Indoor Tropical Plant Care
- Caring for your tropical plants upon arrival
- Cultural information
- Lighting for tropical plants
- Temperature
- Humidity
- Watering
- Fertilizing
- Soil
- Ventilation
- Containers
- Pest Control
- Fluorescent Lighting
Caring For Your Tropical Plants Upon Arrival
Open the box as soon as it arrives and examine the plants. Remove any leaves that may have become damaged during shipment. The plants will probably still be moist, but water any that feel dry. Do not fertilize them. Keep the plants out of any direct sun or strong light. Within a few days, you can gradually introduce them to the light level they need and to the location chosen for them. To help the plants adjust to your new environment, we suggest the following:
Place the tropical plants in one or more large, clear plastic bags. The bags will allow extra humidity to build up around the plants and help them recover from the shock of traveling. Leave the top of the bag partially open, and place the bags in a low to medium light area. Gradually, over the next seven days, roll the bag down from the top, exposing a little more of the plant each time. This way, the plant slowly becomes accustomed to its new environment.
Do not repot the plant until at least two weeks after its arrival. Again, this will allow the plant time to adjust before disturbing its roots. When potting up, only go up one pot size at a time (i.e. 2 ½ inch or 3 inch pot - go up to a 4 inch pot). Start a regular fertilizing program one month after repotting.
Cultural Information
In order for you to be successful with your indoor tropical plants, there are a few basic cultural and environmental requirements that must be met. Each plant has its own idiosyncrasies and its own particular needs, but a knowledge of the basic requirements will help you provide what is needed. If you are introducing a new plant to your environment, you may have to try it in several locations until you find the one it likes the best.
Light: Most tropical plants in our catalogue will enjoy medium to bright light, but not direct sun, except in the winter. If a plant requires some sun to trigger flowering, this will be noted in the individual plant descriptions. Plants with variegated foliage do not photosynthesize quite as well as the all-green varieties. Therefore, variegated plants require more light than do the all-green varieties. If your home is exceptionally dark, consider growing under fluorescent lights. Plants do not enjoy sudden changes between high and low light conditions. Introduce them gradually to a new light situation.
Temperature: There are tropical plants that prefer cool temperatures and others that like it warm. The ideal temperature range for most plants is between 55°F and 75°F (13°C to 24°C). Plants are like people - they don't like it too cold or too hot! Plants can tolerate higher temperatures if they are provided with extra humidity. Most plants like a 5 to 10°C drop in temperature from day to night, but do not enjoy sudden temperature changes. Drafts from open doors or windows in the winter should be avoided. When placing plants in a room, be aware of factors that influence temperature in different parts of the room such as sunny south or west-facing windows, hot radiators or heating vents in the winter, and air conditioners in the summer.
Humidity: Most of the tropical plants in our catalogue will grow under normal room conditions if you can provide at least 30% humidity. This is especially important in the winter when central heating tends to dry out the air. Extra humidity can be added by misting daily, by the use of pebble trays, or by using a room humidifier. Some plants need extra humidity to thrive and any special humidity requirements such as this will be noted in the individual plant descriptions. We grow most of our high humidity plants in terrariums.
Watering: Most tropical plants die from incorrect watering practices and overwatering is usually more of a problem than underwatering. For most plants, good watering technique involves letting the soil dry out slightly between waterings and then watering thoroughly. Plants should never be allowed to dry out severely to the point of wilting. On the other hand, if your plant pot is sitting in a tray, do not let the pot sit in water for more than 30 minutes. If there is still water in the tray after half an hour, pour it out. Plants like to be moist, but not soggy. To see if our plants are ready to be watered, we check them in two ways. We lift the pots. If the pot feels heavy, it is a sign the soil is still wet. (If you're using a clay pot, take into account the fact that clay itself is heavy.) If the pot feels light, the soil is dry. We also check moisture content by sticking a finger about 1 inch into the soil. If the soil feels dry, then it is time to water. If in doubt, it is better to wait a day to water. Most of the plants in our catalogue like to go through a moist / dry cycle. If a plant prefers to be constantly moist, we will note this in the plant description.
