Why does my spider plant have no flowers?

On a spider plant this is a healthy, good sized rosette of leaves that never sends out a flower stalk, and so never produces the plantlets that dangle from it. Year after year there are leaves and roots and no runners.

The most likely cause is a pot with too much room, or too much feed. The entry says a well fed spider plant in a roomy pot puts everything into leaves and produces no runners, while one that is slightly potbound and moderately fed throws them by the dozen. The Royal Horticultural Society lists an overly large pot among the things that can discourage flowering, and the Missouri Botanical Garden notes that excess fertiliser can reduce the number of plantlets.

To confirm it in a minute, tip the plant out and look at the roots. A rootball with plenty of soil around it and room to spare, or roots that have not yet filled the pot, says the pot is generous. Then think about the feed. The entry asks for half strength monthly in the growing season, and anything stronger or more often is too much.

Two other causes are worth ruling out. The RHS says most spider plants will not flower or produce plantlets until they are at least a year old, so a young plant may simply need time. Light and cool temperatures also discourage flowering. The Missouri Botanical Garden adds that plantlet production depends on short days and long, unbroken nights held for at least three weeks, so a plant that is lit late into the evening may not get that.

Expect the change to take a season. After a spell slightly potbound and lightly fed, in good light, the stalks appear in the next growing period, and the plantlets form on them.

What this plant wants

The fix

Leave it slightly potbound and halve the feed. Spider plants throw runners when they are comfortable but not indulged.

Read on

It will not flower

The same sign on any plant, with the causes in the order they are likely.

Spider plant care

Light, water, feeding, repotting and the rest of the entry.

Check it in the diagnoser

Opens with the plant, the part and the sign already chosen.