Ultimate Handbook of Indoor Plant Care

In this guide, you will learn basic indoor plant care. Knowledge of what individual plants need for healthy growth will help you revive your green thumb.

I will teach you everything you need to know about indoor plant care from basic light, water, humidity requirements to how and when you should repot your indoor plant and even how to treat and prevent those nasty spider mites that are crawling around your precious’s plant baby!

Over the past twenty years houseplants have grown in popularity and is both a popular hobby and an interior decorating technique.

More than 75 percent of all American families use living plants as part of their home decor or cultural expression.

Close observation, practice, and knowledge are the keys to successful indoor plant care, some people even call it good plant housekeeping. 

You can find houseplants offered in a wide variety of sizes, shapes,  colors and textures that will beautify your home and help soften our environment.

They have been scientifically proven to improve our health by lowering blood pressure and removing pollutants from the air we breathe. 

A houseplant is simply an outdoor plant that is grown indoors. Not all plants are suitable for indoor culture.

Some require environmental conditions that are impossible to duplicate indoors.

Others adapt to indoor culture if their minimum growth requirements are provided. The key to successful indoor plant culture is to select plants that are adaptable to the conditions in your home.

The normal home provides a number of different environments. Light varies from sunny windows to dim corners.

Plants in living areas receive long hours of light (either natural or artificial) year-round, but those in bedrooms normally receive only minimal supplemental light.

Humidity usually is much higher in kitchens and bathrooms than in living rooms. Temperatures vary widely.

The overall climate may range from humid subtropical to arid desert in various locations.

To keep plants healthy and attractive, you must control a number of environmental factors such as light, temperature, humidity, water, and plant nutrients.

The right combination results in healthy plants. Too much or too little of any factor results in poor plant health or death.

Which Plant Should You Buy?

Shopping for Houseplants

Houseplants can be purchased at many flower shops, greenhouses, garden centers, supermarkets, and department stores. Many plants are grown in local greenhouses and others may come from great distances. 

When you are shopping for houseplants, be sure to inspect the plant and pot closely. Watch for brown edges and spindly growth with elongated stems and large gaps between new leaves.

A healthy plant will have green, brightly colored, crisp leaves, moist soil, new growth, and a vigorous root system.

Avoid plants with drooping or yellowing leaves, bone-dry soil, a spindly shape, and signs of pests or disease.

Signs of a pests could include very fine webs, small cottony bumps, shiny or sticky droplets, or tiny black spots. Don’t forget to check on or under leaves and between branches and leaf veins. 

Check any support stakes to make sure they are not hiding broken stems or branches. 

Finally, make sure the plant is placed in an area that suits its optimal requirements for light, temperature  and humidity. 

Where to Place Your House Plants  

With the exception of the very darkest areas, you can always find a houseplant with growth requirements  to match the environmental conditions in your home.

The most important factors are light intensity and  duration. The best way to determine the intensity of light at a window exposure area is to measure it with a  light meter.

A light meter measures light in units called foot-candles. One foot-candle is the amount of light  from a candle spread over a square foot of surface area.  

Plants that prefer low light may produce dull, lifeless-looking leaves when exposed to bright light. Bright  light can also cause leaf spots or brown-tipped scorched margins.

Conversely, not enough light can cause  slow, spindly growth and the development of small pale leaves.

Plants may not flower. If they do, the buds may drop or the flowers may fade quickly. Variegated leaves often revert to being completely green. 

What even is bright indirect light?

Lighting and Window Exposure

When arranging indoor plants in your  home, consider the plant lighting needs. 

Some plants require lots of direct light to thrive, while others prefer lower levels  of indirect light. 

• Put plants that can tolerate full sunin south- and west-facing windows, plants that like partial shade in east-facing windows, and low-light plants in north-facing windows. 

• Most flowering plants need to be within three feet of a sunny window. 

• Most plants require 12 to 16 hours of light per day. 

• Rotate plants occasionally, to encourage even growth and prevent legginess.

When selecting indoor plants for your home, first consider the characteristics of the location you have in mind for the plant.

Remember to think about the amount  and duration of light over the entire year as well. Often you will see plants classified according to whether they prefer low,  indirect or direct light. 

