When to Repot and Propagate Spider Plant

Repotting: any season, guided by the roots

Spider plants have no dormant season that makes one month better than another for repotting. Clemson Extension says you can repot at any time of year, and UF/IFAS suggests a schedule of once a year while the plant is young and every other year once it is mature.

The roots matter more than the calendar. Spider plants grow thick, fleshy, tuberous roots that store water, and Clemson warns they can crack a container as they expand. Repot when you see:

• Thick white roots pushing out of the drainage holes or bulging above the soil.
• A pot that has started to bulge, deform or crack.
• For a young plant, a year since the last repotting; for a mature one, two years.

Use a general-purpose potting soil with good drainage, and a pot with drainage holes that is only a little wider than the root mass. If the clump is very large, divide it instead: slide it out, separate it into sections that each have leaves and roots, and pot each one.

Hold off on fertilizer after repotting. Clemson recommends waiting four to six months before feeding a newly potted plant.

Propagating: whenever plantlets appear

Plantlets can be rooted at any time of year, Clemson says, but you will have the most to work with after fall. NC State explains that the plantlet-bearing stems form only after the mother plant gets short days with long, uninterrupted nights, meaning less than 12 hours of light a day, for at least three weeks. That timing means most new stems follow the shortening days of fall.

Plantlets root easily on contact with soil. Pin one onto a small pot of moist mix next to the mother plant and cut the connecting stem once it has rooted, or cut off a plantlet that already shows small roots and pot it on its own. Division of the mother plant, described above, also works in any season.

If no plantlets form by winter, check two things. A plant that gets lamp light late every evening may never see three weeks of long nights. And NC State notes that overfeeding reduces plantlet production.

When to move it outdoors for summer

A summer outdoors in the shade can refresh a tired spider plant, but wait for warm nights. Sources set the threshold at different points:

• University of Maryland Extension: put houseplants out only after night temperatures stay above 60°F, which it says is usually mid-May or early June in Maryland.
• Colorado State University Extension: wait until nights are above 50°F and all danger of frost has passed.
• UF/IFAS, for spider plant specifically: temperatures below 55°F are too cool.

For spider plant, waiting until nights stay above 55 to 60°F is the safer choice. A frost-free night is not enough; go by the low temperatures in your forecast.

Start the plant in full shade. Maryland Extension advises acclimating houseplants to the brighter outdoor light gradually, and Clemson warns that midday sun scorches spider plant leaves. A covered porch or the shade of a tree is ideal. Outdoors it will dry out faster, so check the soil more often.

When to bring it back inside

Bring it in before fall nights get cold. Maryland Extension recommends moving houseplants back as nights begin to drop below 60°F, usually mid-September there. Colorado State says to bring plants in before any danger of frost. Given the UF/IFAS 55°F limit, do not wait until frost is in the forecast.

Inspect the plant before it comes indoors. Outdoors, aphids, spider mites and scale are held in check by beneficial insects, Maryland Extension notes, but they can multiply quickly inside. Check leaf undersides and the base of the leaves, and look at the soil and drainage holes, where Colorado State says slugs and pill bugs hide. Maryland Extension suggests treating plants with a labeled insecticidal soap or horticultural oil before bringing them in.

Once inside, put it a few feet back from cold windows for winter and water less.

Florida and other frost-free areas

NC State lists spider plant as hardy outdoors in zones 9-11, but in Florida UF/IFAS no longer recommends planting it in the ground because its assessment predicts the plant will become invasive in North, Central and South Florida. Florida gardeners can keep a potted plant on a shaded patio year-round instead.