Other factors to consider when watering include: the size of the plant; the size of the pot; the time of the year (summer versus winter, which affects the plant’s rate of growth), the temperature of the room, the humidity of the room, and the type of plant. Most plants with thick leaves are succulent in nature and store water, while plants with thin leaves may lose water rapidly. Always use room temperature or tepid water. If your water supply is highly chlorinated, let your water sit uncovered overnight to allow the chlorine to evaporate. If your water supply is hard, you may need to filter out some of the mineral content. However, never use water that has been softened with a water softener.
It is important to water your plants when THEY need it, not because it's Thursday! Don't water on a schedule. Plants don't know what day of the week it is! With any collection of plants, some will need watering on any given day and some will not. As you get to know your plants’ growth habits, you'll be able to water when they need it. Watering is not difficult, it just requires an awareness that plants are living organisms with their own individual needs.
Fertilizing: Because indoor tropical plants are growing in a confined space, they do need regular applications of fertilizer to promote healthy growth. However, be careful not to over-fertilize your plants. Most plants like frequent feedings of a dilute fertilizer, rather than concentrated and infrequent applications. Dilute your fertilizer to ¼ the strength recommended on the package and feed with every watering, which is usually once a week in the summer. Under fluorescent lights, where you might water twice a week, fertilize with every second watering. In the winter, for plants grown with natural lights, stop fertilizing until you see new growth in the spring. It is also a good idea to give your plants a rest from fertilizing and hold off on the fertilizing for one week each month.
When choosing your fertilizer, look for one that contains not only the three main nutrients of nitrogen (N), phosphorus (P), and potassium (K), but also some of the trace elements such as calcium, magnesium, iron, copper, and boron. We prefer to use liquid or soluble fertilizers so that the nutrients become available to plant almost immediately. It is also a good idea to change your fertilizers occasionally to ensure that your plants get all the various nutrients that they require. Best plant growth will be obtained with fertilizers that contain equal or almost equal amounts of nitrogen, phosphorus, and potassium.
Soil: Commercially packaged potting soil is usually too heavy to be used as is. Most plants, and especially begonias and gesneriads, grow best in a light porous soil. We suggest the following soil mixes:
For Tropicals:
4 Litres of commercially packaged potting soil
1 Litre of coarse vermiculite
1 Litre of perlite
1 Tablespoon of steamed bone mealFor Streptocarpus and Begonias:
4 Litres of commercially packaged potting soil
2 Litres of coarse vermiculite
2 Litres of perlite
1 Tablespoon of steamed bone meal
For other Gesneriad's:
If you only have a few gesneriads, use a commercial African Violet soil with a little extra vermiculite and perlite added. If you are a serious grower, we have a special gesneriad soil recipe which we can e-mail to you upon request.
Ventilation: Ventilation and air circulation are important for healthy tropical plants and are a part of houseplant culture not often mentioned. Plants need fresh air and will not do well in stuffy, overheated rooms. Ventilation can be provided by opening windows, except in the winter when the outdoor temperature is very cold. Indoor air can be circulated with table or ceiling fans. Ceiling fans are the most effective. If the room temperature becomes too hot in the summer you can use an air conditioner, but don't place plants directly in front of the cold air. In the spring, summer and fall try to give your plants as much fresh air as possible. In winter use a ceiling fan set on low to keep the air moving.
Containers: There are a wide variety of containers and pots available for the growth of indoor tropical plants. For many years clay pots were the pot of choice but they can be expensive and are prone to chipping and breaking. We prefer plastic pots because of price, washability, and general ease of use. Whatever type of pot you use, make sure that the pot has drainage holes in the bottom. For a healthy root system, the water must be able to pass quickly through the potting soil. If you like the look of decorative glazed pots, we have always found it better to grow the plant in a plastic pot, which is then placed inside the decorative pot. This makes it much easier to correctly water the plant or to remove it for repotting.
The size and shape of the pot is also important. Many people make the mistake of overpotting their plants and placing them in pots that are too large for their root system. In such cases the soil stays too wet and the roots will eventually rot. Indoor plants generally do better if they are slightly underpotted. In fact, some plants like to be slightly potbound to encourage new growth or flowering.