Low light conditions are those which receive 25 to 100 foot candles of light intensity and never any direct  light. This characterizes the northern window for most of the year and distances of beyond eight feet for  the other directional exposures.  

Indirect light exposures receive 100 to 300 foot candles of light intensity for periods of two but less than  five hours each day. This condition is typical for the east and west-facing windows and at least two feet  away from the window sill of a southern exposure. 

Generally, the west window receives higher light intensity and becomes hotter than an east window. The western exposure would be characterized as having indirect light through the morning and early afternoon.  Later in the day, direct light would penetrate the window exposure from four to six hours depending upon  exterior obstructions and the time of year.  

The eastern exposure is characterized by indirect lighting for the majority of the day and through spring,  fall and winter. In the late spring, summer and early fall, constant direct light would penetrate the window.  The east window is a good site for many flowering plants that do well under cool conditions. 

Southern exposures receive the greatest amount of direct light. Direct light exposures receive between 300  and 1000 foot-candles of light intensity and about five hours of direct sun.

Few plants can survive the light and heat intensity of this exposure with the exception of cacti and succulents. 

You can read my in depth guide that focuses on how to give your house plants the correct amount of light here!

Does my plant need a sweater?

Indoor plant temperature

A second factor often interrelated to light exposure is temperature.

The temperature in your house is usually set for your comfort and not for your plants.

Most houseplants thrive at temperatures between 65°F and 75°F.

Homes are often kept at these temperatures, but some areas are warmer than others.

For example, a sunny window sill in a room on a summer day will have a higher temperature than the interior of that room.

Keep plants away from drafts of hot or cold air, and icy window panes.

During winter, a shade, drape, or newspapers can be placed between plants and the window glass to protect them.

Keep plants away from air conditioners and heat vents.

Plants usually grow best when the night temperature is cooler than the day temperature. 

Danger signs that conditions are too warm are wilting lower leaves  with brown margins, short-lived flowers and spindly growth.

Conversely, keep your plants away from air conditioning vents in the summer.

Sudden temperature fluctuations can cause rapid yellowing, dropping  leaves.

Curling leaves that turn brown and drop also indicate that it is too cold.  

Is it humid enough in here? 

Humidity solutions

Humidity is a tough factor to perfect, as most homes are fairly dry—especially in the winter.  

Here are some things to consider about humidity: 

• Many of the most common indoor  plants come from tropical regions, where humidity is naturally high. They will be happiest when the relative humidity is kept at 50 percent or higher. 

• Plants like cacti and succulents can tolerate  lower levels of humidity. 

• Group indoor plants near each other to form a support group to cope with the low humidity of most winter homes. 

• Occasionally turning on a humidifier near your plants can be effective at combating indoor dryness.

Nearly all houseplants prefer a humidity level of 50% or more.

Houseplants may suffer, especially during  the winter, from a lack of humidity.

A simple method to increase the humidity is to place plants in a pebble  tray.

This is a tray lined with pebbles and filled with enough water to reach to just below the pebble’s  surface.

The water evaporates from the tray up into the air around the plants increasing the relative  humidity. 

How much Water does my plant need? 

Plants are 90% water.

It is very important for them to have the proper amount of water at all times or they can wilt.

Water carries nutrients from the soil to all the different parts of the plant. If the plant does not receive these nutrients, it will starve.

Some plants, like cacti, grow naturally in places where there is little water. They can live without water for long periods of time.

Other plants, such as certain bamboos and bald cypress trees, like to have their roots soaking in water constantly.

Most houseplants come from tropical rainforests where they get plenty of rain and high humidity. They grow best when their roots remain slightly damp all of the time.

Believe it or not, more indoor plants die from overwatering than from anything else!

Knowing  the watering requirements of your plants will go a long way in keeping them happy  and healthy. 

• Starting in late fall, water indoor plants sparingly until daylight hours begin to increase  again in the new year. 

• Water plants with room-temperature water. Cold water can be a shock to a indoor plants roots—like sticking your toes into an ice bath! 

• Use filtered water if your tap water contains high amounts of minerals or chemicals.  Fluoride can cause the leaf tips of some indoor plants, such as peace lilies, to turn brown.

• Add a few drops of ammonia to one quart of water used for indoor plants; it will improve  foliage color and increase growth. 

• Water indoor plants in unglazed clay pots more frequently, as the porous clay will absorb  and evaporate some of the water. 

