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How to Care for House Plants

Potting House Plants

Repot house plants at least once a year, preferably in the spring. Fast-growing house plants may require repotting two or more times a year.

One sign that a house plant needs repotting is when it begins to wilt only a few days after a thorough watering. House plants should also be repotted when they threaten to tip over (put these into clay pots or use a heavy potting mix). When a white or yellowish crust begins to build up on the plant’s stem and pot rim, indicating an excess of mineral salts, it is also time to repot.

Pots should have drainage holes so that excess water can drain out.

House plants that are difficult or impossible to repot -- a tree-sized plant, for example -- should be top-dressed annually. This simply means scraping off the top inch of potting mix and replacing it with new mix. This procedure will help remove any toxic mineral salts that have built up.

How to Repot

Tip the plant upside down, holding its stem and rootball firmly. If it does not slide out on its own, run a knife around the inside of the pot to loosen the rootball. With a pencil or your finger, remove up to one third of the original potting mixture from all around the rootball, gently teasing it loose. Trim off any dead or damaged roots. For repotting, choose a clean pot no more than one or two sizes larger than the previous one. If the plant has reached its full size, don’t increase the pot size. Pour enough potting mix into the bottom of the new pot to bring the plant up to its original height. Center it well and fill in the empty space with growing mix. A thorough watering will help the plant adjust to its new home.

Newly repotted house plants should be kept out of bright sun for a week or two.


House plants don’t need soil for healthy growth: As long as their roots receive oxygen and moisture, they will thrive. In hydroculture, plants are grown in water using an inert medium such as clay pellets or pebbles as an anchor. A water level indicator tells exactly when to add water, often only once every few weeks. Nutrients are supplied in the form of slow-release pellets or tablets. Although rooted plants can be transferred to hydroculture by thoroughly rinsing their roots of all soil, it is usually easier to start plants from cuttings. Complete hydroculture kits are available for all sizes of plants.

The Right Pot for the Job

Plastic pots (and other containers made of nonporous material) dry out slowly and are ideal for house plants that like their soil kept evenly moist. House plants preferring drier soil will do better in clay pots, since these allow water to evaporate, reducing the danger of overwatering.

All pots should have drainage holes so excess water can be evacuated. Decorative pots without drainage holes can be used, but only as an outside container.

Potting Mixes for House Plants

Most house plants thrive in ready-made all-purpose potting mixes. Most modern mixes are soilless, made of peat moss, vermiculite, and perlite in various proportions. They are light and well aerated, yet hold moisture well, making them ideal for plant growth.

Asparagus ferns, caladiums, Boston ferns, and many other plants prefer this potting mix. Soil-based mixes are heavier and drain more rapidly. They make good choices for cacti and succulents.

Finally, certain indoor plants, such as cattleya orchids and Venus’s fly-traps, normally grow on trees in the wild and require very well-aerated mixes. They are often grown in fast-draining mixes such as sphagnum moss, bark chips, or special epiphyte mixes.

In the next section, we'll talk about temperature for house plants.

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