Saffron May Not Bloom Until Fall

QUESTION: I just planted a bunch of mail-order saffron crocus (so I could harvest my own spice), and none of them is blooming. Did I plant them too late?

--J.B., Pacific Palisades

ANSWER: Even an October planting of this fall-flowering bulb should have bloomed. If you planted later than that, the flowers may have “aborted,” according to Dan Davids of Davids & Royston Bulb Co. They were there--inside the bulb--but didn’t open.

Or the bulbs may have been too small to bloom their first year. Davids imports bulbs that are 12 centimeters in diameter or larger, and these will bloom the first year. Any smaller and they might not, and mail-order sources sometimes sell the smaller bulbs.

Crocus sativus will readily grow and naturalize in Southern California, so it may bloom next fall. However, “it is a difficult bulb to flower,” even though it makes leaves reliably, says Baldwin Park bulb expert Charles Hardman, with the International Bulb Society. He says that even where they are grown commercially in Spain, they don’t always flower.

He suggested some tricks that might help, starting with planting the bulbs much deeper than recommended. Try making the hole five to seven inches deep, instead of the normally recommended two to three inches. Add a touch of straight potassium sulfate fertilizer to the hole and feed in small doses several times during the growing season. Or add a sprinkling of wood ashes to the soil surface. Don’t use a fertilizer that contains nitrogen.

With any luck, you’ll get blooms next year, but Hardman suggests planting a lot, as you apparently did, so at least a few will flower. The source of the spice saffron is the orange-red stigma inside the flower, so it must bloom if you wish to cook with it.

Don’t dig them up after the foliage fades in spring, but keep their beds on the dry side. Be sure they are planted in full sun.