abundant flowering. Additionally, it is essential to provide your Indigofera plants with well-drained soil that is rich in organic matter. This will create the ideal growing environment and promote vigorous bloom production.

To further enhance the blooming of your Indigofera plants, consider applying a bloom-boosting fertilizer during the flowering season. Look for a fertilizer with a balanced ratio of nutrients, such as a 10-10-10 or 12-12-12 formulation, to provide the necessary nutrients for optimal flower formation.

Be sure to follow the instructions on the fertilizer package for proper application rates and timing.

As the flowering season progresses, regularly inspect your Indigofera plants for any signs of pests or diseases. Common pests that may attack these plants include aphids, mealybugs, and spider mites.

If detected, promptly treat the affected plants with an appropriate insecticide or miticide to prevent further damage. Similarly, keep an eye out for any signs of fungal or bacterial diseases, such as leaf spot or root rot.

Proactive measures, such as proper watering, good air circulation, and regular pruning, can help minimize the risk of disease development.

Troubleshooting Common Issues in Indigofera Care.

Indigofera plants are generally hardy and low-maintenance, but like any other plant, they can encounter some problems along the way. By being aware of these common issues and knowing how to troubleshoot them, you can ensure the health and vitality of your Indigofera collection.

One common issue faced by Indigofera plants is leaf yellowing. If you notice that the leaves of your plants are turning yellow, it could be an indicator of nutrient deficiency, particularly nitrogen.

To remedy this, you can apply a balanced fertilizer with a higher nitrogen content or incorporate organic matter into the soil. Regularly monitoring the nutrient levels in the soil can help prevent this issue from occurring.

Another issue that can affect Indigofera plants is pest infestation. Common pests that can target these plants include aphids, spider mites, and whiteflies.

To combat these pests, you can use natural insecticides or introduce beneficial insects like ladybugs to your garden. Regularly inspecting your plants for any signs of infestation and taking prompt action can help keep these pests at bay.


What is the historical significance of Indigofera?

Indigofera has been historically significant as it was once a primary source of indigo dye, which was highly valued for its use in textile production.

How many varieties of Indigofera are there?

There are numerous varieties of Indigofera, with some popular ones including Indigofera tinctoria, Indigofera suffruticosa, and Indigofera australis, each with their own unique characteristics.

What factors should I consider when choosing a location for my Indigofera plant?

When choosing a location for your Indigofera plant, consider factors such as sunlight exposure, soil drainage, and protection from strong winds.

What type of soil is best for successful Indigofera growth?

Indigofera plants thrive in well-draining soil that is rich in organic matter. A slightly acidic to neutral pH level is preferred.

How do I plant Indigofera seeds or seedlings?

To plant Indigofera seeds, sow them in well-prepared soil and lightly cover them with a layer of soil. For seedlings, dig a hole slightly larger than the root ball and gently place the seedling, filling the hole with soil.

What are some essential watering techniques for Indigofera plants?

Indigofera plants prefer regular, moderate watering. Avoid overwatering to prevent root rot, and water at the base of the plant to minimize the risk of foliage diseases.

What are some tips and recommendations for fertilizing Indigofera plants?

It is recommended to fertilize Indigofera plants in early spring with a balanced, slow-release fertilizer. Avoid excessive nitrogen fertilization, as it can lead to excessive foliage growth at the expense of flowering.

How should I prune and trim Indigofera for optimal growth?

Pruning Indigofera should be done in early spring to remove dead or damaged branches and to shape the plant. Avoid heavy pruning, as it can reduce the plant’s ability to produce flowers.

What are some common pests and diseases that affect Indigofera plants?

Indigofera plants can be susceptible to pests such as aphids, spider mites, and caterpillars. Diseases such as powdery mildew and root rot can also affect these plants.

What are some propagation methods for expanding my Indigofera collection?

Indigofera can be propagated through methods such as seed propagation, stem cuttings, or division of established plants. Each method has its own requirements and success rates.

How can I overwinter Indigofera plants in cold climates?

In cold climates, it is important to protect Indigofera plants from freezing temperatures by providing mulch around the base of the plant and covering it with a protective barrier, such as burlap.

What regular tasks and check-ups should I perform for Indigofera plant maintenance?

Regular tasks for Indigofera plant maintenance include checking for signs of pests or diseases, removing any weeds, and ensuring proper watering and fertilization.

What are some tips for the flowering season of Indigofera plants?

To encourage blooming, ensure that Indigofera plants receive sufficient sunlight and are not over-fertilized. Deadheading spent flowers can also promote continuous blooming.

What are some common issues that may arise in Indigofera care?

Common issues in Indigofera care may include yellowing leaves, lack of flowering, pest infestations, or fungal diseases. Identifying and addressing these issues promptly is key to maintaining plant health.

Why are my Indigofera leaves turning yellow?

Yellowing leaves in Indigofera can be caused by various factors such as nutrient deficiencies, overwatering, or poor drainage. Assess the plant’s growing conditions and adjust accordingly.

What should I do if my Indigofera plant is not flowering?

If your Indigofera plant is not flowering, ensure it receives adequate sunlight, is not over-fertilized, and is pruned properly. Additionally, some varieties may have specific flowering seasons.

How can I control pests on my Indigofera plants?

To control pests on Indigofera plants, use organic insecticidal soaps, neem oil, or introduce beneficial insects like ladybugs or lacewings. Regular inspection and early intervention are crucial.

How do I prevent powdery mildew on my Indigofera plants?

To prevent powdery mildew on Indigofera, ensure proper air circulation, avoid overhead watering, and remove any infected plant material. Fungicidal treatments may also be necessary.

Can I grow Indigofera indoors?

While Indigofera plants prefer outdoor conditions with ample sunlight, some compact varieties may be suitable for indoor cultivation. Ensure they receive adequate light and appropriate care.

Can I grow Indigofera in containers?

Yes, Indigofera can be grown in containers, provided they have sufficient depth for root development and good drainage. Choose smaller varieties and use well-draining potting soil.