There are two basic shapes of pots - the standard pot and the Azalea pot. With standard pots, the depth and the width across the top are almost the same. With Azalea pots, the depth of the pot is about three quarters of its width. Azalea pots are used for plants that have shallow root systems, such as many gesneriads, African Violets and ferns. The following plants in our catalogue need Azalea pots and will not do well if planted in pots that are too deep:
- African Violet
- Primulina, Streptocarpus
- Davallia
- Rhizomatous Begonia
- Nematanthus
- Codananthe
Pest Control: If you have many houseplants, you will inevitably have to deal with insect pests such as spider mites, fungus gnats, thrips, mealy bug and scale. For some begonias, powdery mildew is a common fungal disease. Successfully dealing with these pest and disease outbreaks means you must treat the problem immediately. Make a habit of checking your plants regularly when you water them for any signs of insect problems or mildew. It is easy to remove one or two mealy bugs when first detected, but an infestation can quickly kill a plant and spread to others. We suggest using biological controls or insecticidal soap whenever possible. We use insecticidal soap and a product called Neem Oil, which controls both insect pests and powdery mildew.
If you do develop problems, you must be persistent in treating the affected plant(s). It will usually require three or four treatments, spaced one week apart, to eliminate the problem. If you find a particular plant is especially susceptible to mealy bug, aphids, or spider mites, then monthly preventative spraying will usually keep the situation from getting out of control.
If you grow a lot of begonias, we suggest spraying monthly with Neem Oil as a preventative treatment for powdery mildew. Our mixture consists of 2 ml of Neem Oil in 250 ml of warm water, plus two to three drops of dish soap to help the oil disperse. Shake the mixture frequently during use. Spray all surfaces of the plant and the surface of the soil. This solution is also excellent for spraying other flowering plants such as African Violets and Streptocarpus as it does not damage the flowers.
For mealy bugs, a Q-tip dipped in alcohol and applied to the affected area works well. Follow this with a thorough Neem Oil spray. Neem Oil is the most effective treatment we have found for scale and mealy bug.
Fungus gnats can be another problem. Fungus gnats are tiny black flying insects that can be seen hovering just over the surface of the potting soil. If fungus gnats are present in large numbers they are a nuisance aesthetically and their larvae in the soil may feed on the plant roots. The use of yellow sticky traps will capture the flying adults. However, to kill the larvae in the soil, it is necessary to water in a pathogenic nematode called Steinernema feltiae. The nematodes eat any fungus gnat larvae which are in the soil. If you have a large plant collection, you will eventually get fungus gnats. The nematode treatment should be done twice a year; once in the spring and once in the fall. Nematode shipping is time-sensitive. You should always try to order them on a Monday so that the nematodes are not delayed in shipping over a weekend. When applying the nematode treatment, be sure to read the instructions carefully. In order to remain viable, the nematodes need to be kept in your refrigerator at 5°C (note the expiry date) until you are ready to use them.
For spider mites and aphids we find insecticidal soap to be very effective. Again, you must spray the affected plant three or four times, at one-week intervals, to eliminate the problem.
Back to top
Growing Tropical Plants Under Fluorescent Lights: Growing under fluorescent lights allows you to increase your growing space if your home does not have a lot of natural light. Growing under artificial lights is especially good for condominium or apartment dwellers who have a limited number of windows. It also allows flowering plants to be kept in flower throughout the dark winter days. Under lights, plants such as Streptocarpus and Primulinas will not go through a prolonged dormant phase, but will continue to grow and bloom as if it were summer.
Growing under fluorescent lights involves using two or four, 48-inch, 40-watt fluorescent tubes placed in a reflector unit. A good wide reflector is necessary so that the light is directed down onto the plants. Do not use the inexpensive ‘shop lights’ sold in most hardware stores. A two tube set-up is good for foliage plants and those requiring low to medium light. A four-tube garden can be set up for plants requiring higher light conditions. Plants growing under lights will need to be watered more frequently because they are exposed to constant light and increased heat from the fluorescent tubes.
Plants requiring more light (i.e. flowering plants) should be placed under the center of the lights and closer to the fluorescent tubes. You can elevate plants by using upturned empty plant pots, or you can build small wooden stands. Plants requiring lower light conditions can be placed further away from the fluorescent tubes and towards the ends of the reflector unit. Any plant that doesn't grow too tall can be grown under fluorescent lights.
We have had good success using one cool white fluorescent tube and one warm white fluorescent tube, or two full spectrum tubes or a combination of cool white and full spectrum tubes. The lights should be left on 14 to 16 hours per day.