• Frequent misting’s under the leaves of indoor plants will discourage spider mites.

• If your indoor plants leaves are dripping, even when you haven’t watered, it’s trying to rid  itself of excess water (a process called “guttation”). This makes a plant vulnerable to  disease-causing fungi, so you’ll want to avoid this problem by reducing the amount of water  you’re giving the plant, especially in winter months. Also, watch those drips because they  contain salts, sugars, and other organics that could stain whatever it is they’re dripping on.

Overwatering can cause leaf  spots which are soft and dark brown. It can also cause lower leaves to yellow and drop.

Overwatered plants may look wilted. Both stems and leaves may rot.

Overwatering can also cause houseplants to grow slowly  and flowers to fade quickly and drop. 

On the opposite end of the water spectrum, too little water can cause leaf spots that are brown and brittle or blighted leaf margins.

Lower leaves may  turn completely brown, dry up and drop off. Flower buds may fall off or the plant may produce no flowers  at all.  

You can read my in depth guide that focuses on how to water your house plants the right way here.

Do I need to feed my Plant?

Fertilizer Needs

All houseplants need adequate amounts of food to grow. Look for a balanced plant food with an N-P-K  analysis like 10-10-10.

Feeding should be done only while the plant is actively growing or flowering.

Three feedings during the growing season, starting in April and extending through June, is usually sufficient.

The most commonly used plant foods are dissolved in water.

Some gardeners prefer the encapsulated, slow release fertilizers that may be sprinkled on the soil surface or worked into the soil. 

Over-fertilizing plants can cause brown, crisp leaf margins. Flowers may not develop on overfed plants.

A white mineral crust on the outside of clay pots or on the soil surface is a sure fire sign that the plant is being  over fertilized.  

How do I Give my Plant a Hair Cut?

Pruning Your House Plant  

Removing any shriveled or discolored leaves and cleaning dust from your house plant will not only make it  look more attractive; it also allows the plant to function more effectively.

Leaves can be cleaned with a soft  cloth while supporting the leaf with one hand. Some gardeners use commercial leaf shiners. They should be used with care and in moderation.

Liquid shiners should be applied with a soft cloth and never applied  directly onto the plant. Monthly applications are more than sufficient. 

Some plants can benefit from an actual rain shower. Smaller plants can be washed by placing your hand over the top of the pot to keep the soil from falling out, inverting the plant, immersing it in a solution of  mild soapy water and swirling it around for a few seconds.

This is especially good if you suspect insect  problems. 

Some houseplants can get out of hand and deteriorate if not regularly pruned. Pruning can modify and redirect growth, improve structure, reduce size, as well as remove diseased branches and foliage.

Prune with sharp clean scissors or scissor action pruners. Stems can be removed to open up the plant.

New growth will be generated in the remaining stems or from the plant’s base. Stems pruned above a leaf or a  growth bud will develop one or more new tips making the plant appear denser. 

One simple technique to control growth is by pinching back the growth tip with your thumb and forefinger. 

Pinching is really pruning on a small scale. Pinching back the young growing tip causes the plant to branch  out below the pinch, promoting new growth and a fuller plant.  

When Should I Repot My Plant?

Transplanting and Repotting

The amount of space available for root growth can limit the size of a plant.

When a plant’s roots grow out the bottom of its container, the plant is called “Root-bound” and is ready for repotting.

Changing the size of the container or pot is called transplanting or repotting. Each spring a plant’s roots should be looked at closely.

If a plant is having problems, transplanting should be done more often.

If the roots are dense and wound around the bottom of the soil ball, and the soil dries out quickly even with frequent watering and roots may begin to grow out of the drainage hole, the plant is ready for a larger container. 

This prevents the plant from becoming root-bound. Root-bound plants have very slow  leaf and stem growth.

The pot should be the proper size for the plant. The diameter at the top of the pot should be equal to 1/3 to 1/2 the height of the plant.

If the pot is too large, it will hold too much water in the soil and damage the roots. If too small, the growth of the plant may be stunted. 

Plant Size  

Small plants transplant more easily  than larger ones; however, any plant that  already is established in a container can be repotted.

When first planting into pots, select small plants so you do not have to  remove many roots to fit the plant into the container.

