Houseplants are a diverse group; the term is used to describe everything from a cactus to an orchid. This diversity can make plant care challenging (and occasionally frustrating). There are some pretty simple and common things to remember when selecting and caring for houseplants.
If you haven’t purchased a plant yet, choose a healthy plant to begin with:
- Look for a plant that’s bushy, with buds or new growth. Avoid plants that are “leggy,” (a term used to describe plants that are too tall and thin).
- Avoid plants with brown edges on the leaves – which could mean the plant has been subjected to too much heat or fertilizer.
- Beware of pale or yellow lower leaves, a sign of improper watering.
- When you get home, do not be surprised if some lower leaves drop off. The plant may simply be adjusting to its new environment.
Proper Light for Houseplants
Without light a plant will starve, unable to produce food, or photosynthesize. (Plant photosynthesis is also the process that removes carbon dioxide from the atmosphere, replacing it with oxygen). So, the placement of your plants in the home is critical. A home will contain many microclimates; for example kitchens and baths normally are more humid. Plants do not have to reside on a windowsill, but if yours do, here are some enlightening facts.
Remember that windows facing:
- North – receive no direct sun, but supply good light for foliage plants. Providing extra light in winter might be in order.
- South – are the brightest and may be too bright in summer.
- East – get the “cooler” morning sun, which is excellent for growing.
- West – receive a lot of sun, also excellent for growing. However, plants may need some relief from intense sunlight.
More Light Facts
- Plants are phototrophic – they grow towards the light source. Turn your plants regularly to maintain even growth, at least every time you water.
- Variegated (foliage plants with leaves of more than one color or shade) plants require more light than purely green ones.
- Most plants do their growing at night, so make sure to provide a daily period of darkness.
- Light colored walls reflect more light than dark walls. Plants will feel the effects of this indirect light – something to keep in mind when placing plants.
- Flowering plants will generally need more light than foliage plants. In fact, the more light they receive, the more flowers they will produce. (But don’t forget a nightly rest in the dark).
- You may want to consider providing additional artificial light in areas where sunlight is scarce during winter months.
Temperature and Air
As stated above, most plants do their growing at night. Just as plants need light to produce food, they also need a daily period of cool and dark to prosper. Temperature needs vary by plant, but on average, houseplants enjoy temperatures ranging from 65° to 80° F during the day and 55° to 65° F at night. Today, most homeowners tend to maintain a constant temperature, averaging around 70° F. Most plants will adapt to this temperature, but some flowering plants cannot set new flowers without cool evenings.
As always, read the plant label for its specific requirements.
- Do not let leaves touch windowpanes, especially if your winters are cold.
- Plants need circulation, but do not respond well to drafts.
- Pollution from smoke, gas, kerosene, even ripe apples (which create ethylene gas) can affect plants.
Overwatering is the most common cause of plant death. Roots need air as well as water. Soil that is too wet will begin to smell, the roots will rot, and diseases will find a home in the wet environment.
When to Water
Some plants need constant moisture; some prefer a much drier environment. The good old standby test is to stick your finger into the soil to a depth of 1 – 1 1/2 inches midway between the rim of the pot and the base of the plant. If the soil feels dry, then it’s time to water. In most cases, watering should be done in the morning. As you’ve probably heard, plants don’t like to go to bed with wet feet.
How to Water
Water must reach all of the root system to be beneficial, so when you water, do it generously rather than a little every day. Always read the plant tag for specific instructions. Water around the base of the plant, not over the flowers or foliage. Use room temperature or tepid (around 90° F) water. When water begins to flow from the drainage hole – stop. Pour off the excess water from the saucer. If the water comes out of the drain hole immediately, the plant may be completely dried out.
Another sign of an overly dry plant is when the soil is pulled away from the outside edge of the container. An extremely dry plant can be immersed in a sink or other container of water for about 30 minutes. The moisture will be drawn up through the drainage hole.
Wicks and self-watering systems are options you may want to consider. Wicks are inserted through the drainage hole. The pot sits slightly elevated in a saucer or other container (not directly in the water). The other end of the wick is placed in the saucer, which contains water. The wick ensures that the soil will remain consistently moist (as long as the water level is maintained in the saucer).
Homes are generally dry. Additional moisture can be provided by grouping plants or placing in a tray on a layer of damp pebbles. Smooth-leaved plants can be misted or washed. Do not spray or wash a hairy-leaved plant (such as an African violet).
Using the Right Soil
The growing medium is an important aspect of plant care. Your best bet is to buy prepackaged soils. Soil from your garden could contain fungi, bacteria, insect eggs, weed seeds or undesirable elements that you wouldn’t want to bring into your house.
The most common types of bagged soil include:
Potting mix – the best choice for potting or repotting. Potting mix should contain organic matter, as well as elements for aeration and moisture retention (perlite and vermiculite). Charcoal may also be an ingredient.
Professional grower’s mix – also known as greenhouse mix. Because of its fine texture, it is very good for starting seeds. But for the same reason, it will also dry out very quickly.
Planting mix – contains compost and sand and is recommended for outdoor use, not houseplants.
Topsoil – is basically compost. Because of the rough texture, it’s best to use in the yard, not as a potting soil.
Flowering plant mix – contains more acid to promote flowers, otherwise similar to potting mix.
Cactus mix – absorbs water easily, and then dries quickly. Use with cacti and succulents.
A houseplant’s root system is limited by the boundaries of its container and cannot go in search of food as an outdoor plant will. For that reason, feeding is necessary for a healthy plant. Nitrogen, phosphorus, and potassium are the three main nutrients contained in most plant foods.
Fertilize houseplants during their growing (not dormant) season. Too much fertilizer can damage a plant. Specific needs will depend on several factors – the plant itself, the amount of light it requires, whether it is a flowering or foliage plant. In general, plants that require more light will require more frequent feeding. Above all – read the label on the plant food.
- Do not apply heavily if the soil is dry, the fertilizer could burn the roots.
- Do not feed if the plant is dormant. Wait until they are actively growing.
- Do not exceed the recommended dosage.
Repotting a Plant
The container of the plant affects how often you should water it. Clay dries out more quickly than plastic since the material is porous which helps prevent the soil from getting too saturated. Because of this same characteristic, plants in clay pots may need watering more frequently. Clay pots can be waterproofed if you wish.
Other waterproof containers, such as plastic and ceramic, will definitely hold water, so look for a container with a drainage hole. Drainage holes allow excess water and harmful salts to escape. Remember any pot with a drainage hole in the bottom needs a saucer underneath.
Within a plants’ lifetime it may become necessary to move it to a bigger container. A few plants need to be slightly rootbound in order to prosper but most plant need additional space as they mature. Repotting is essential to allow root growth.
When the time comes to repot, you may see some of the following signals:
- New leaves are developing smaller than established leaves.
- The plant wilts between normal watering, or the leaves turn yellow.
- Roots are visible on the soil surface or coming from the drainage holes.