Gardening Tip of the Month

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Caring For Houseplants

Watering
There are a variety of factors that affect a plant’s water use and the moisture within the soil including the type and size of the plant, temperature, humidity, light, pot size, potting soil mix, and drainage.  Always allow the soil to completely dry out before watering.  The best way to determine whether or not a plant needs to be watered is to place your finger 1-2 inches deep into the soil.  If the soil is dry, then it should be watered, and if it is moist then it does not need to be watered.  You can also tell if the soil is dry by color.  The lighter the color, the dryer the soil is.  Additionally, the weight of the pot helps to determine if they plant needs to be watered.  A plant that has just been watered will be a lot heavier than a plant that needs to be watered.  Do not use a watering schedule.  Since there are many variables that cause soil to dry out, watering too much or too little can become an issue if a schedule is set. 

Watering can be done two different ways: from the top or from the bottom.  If you choose to water a plant from the top, use a small watering can with a slender spout to keep as much water off foliage as possible.  A sub-irrigation method can also be used.  Place the plant in an inch or two of water either in the sink or its saucer and the plant will soak up the water it needs.  After an hour, dump out the water that remains.  Whether a plant is watered from the top or the bottom, never allow it to sit in water contained in the saucer.

Lighting
Only a few houseplants can tolerate low lighting.  Most plants need to be close to a window to survive.  They will not be able to live away from windows with only interior lighting fixtures as the source of light.  Flowering plants need more light than foliage plants.  Flowering plants need moderately bright light from windows facing south, east, or west.  African Violets and related plants prefer north windows, but the average flowering houseplant needs more light.  Most foliage houseplants that do not bloom can tolerate light from any windows and do not require direct sunlight.  They will even tolerate light diffused from a sheer curtain. 

Temperature
The average temperature for houseplants needs to be at 65-75 degrees Fahrenheit during the day and 55-60 degrees at night.  Usually if a plant is placed on a windowsill or close to a window, the heat during the day and coolness at night will be sufficient.  Be careful in the winter time to make sure that it is not too chilled next to the window.  Some foliage plants can be injured if the temperature in the air around the plant drops below 40 degrees.  It is also best to occasionally mist the leaves of plants in the winter since the air is less humid.

During the summer, houseplants can be put outside.  Just make sure that the plants are not put out too early and are damaged by a late frost.  Typically late May is late enough in spring for plants to tolerate the temperatures.  Note: potted plants dry out very quickly outside compared to plants that are located indoors, so do not forget to water!

Fertilizing
Plants that have just arrived home from the greenhouse do not need to be fertilized for awhile since most likely they were fertilized frequently before purchased.  If plants are going to be discarded after blooming, such as poinsettias, then they will not benefit from fertilizer.  For those houseplants that you are hoping to keep around, fertilizing them once a month is usually adequate, especially when there is a lot of new growth.  In midwinter, December and January, when new growth slows for some plants, fertilizer does not need to be applied.

Repotting
Plants recently purchased will not need to be repotted for awhile.  A good indication that the plant is becoming pot bound is an increase in watering or if it does not appear to be growing at the same rate it used to.  To check the roots, place your hand on the soil and tip the pot upside down to slide off the pot.  If the roots are starting to wrap around the soil, then it is time for a new, larger pot.

Durable Houseplants
Although most houseplants will thrive with little trouble, there are some plants that will take more abuse than others.  Some of the most durable houseplants are:
-Snake Plant (Sansevieria)
-Heart-Leaf Philodendron (Philodendron cordatum)
-Devil’s Ivy (Pothos)
-Corn Plant (Dracaena massangeana)
-Peperomia (Peperomia obtusifolia)
-Cast Iron Plant (Aspidistra)
-Dwarfpalm (Collinea)
-Chinese Evergreen (Aglaonema)
-Spider Plant (Chlorophytum)

For more information on durable houseplants or how to care for houseplants, stop by the greenhouse at Delhi Flower and Garden Center and chat with our knowledgeable growers!  We have a wide variety of tropical houseplants, pots, soil, fertilizer, and all accessories for your houseplant’s needs!

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