If you are planning to grow a coleus plant in your indoor garden or backyard garden, the first step is always finding the best soil for the plant so that it thrives.
It may seem very easy in the beginning, but finding the best soil for the coleus plant is a little tricky when you have literally hundreds of different ingredients available.
But worry not! This article walks you through everything you need to know about the ideal coleus soil mixture, be it signs of using the wrong mixture or different coleus soil mix recipes, we got all covered.
Let’s get started.
Best Soil For Coleus Plant – Quick Answer
Coleus plants thrive in a soil mixture that has good aeration, drainage, enough water holding capability, and high organic content. Most of the general potting soils available online work well for coleus, but try to add a little extra perlite to improve the overall drainage.
Additionally, coleus prefers slightly acidic to neutral soil (5.5 to 7). So, make sure that the soil you buy online is acidic. If not, try to add some activated charcoal or similar component to make it acidic.
Common Ingredients For Coleus Soil Mixture
When you try to find the best soil for coleus plant, it may feel very confusing at the beginning due to the sheer amount of different potting soil and ingredients available on the market.
Even though hundreds of brands are advertising different coleus soil mixtures online, the basic ingredients are always the same.
Here are some of the commonly seen ingredients that you should look for.
1. Peat moss
It is considered to be the gold standard in indoor potting soil and one of the ingredients found in almost all the general potting soil available on the market.
It has the ability to hold water several times its weight and releases it whenever the coleus root demands. Another advantage of peat moss is, that it binds really well with the roots and holds on to the nutrients in the mixture.
Alternatives: Coco coir, Rice hull, etc.
Perlite is a naturally occurring volcanic glass-like stone that expands upon heating.
Similar to peat moss, perlite is also found in most commercial potting soil mixtures. The perlite that is sold commercially is the heated variation of the air-filled natural perlite.
It is utilized as the potting medium for plants like calathea, monstera, coleus, etc because of its highly porous nature. They can enhance the potting soil’s capacity for water drainage and aeration.
Alternatives: Vermiculite, pumice, etc.
3. Pine bark
The outermost layers of trees are generally called bark. They are very light and coarse which makes them a great candidate for improving aeration in the roots and storing moisture.
Mostly, barks from pine and orchids are used in the potting soil mixtures of indoor plants. They can be purchased as a standalone ingredient in different sizes.
Alternatives: Perlite, Rice husk, Vermiculite, etc.
For the optimal growth of plants, the soil must be highly nutritious.
Compost is a mixture of living tissues that are at different stages of their decomposition process. It will include leaves, animal matter, vegetable waste, etc.
Soil mixture containing natural compost will have a foul smell due to the decaying material. Because of this reason, many commercial potting soils skip composts and add chemical fertilizers.
Both have their own advantages and disadvantages. Based on your preference either choose compost or chemical fertilizer recommended for the coleus plant.
Alternatives: Worm castings, cow manure, coffee grounds, leaf molds, etc.
Charcol is nothing but the black residue that is left after burning wood.
Due to its lightweight characteristic, it is a good ingredient in potting soils that needs excellent drainage capability. Additionally, a couple of scientific study states that charcoal has the ability to hold the soil nutrients from leaching away during rain or watering.
Alternatives: shredded cleaves, pine bark, clay, etc.
Coleus Soil Mix Recipes
If you decide to make your own coleus soil mixture, here are a few recommended recipes to try.
- Peat moss (30%) + perlite (30%) + compost (30%) + charcoal (10%)
- Coconut Husk (30%) + Vermiculite (30%) + Leaf Mold (30%) + Pine Bark (10%)
- Peat Moss/Coco Coir (30%) + Pumice (30%) + Worm castings (30%) + Charcol/Pine Bark (10%)
Don’t consider these as hard-coded ratios.
You are free to modify the composition based on the external climate and conditions. For example, if you always overwater your coleus, use a higher percentage of ingredients dedicated for drainage and water holding capability.
While mixing these coles soil mixtures, add small quantities of water in between to make all the ingredients integrate well. Once the soil mixture is ready, it must feel moist, but not soggy.
However, for people who don’t want to mix their own soil mixture, here are some of the good pre-made potting soil available online.
- Miracle Grow Indoor Potting Mix
- Bloomscape Potting Soil
- Espoma Organic potting Mix
If getting your hands on these potting mixtures is not possible due to any reason, try to buy a general-purpose indoor potting mixture from your local garden store.
For pre-made soil mixtures, it is always recommended to add some perlite or vermiculite to improve the drainage and water holding capability.