Pot rooted cuttings when the roots are about 1⁄2 inch long. Seedling plants transplant most readily as soon as the first true leaves have formed. 

Plant Condition 

Most plants transplant best when they  are actively growing.

Dormant plants or those in flower may not produce root  growth and establish themselves in the new  pot as readily.

Plants should not be wilted when transplanted.

Be sure your plants are well watered and free of insects before repotting.  

Container Type 

Plants can be grown in almost any  container, but it is best to use containers  with drainage holes.

To establish plants in  decorative containers without drainage  holes, leave the the plants in nursery pots that fit inside the other containers.

You can com bine several small pots in a larger planter by  packing sphagnum moss around the sides of  the pots for support and to help evaporate excess water.

Clay pots are no better than plastic ones, but porous and nonporous pots require different management.

For one thing, soil in clay pots dries more rapidly and requires more frequent watering than  that in plastic pots. 

Container Size

Normally it is best to keep a plant in the  smallest container needed for its current  stage of development.

This practice con serves growing space, reduces the likelihood of overwatering, allows for gradual  increases in pot size (and new soil) as the  plant develops, generally looks better (small  plants in large pots look lost), and allows  more versatility in moving plants or arranging them in groups.  

Adjust container size to manage irrigation schedules.

Move plants that need more frequent watering to larger pots with more  water storage capacity. 

Potting Soil Mixtures  

Plants growing in containers require  specially prepared soils or growth media. 

A container-grown plant cannot extend its  root system to gather water and nutrients,  but is limited to the small volume of soil in  the container.

Potted plants use the soil in  their pots much more intensively than they  would if growing unrestrained outdoors. 

Even the most fertile garden soil will not  sustain this intensive use for more than a short time. 

Ready-to-use potting soil mixes are avail able in garden stores. Some of these commercially prepared potting soils are excellent but expensive.

If you have only a few houseplants, prepared mixes are convenient  and probably the most practical.

However,  if you grow numerous houseplants, it may  be more economical to prepare your own  potting soil. 

Good potting soil differs from garden  soil. It should contain a much higher  proportion of coarse mineral particles to  maintain sufficient pore spaces in the soil  for air, water, and root growth.

It must have  enough organic matter to hold water and  condition the soil (keep it from compacting).

It also must contain sufficient mineral  nutrients to supply a large part of the plants’  needs. (All houseplants need supplemental  fertilizer on a regular basis.)

Good potting soils can be prepared by  mixing garden soil, coarse sand, pumice or  perlite, and peat moss.

Most potted plants  grow quite well in a mix containing equal  parts of these ingredients if you adjust management techniques (watering and fertilizing) to suit their different needs.

House Plant Problems

Diseases from who knows where…

Spots, rots, wilts and mildews on your houseplant are symptoms of disease. It is important to identify the  problem correctly so it can be treated effectively.

Black shriveled sections of stem just above the soil line  may indicate a disease called blackleg caused by a fungus.

Soft, slimy stems with black or brown decayed areas can be symptoms of crown rot, also caused by a fungus.

Brown leaf spots which grow and merge can  be either bacterial or fungal leaf spot diseases.

If any of these symptoms occur, a recommended treatment  includes destroying infected leaves, using a fungicide and modifying cultural practices.  

Yucky Pests

There are a variety of pests which plague houseplants. Identify the pest and apply the appropriate remedy  as soon as the first symptoms appear. Repeated treatments may be required to break the life cycle of  overlapping generations of most of these insects.

Aphids

Aphids are small sap-sucking insects, usually green, black or orange found on new, succulent growth. They  cause discoloration and distortion of the leaves and secrete sap called honeydew which can encourage  black fungal growth on leaves. 

Remove aphids from indoor plants with a mixture of equal parts rubbing alcohol and water  and add a drop of dishwashing detergent. Apply this to troubled plants with a soft brush.

Mealybugs

Mealybugs and scale are commonly seen on indoor plants. Mealybugs appear as small white cottony tufts in clusters on the stems and underside of leaves. Mealybugs cause wilting, yellowing and leaf drop. 

Scale looks like small, brown discs commonly attached to the underside of leaves along the veins and on the  stems where they suck sap.

