- Lack of humidity is one of the biggest problems for houseplants, particularly during winter when heating systems dry air to desert conditions. To raise the humidity, set them on trays or pans filled with gravel and water. Keep the water level below the top pieces of gravel.
- Most flowering varieties require more light than foliage plants. Watch leaves for signs of improper light conditions. If they start turning yellow, move to a spot where it will get less light. And, if your flowering types have deep green leaves and few blossoms, give them more light.
- South and west windows give the most sun during the winter; east windows are best for the summer months.
- Give pots a quarter turn each time you water so the plants won’t lean toward the light and get lopsided.
- Does it have gnats? Here’s a trick to find out if you’re not sure: slice a chunk of raw potato and leave it on top of the soil where you suspect they are thriving (lay it cut side down). After seven days, lift the potato up–if you have them you will see larvae on the potato. From How To Get Rid Of Gnats .
- Save onion scraps to make your own homemade pesticide, see this page .
- If they grow in inadequate light, they should be fertilized sparingly; provide proper light, then feed, and they will become healthy again.
- Submerge newly potted plants in a sink or pail of water to just above the rim of the pot. Leave until bubbles stop rising from the soil; then take out and let drain.
- Always use lukewarm water when watering to avoid chilling the roots.
- When repotting, remove as much old soil as possible from roots, particularly from the top of soil ball, disturbing roots as little as possible. Use a pot proportionate in size to the plant. Shift to bigger pots as they grow larger (see this page ) for more tips.
- Found this tip in an old magazine for homemakers: When going away for a few days, soak a large sponge in water and place it at the base of houseplants, they will stay moist for days. I would use a fresh sponge and not one used at all for cleaning.
- To revive “sick” ferns, water them with 1/2 teacup of salt added to six pints of lukewarm water. If infested with worms, stick matches into the soil, sulfur end down. For an ordinary sized plant, use four matches–six for a large pot. The sulfur does the trick. From this page of Old-Time Tips .
- Unglazed clay pots provide ideal growing conditions. They are porous, providing necessary air circulation to roots, and have drainage holes in the bottom, making overwatering less likely. Plastic pots are lightweight and easy to handle but, as in metal or ceramic containers, water evaporates slowly, so you have to be careful not to overwater.
Source: Better Homes & Gardens House Plants Vintage Insert (unless otherwise noted)
Using Tap Water
Did you know using water straight from the tap is fine to use for most plants but there are benefits to letting it stand awhile before using?
If you let it sit for at least 24 hours before using, it will allow the chlorine and fluoride normally found in municipal water to dissipate first.
Many houseplants handle tap water just fine but some are more sensitive, one sign of a problem is if you find the leaf tips have turned brown (especially for long, thin leaved plants like a spider plant ), this can be a result of using tap water that hasn’t been allowed to sit first. If you water directly from the tap, the chlorine can cause harm to overall growth.
Another benefit to letting it sit for 24 hours: it will be close to room temperature when you use it. Water that is too warm or cold can shock the plant and affect its health so by letting it sit awhile first, the temperature will be just right.
If you have a water filter installed, you won’t need to worry about giving the water time to sit since it will be filtered right from the tap. You can also use bottled distilled water on sensitive plants to avoid problems.
Moving Them Outdoors
Most houseplants love to go outdoors for a vacation in the summer. When the weather has settled down and the nights stay warm is the time to put them out. Look them over first to see if any need to be repotted in larger pots. Don’t plant them right into the soil–they might grow so big you will ruin them trying to pot them again in the fall, or if you succeed, it will be too large for its place in the house. Such things as calla lilies, caladiums and tuberous begonias that grow from a bulb or tuber may be taken from the pot and planted in the ground, for they can always be dug and stored in the fall.
If any need pruning to give them a better shape, do that too before putting them outside. Look them over for insects, and spray if necessary. Lay the pots on sides and do a through job of spraying the underneath sides of the leaves.
Find each a good location that suits its needs. Those that stood away from the sun in the house should be put in shade outdoors–ferns, begonias, sansevierias, philodendrons, ivy, dieffenbachia, caladium, rubber plants, nephthytis, patience plant, peperomia, baby’s tears, spider plant , aspidistra, Christmas cactus  and orchid cactus, hoya, hydrangea , bromeliads, kalanchoe. Those that enjoyed considerable sun indoors should have it outdoors too–the geraniums , coleus, shrimp plant, cacti and succulents , poinsettia , crown of thorns.
Remember that outdoor light is many times brighter than indoor light. It is well to protect houseplants from this sudden increase of light, especially those that are put in the sun. Cheesecloth draped over them for a few days will accomplish the purpose. Protect from wind by putting them in the lee of a building, hedge or wall, or staking them securely.
Most gardeners like to “plunge” their potted plants–that is, they sink them pot and all in soil up to the rim. This method keeps the roots cooler and moister than if pots stayed on top of the ground. To prevent roots from growing through the drain hole and penetrating the soil, put a drainage layer of 2 to 3 inches of gravel or cinders under each pot. Turn the pot in its hole every few weeks, as a further reminder to the roots to stay where they belong. Don’t bury the rim of pot below ground level or roots will go out over the top.
Water occasionally during dry spells, and keep a close watch for insect pests, just as you would if they were in the house.
Source: The Workbasket (June, 1954)