Signs Of Using Bad Coleus Soil Mix
When you use a bad potting mixture for your coleus plant, the effects will be shown by the plant in the following months. The signs include discoloration of leaves, stunted growth, hard and damp soil, rotten smell, curly and droopy leaves, etc.
Let’s go through each of these signs in detail for a better understanding.
1. Discoloration in leaves
A study published in the Australian Journal Of Soil Research states that whenever a plant is under stress, the corresponding effects will be seen in the leaves.
Discoloration or changing of leaf color is one such way of telling you that the coleus plant is in distress and it’s time for you to analyze and fix it.
The logic behind coleus leaves changing color due to a bad potting mix is pretty straightforward.
The roots of your coleus plant won’t receive enough oxygen and other nutrients to carry out plant functions if it is placed in the incorrect potting soil. The plant consequently begins to lose its bright foliage, turning yellow, then brown.
2. Slow or stunted growth
A lack of nutrients, water, or sunlight will cause your coleus plant to start storing its energy for survival rather than producing new growth.
According to a study that appeared in the Australian Journal of Soil Research, soil structure has an impact on the capacity of roots to expand and supply nutrients and water to leaves.
Even if the roots are now able to absorb enough water and nutrients, if the soil is extremely moist and has a very poor structure, the roots will produce hormonal signals that will prevent the growth of the shoot.
3. Hard and damp soil
Seeing hard and damp soil as a symptom of bad coleus soil mixture is self-explanatory.
Coleus plants prefer coarse soil medium with good drainage and enough holding capability. If your coleus soil is hard and damp even after a few days of watering, then most probably the soil mixture is either wrong or very old that needs to be replaced.
4. Curling and wilting leaves
In contrast to the color change, which causes calathea leaves to turn yellow or brown, this ailment causes them to curl and wilt.
Having curly or wilting leaves is not only a sign of bad coleus soil mixture but also a few other problems like overwatering, underwatering, sunburn, etc. Therefore, before changing the soil only because some of the leaves are curling and wilting, look for the other warning signals.
The last stage before a plant begins to die is typically thought to be the wilting of the leaves.
So, before the plant starts to die, take action.
Best Coleus Soil Mix – Frequently Asked Questions (FAQs)
Choosing the best soil for coleus is one of the topics in many gardening threads where the questions are not answered. And, in this section, we will be answering those questions so that people like you don’t have to wander.
Does coleus do better in pots or ground?
Depending on where you live, you can grow coleus in either pots or ground. Even if your location is ideal for growing in the ground, it is recommended to grow them in containers. It is because of the fact that conditions and environment can be easily altered in container-grown coleus compared to ground-grown ones.
Do coleus plants like acidic soil?
Coleus plants are rated to thrive in slightly acidic soil conditions. The recommended pH range is between 6 and 7. However, a couple of scientific research finds that they do just fine in soil having pH up to 5.5 and as low as 7.5 making them adaptable.
Can I use miracle grow for coleus?
Miracle Grow is an expert-recommended ready-made potting soil mixture for indoor plants including coleus. Depending on your watering routine, humidity and temperature, you may have to add extra perlite to control moisture in the mixture for your coleus plant.
Is charcoal good for coleus?
Charcoal is a good ingredient for your coleus soil to preserve the nutrients. Scientifical evidence says that charcoal has the ability to prevent the nutrients from leaching through the drainage holes during watering or rain. If you plan to grow your coleus ion outdoors, then adding a part of charcoal is highly recommended.
Can I use cactus soil for coleus?
It is not recommended to use cactus soil for coleus since they are too sandy and lacks enough water-holding capability. Additionally, the roots of coleus plants cannot hold on to the sandy structure of cactus soil.
Choosing the ideal soil mixture is the first step toward the successful growth of your coleus plant.
Although coleus plants will grow just fine in any all-purpose potting soil out there, we recommend you to mix your own mixture using ingredients like peat moss, pine bark, perlite, and a slow-release fertilizer.
Once you plant them in a soil mixture that they love, you will start noticing the plant’s real potential in terms of beauty in foliage.
To back up the information we provide in our articles, the Plantials team only uses high-quality sources published in peer-reviewed university or scientific research journals.
- Coleus Species: Solenostemon Scutellarioides, Review Article From Inventi Journal Via Reasearchgate.
- Performances Of Coleus On An Acid Mineral Soil In Bengkulu, Unib Scholar Repository.
- Evaluation Of Soil Characteristics And Yield Variation Of Coleus (Coleus Forskohlii) In Different Agro-Climatic Zones Of Tamil Nadu, India, International Journal Of Chemical Studies.
- Research on Soil Acidity in Agriculture Victoria Journal, Australia.