Plant vigor will decrease, leaves will yellow and black fungal growth may  develop on honeydew secretions.  The mixture of rubbing alcohol,  water, and dishwashing detergent outlined above works on mealybugs and scale, too.  Regular monitoring of your indoor plants is key to beating an infestation. 

Infested leaves develop  yellow mottling and blotching and drop prematurely. You may find fine webbing on the leaves. 

Spider mites

Spider mites, which are also sap-sucking pests, proliferate in hot, dry conditions.

Spider mites are apt to thrive in warm, dry houses. Frequent misting under the leaves of  indoor plants will discourage them. A solution of 1 cup flour, ¼ cup buttermilk, and a  gallon of cool water, applied in a mist, is a good organic deterrent. 

Fungus Gnats

Small flies may occasionally appear around indoor plants. These are called fungus gnats and are harmless to plants (and humans) in their adult form, though their larvae can damage young roots.

Letting the soil dry out a bit between watering’s can discourage  fungus gnats from calling your indoor plants home. 

Whitefly

Whitefly is a small, white, moth-like insect that can spread rapidly. Greenish larvae suck sap on the  underside of the leaves which then turn yellow and drop.

When the plant is disturbed, the winged insect  can be seen flying out of the foliage. 

Read an in-depth guide to houseplant pests here.

Cacti and Succulents as Houseplants 

A group of plants called succulents that have either fleshy stems and/or leaves are often chosen as houseplants for direct light conditions.

Their ability to endure drought is reflected in the succulent  leaf/stem condition where water is stored.

These plants come from many plant families; most notably the cactus family.

Others in this group come from sub-tropical areas where light conditions are less extreme  and moisture is more abundant.

This group is referred to as the jungle cacti and includes the Christmas,  Thanksgiving and Orchid cacti. 

Cacti and succulents generally require at least 4 hours of bright, direct light each day. However, some  including the jungle cacti, prefer medium light and should only receive direct light in winter.  

Most cacti and succulents tolerate the low humidity and warmth of the home. Jungle cacti require higher  humidity and should be placed on a tray of moistened pebbles or rocks.

Some cacti will do better if  presented with a rest period during the winter.

Provide these plants with cool conditions and as bright  light as possible. Window sill and cool basements are good sites for these plants. 

The most frequent cause of problems with cacti is due to overwatering. To water cacti, check the moisture  level by sticking the index finger into the soil.

Generally, cacti will need watering every 2 to 3 weeks during  the growing season and once a month in during the winter.

It is best to allow the soil to dry out between waterings. 

Jungle cacti should be kept evenly moist all year around, especially during the flowering period of late fall  or early spring.

When flowering has stopped, water should be withheld to allow the top of the soil to dry  out before waterings.

Popular Indoor Plant Care Guides

Aglaonema (Chinese Evergreen)

Average warmth, indirect to moderate light, can tolerate low  light. Keep away from direct sun. Water thoroughly spring through autumn, sparingly in winter.  Prefers moist air, avoid extremely dry locations. Repot in spring every 3 years.

Aphelandra (Zebra Plant)

Average warmth, bright indirect light away from direct summer sun.  Keep compost moist at all times but never water logged. Reduce watering in winter. Repot in spring  every year. 

Bromeliads (Air Plants)

Average warmth, indirect light away from direct sun. Keep central vase filled with  water, for non-vase varieties keep compost moist, but never wet. High temperatures (above 75 F)  may be needed to bring plants into flower. Repotting rarely, if ever, needed. 

You can read our ultimate guide to air plants here!

Chlorophytum (Spider Plant)

Average warmth, indirect light away from direct sun. Water liberally  spring to autumn and sparingly in winter. Florine in water will cause leaf tips to turn brown. Repot if  necessary in spring. 

Dieffenbachia

Average or above average warmth, indirect light in summer, moderate light in  winter. Water regularly spring to autumn and sparingly in winter. Repot in spring. 

Dracaena

Average warmth, moderate light close to east or west window. Keep compost moist at all  times and reduce watering in winter but do not let it dry out. Repot in spring every two years. 

Ferns

Average warmth, Indirect light, east or north facing windowsill ideal. Compost must be kept  moist, but not soggy, at all times and never allowed to dry out. Reduce watering in winter. Repot in  spring when roots fill the pot. 

