What To Do When Your Coleus Isn’t Growing

Coleus is a beautiful plant perfect for adding color and texture to your garden. It’s low maintenance, drought tolerant, and best of all—it thrives in warm weather. So what do you do if your coleus isn’tp growing? 

When your coleus isn’t growing, you should attend to its basic needs and see if something is amiss. Take a look at pH, temperature, sunlight, watering, and pests to determine if there’s something you can do to help it. You may also adjust your practices and see how your coleus grows or changes. 

It’s frustrating when your plants don’t grow, and it can be disheartening when your vivid coleus plants are stunted and sparse. Below, I’ll go over your step-by-step process for troubleshooting plants. We’ll also talk about the ideal conditions for your coleus plant and how to ensure your coleus plants thrive. 

How To Promote Coleus Plant Growth

If your coleus isn’t growing, you may feel impatient. Plants growing slowly, outside the range of their typical growth patterns, usually do so because they lack a basic need that helps them grow.

When your coleus plants aren’t growing, you should ensure the following factors. 

Create the Ideal pH for Your Coleus Plants

It prefers slightly acidic soil with a pH between 5.0 and 6.5, so you can test the soil on your plant before planting it to see if it needs any adjustments. 

You can also add peat moss or peat humus to help balance the soil’s acidity level—just don’t use too much, or else your water will turn brown! Liming is also helpful for gardens to support achieving the correct pH. Composting and mulching are also terrific ways to keep pH balanced. 

Create Ideal pH for Your Coleus Plants

Coleus plants need different amounts of water depending on where they are. Outside, they’ll need more water (in hot climates, they may need it as much as twice a day), but inside they only need it once a week. The idea is to ensure the top inch of your soil is always moist or damp but never soaking wet

If you are only watering a little at a time, and the water on top is still flooding, then you need to look at your plant’s drainage. Make sure your pot has drainage holes and let the soil dry a little before watering again, as overwatering is one of the most common causes of death for coleus plants. Keep these things in mind when it comes to watering: 

  • Check to make sure your pot has drainage holes.
  • Let the soil dry a little before watering again.
  • Don’t overwater or let your soil get soggy. If you find waterlogging or soil compaction, your drainage has a problem.

A moisture meter is an excellent tool for assessing whether or not your coleus needs more water. 

Ensure Correct Sunlight and Temperature for Coleus Plants

I think the most common issue when it comes to coleus is sunlight and temperature (and this tends to be the surprise problem behind many growth issues, actually!). Your coleus plants need full sun. Growing them indoors requires a big sunny window and possibly even moving them to the other side of your house for more sun once they’ve lost it in their window.

In the Summer, your coleus plants prefer an average temperature of 60°F (15.55°C). Anything above this may stress them and make them harder to grow. This preference doesn’t mean it is impossible to grow them in warmer climates or the summer—just ensure to use a shade and keep them hydrated. 

Avoid Overcrowding Your Coleus Plants

If you’ve got too much of a good thing, it’s time to thin out your plants. Overcrowding can lead to too much competition for nutrients and other problems such as fungal disease. 

If the leaves turn yellow and fall off, this is a sign that there’s not enough light getting through the plant because there are too many leaves blocking its path. 

This problem can also happen if roots aren’t able to breathe properly due to being packed together tightly in small containers without adequate drainage holes.

Overcrowding may also result in root rot if your soil gets too wet or cold—rooting plants like coleus will be unable to thrive if they’re sitting in soggy or freezing soil!

Overcrowding may indicate that it’s time to clip, propagate, or move your coleus plants to a bigger space. Coleus is usually propagated from cuttings of healthy plants or by rooting stem sections in water for several weeks until roots form at the nodes (joints). 

You can also root coleus stems directly into a moist potting mix, but this method takes longer than cuttings. 

To start new plants from seed, sow seeds indoors six weeks before transplanting outside after all danger of frost has passed; germination should occur within three weeks if conditions are right (70 °F or 21 °C).

Prevent Coleus Plants Pests & Diseases 

We’ve already gone into this a bit, but fungus and pests are probably one of the first things you’ll notice during the troubleshooting process if they’re your problem. Coleus is susceptible to a few common pests and infestations, such as the following:

  • Foliar nematodes. These destructive worms live in the water film on leaves starting on the underside of leaves and progressing through the entire plant.
  • Cyclamen Mites. These tiny mites affect the new growth and buds of coleus plants preventing proper growth.
  • Mealybugs. These insects drain a plant’s resources and appear on leaves and leave white cottony masses on plants. 
  • Two-spotted spider mites. These mites are particularly drawn to the coleus plants and attack their leaves, causing yellowing and stunted growth
  • Whiteflies. These tiny moth-like creatures often infest coleus. The larvae suck the sap from the undersides of plants and secrete honeydew which may promote mold growth and attract other pests. 
  • Aphids. These soft-bodied insects drain plant nutrients and can cause stunted growth and plant death. 

What To Do if You Find Fungus or Pests 

Moldy soil is often an indicator that you’re either overwatering, your soil is compacted (pressed down so heavily there’s no room for water to move around), or your plant isn’t getting proper draining. 

If you’ve found mold or fungus, fix your watering issues first. It may be the soil you used (peat moss gets pretty compacted very easily) or the pot you have it in. Then, once you fix the watering issue, you can use a fungicide to clean up your plants.

For pests, I swear by neem oil. It’s safe, organic, and helps pests stay off your coleus plants. For more information on how to use neem oil, you can read my other article: Should You Rinse Neem Oil Off Plants?

How Long Should It Take for My Coleus To Grow?

Coleus plants can be demanding, and if you’ve never grown them before, you may now know what to expect. You may just need to be patient with your coleus rather than begin troubleshooting or problem-solving processes. 

The life cycle of your coleus plant is over forty days long. After planting, it can take 21 days for your coleus seeds to germinate. After that, you’re looking at least 3 to 4 weeks (or one month) before it grows larger. It should be 1-3 ft (30.5-91 cm) tall in maturity, depending on the type. 

If your coleus is still in this growth window, give it some patience and time to get to its mature size. Keep up your good work (following the guidance above for coleus’ ideal conditions), and get ready for your coleus to bloom!

If you would like to learn more about coleus plant growth, please read my article: Does a Coleus Plant Come Back Every Year?


Coleus is a beautiful plant with vibrant blues and purples to make your garden come to life. If you’re having trouble growing them and want to learn more about how to keep them healthy, troubleshoot their pH, watering, sunlight, temperature, and nutrients. Keep in mind their life cycle and be patient with your coleus plant if necessary.

Alexander Picot

Alexander Picot is the principal creator of TheGrowingLeaf.com, a website dedicated to gardening tips. Inspired by his mother’s love of gardening, Alex has a passion for taking care of plants and turning backyards into feel-good places and loves to share his experience with the rest of the world.

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