Diagnosing Houseplant Problems from Improper Environmental Conditions

Growing indoor plants is a rewarding hobby that yields beautiful results. But when problems arise with your indoor plants, it can be difficult to determine how to fix them.

When encountering a houseplant problem, ask yourself, Are the environmental conditions appropriate for this species?

If problems arise, start by understanding the needs of that particular species for light, soil, water, humidity, temperature, and fertilizer. If these environmental conditions are not ideal, they must be changed, or the houseplant must be moved to a location where they are ideal.

A single factor does not cause many problems – they result from several factors coming together to cause an unhealthy or unattractive plant. Always look for more than one factor contributing to the issue and correct all of them to solve the problem. It is also important to identify the primary issue. Some problems are caused by other factors, and while you can address the problem, if you don't solve the primary issue, the problem will always return.

Issues Related to Improper Environmental Conditions

Most houseplant issues arise from poor environmental conditions. Improper conditions for houseplants will lead to stress. This also makes the houseplant much more likely to be affected by pests and disease. Changing the conditions in which it grows (light, soil, fertilizer, watering, etc.) to align with that particular species' needs will help solve the issue.

No Flowers

When houseplants are not flowering, it is often because proper environmental conditions are not met.
Investigate the following potential causes and correct them, if needed:

Is it supposed to have flowers? Not all houseplants readily flower indoors or only at certain times of the year.
Ensure it has the appropriate daylength. Some houseplants are photoperiodic and need short or long days to bloom.
Look at the light intensity. Without adequate light, indoor plants won’t bloom. Increase light intensity by moving to a brighter window or introducing supplemental light.
Look at the fertilizer routine. Houseplants that do not receive enough fertilizer during their active growing time (spring and summer) will not bloom as well. Start regular fertilization. Some species will have abundant growth and few flowers when over-fertilized.
Look at temperatures. Some species of houseplants require a temperature drop seasonally (i.e., summer to fall) or a temperature change from day to night to flower.

Brown Leaf Tips

Brown leaf tips or edges can happen on any indoor plant but are common on some species like spider plant and dracaena.
Investigate the following potential causes and correct them, if needed:

Raise humidity levels. This is the most common reason for brown leaf tips. The humidity levels in homes are often low, especially during winter. Utilize a humidifier, pebble tray, terrarium, or group plants to help raise the humidity around the houseplant.
Look at watering practices. Inconsistent watering, in particular allowing plants to dry out too long between waterings, will cause brown leaf tips or edges.
Reduce fertilizer/salt build-up in the soil. Excess salts build up in the soil from too much fertilizer, which can cause brown leaf edges (among other problems). Flush soil, reduce fertilizer rates and frequency, and potentially repot.
Look at water quality. Too much chlorine and other chemicals in the water, such as fluoride, can cause brown leaf tips, especially over an extended period of time on sensitive species like spider plant, ti plant, dracaena, prayer plant, and calathea. Use a different water source if this issue is suspected.

Trimming the brown portions off the leaves with scissors can temporarily improve appearance, but new browning will occur if the original issue is not addressed.

Spindly Growth

Lanky, stretched-out, spindly, and gangly growth may develop over time and create indoor plants that are not attractive. In nearly all cases, once the issue is fixed, new growth will look better, but the previous growth will always look spindly.
Investigate the following potential causes and correct them, if needed:

Increase light levels. The typical cause of spindly growth is low light levels. In many cases, houseplants are not provided enough light. Move to a brighter location or provide supplemental light.
Reduce fertilizer. Too much fertilizer promotes excessive growth that often looks spindly. Reducing fertilizer rates may mean less rapid growth, but what does grow will be more compact and attractive.

Leaf Scorch & Drop

Leaf scorch is analogous to a “sunburn” on the leaves. The damage is permanent and may lead to leaf drop depending on the species.
Investigate the following potential causes and correct them, if needed:

Slowly change to new light intensity. This issue often comes from a quick transition to a very different light intensity. If you move houseplants from inside directly to bright outdoor light, they will scorch and/or drop leaves. Transition plants slowly to new light levels over several weeks.
- Some species, like weeping fig and tropical hibiscus, will drop leaves instead of scorching. Occasionally, this can happen with even a minimal change in light intensity.
- Leaf drop can occur when plants are quickly moved from bright to darker locations.
Check light intensity. Most houseplants are native to shady understory environments. If there is too much light, they may scorch, whether they’ve been transitioned well or not. Reduce the light intensity if needed.

Wilting

Wilting is the result of roots not providing adequate moisture to the leaves and stems. It can be caused by two completely opposite reasons, either under-watering or over-watering, making it difficult to diagnose and solve.
Investigate the following potential causes and correct them, if needed:

Check for dry soil conditions. If the root ball is dry too long or dries out quickly, roots cannot access water, and plants wilt. The soil may be dry because:
- you are not watering frequently enough
- you are not watering thoroughly enough; making sure to wet the entire root volume
- water is not absorbing and is instead running around the dry root ball and down the side of the container
- the container is too small
- the container is porous clay or terracotta and dries out too quickly
- the plant is pot-bound
Check for wet soil conditions. If the root ball is always wet, the roots rot and die. With fewer roots, the plant cannot access enough water and wilt. Always let the soil in containers dry thoroughly between waterings. This wet-dry cycle in the soil keeps indoor plants healthy. The soil may be wet because:
- you are watering too frequently
- there is no drainage hole in the container
- the saucer or outer pot/sleeve is allowed to hold water
- the soil is old and has broken down, becoming more compacted, allowing it to hold more water and less air. Repot in fresh, well-drained soil
- The container is too large, and the large volume of soil takes too long to dry out

Leaf Drop, Yellowing, or Browning

Yellowing, browning, and dropping of leaves are some of the vaguest and most difficult issues to deal with because they can be caused by a wide variety of issues. Know the species and its ideal environmental conditions and make changes to fix the issue.
With so many potential causes, investigate and address them in this order (roughly most straightforward to address to hardest):

Normal leaf shedding. If only a few leaves are dropping and they are older inner leaves on a plant that otherwise looks very healthy, don’t worry about it. Leaves don’t live forever! The shedding of old leaves as the plant grows is normal.
Cold damage from transport. Always box or bag plants anytime these tropical indoor plants are exposed to even a moments-worth of below-freezing temperatures. Minimize the time in the cold car, garage, etc.
Temperature fluctuations. Avoid drafts from doors, heat vents, or windows. Don’t trap plants between the window and curtain, as temperatures change significantly from day to night in this location.
Check watering practices. Conditions that are too wet or too dry can cause leaf drop.
Check fertilizing practices. When plants are under-fertilized, they will often yellow and drop leaves.
Adjust the humidity. The humidity is too low for plants in most homes. Use a humidifier, pebble tray, terrarium, or group plants to help raise humidity.
Check light intensity. Light levels that are too high or too low, as well as a sudden change in light intensity, will cause leaf drop.