Ficus (Figs, Rubber Plant)

Average warmth, Indirect light for tree types, moderate for others.  Allow tree types to dry out between waterings, trailing types need more frequent watering. Apply  little water during winter. Repot in spring, but avoid frequent repotting. 

Hedera (Ivy)

Does best in cool temps, but above freezing. Indirect light, avoid direct sun in  summer. Keep compost moist in summer through regular watering, water sparingly in winter but  never let compost dry out. Repot in spring as needed. 

Hoya (Wax plant)

Average warmth, keep cool in winter. Bright indirect to moderate light avoid  direct summer sun on variegated plants. Water liberally spring to autumn, sparingly in winter. Do  not remove fleshy flower buds. Repot only if unavoidable. 

Kalanchoe

Average warmth, bright direct sun (east or west windowsill spring – autumn, south in  winter). Water thoroughly, let surface dry between waterings. Can be induced to re-flower with a rest  period. Repot in spring after rest. 

Maranta (Prayer Plant)

Average warmth, sensitive to low humidity environments. Moderate light,  colors fade in bright light. Keep compost moist at all times but reduce watering in winter. Repot in spring. 

Monstera Delicious (Swiss Cheese Plant)

Prefers full sun, but can be adapted to part shade. Medium. Grows best in warm temperatures with high humidity

You can read our ultimate guide to growing massive monstera delicious here!

Palms

Average warmth, most do best in Moderate light, protect from direct sun. Requires good  drainage, Keep soil moist, but do not over water. Reduce watering in winter but keep soil slightly  moist. Repot only when roots thoroughly pot bound. 

Peperomia

Average warmth, indirect or moderate light away for direct sun. Will thrive in fluorescent light. Allow compost to dry out between watering, but never wait until the leaves wilt.  Water sparingly in winter. Repot only if necessary. 

Philodendron

Average warmth, moderate to low light, will suffer in direct sun. Water thoroughly  and regularly spring through fall, keep soil moist in winter. Repot in spring every couple years. 

Saintpaulia (African Violet)

Average warmth avoid cold drafts and sudden temperature changes.  Bright indirect light, ideally an east or south facing window in winter and a west window in summer,  but protected from strong sunlight. Keep compost moist and bottom or top water when surface of  compost is dry, or use a wicking double pot. Avoid getting leaves wet. Remove dead flowers and  leaves, repot in spring if necessary. 

Sansevieria (Snake Plant)

Average warmth, bright indirect light with some sun preferred but will  grow in low light as well. Water moderately spring to autumn allowing compost to dry out slightly  between waterings. In winter water only every 1 – 2 months. Repotting is seldom required and  should be done only when growth cracks the pot. 

Schefflera & Heptapleurum (Umbrella Plant)

Average warmth, bright indirect light, avoid direct  sun. Water liberally spring to autumn and sparingly in winter. Repot in spring every couple years if  necessary. 

Scindapsus (Pothos)

Average warmth, moderate to low light. Water liberally spring to autumn  allowing soil to dry out slightly between waterings. Water sparingly in winter. Repot if necessary in  spring. 

Spathiphyllum (Peace Lily)

Average warmth, keep out of cold drafts in winter. Will grow in low  light, but will flower best in indirect light. Keep out of direct sun. Keep compost moist at all times,  reduce watering in winter. Repot in spring as needed. 

Succulents (Aloe, Jade, Sedum)

Average warmth spring to summer. Prefers to keep cool (50 – 55F)  in winter. Windowsill is ideal location to provide bright indirect light with some direct sun. Water  thoroughly when compost begins to dry out spring through autumn, in winter only every 1-2 months.  Repot in spring, only when essential. 

Syngonium or Nephitis (Arrowhead)

Average warmth, indirect (variegated varieties) to moderate  (all green leaves) light. Avoid direct sun. Keep compost moist at all times, reduce watering in  winter. Avoid over watering. Repot in spring every 2 years. 

Tradescantia (Wandering Jew)

Average warmth, bright indirect light essential and some species  benefit from some direct sun. Water liberally spring to autumn, sparingly in winter. Repot if  necessary in spring. 

Zamioculacas (Zee-Zee)

Average to warm room temperature, moderate light. Allow upper part of  compost to dry out between waterings. Water sparingly in winter. Repot in spring.

Good Indoor Plants for Indirect Light Conditions