If autumn came and went without a saffron flower, the corms are usually alive. The question is which of two situations you have: grassy leaves but no flowers, which is nearly always a corm that is not yet big enough, or nothing above ground at all, which is usually rot, a rodent, or a corm that is simply running late. Both are worth diagnosing before you dig anything up.
You have leaves, but no flowers
This is the common one, and it is the better of the two. Green growth means the corm is alive and working. Three things explain almost all of it.
The corm was too small
Saffron corms need to reach a certain size before they will flower. Below roughly two centimetres across, a corm generally puts everything into leaves and skips flowering entirely. It is not a fault, it is the plant building capacity.
What to do: leave the leaves completely alone. Those leaves are how the corm bulks up, and cutting them back is the surest way to guarantee no flowers next year either. A light, low-nitrogen feed every few weeks while the leaves are actively growing through winter helps. High-nitrogen fertiliser does the opposite, pushing leaf growth at the expense of flowers.
It was their first season
Newly planted corms are often lifted, dried, transported and replanted in a single season, and some respond by settling in rather than flowering. Trial data backs this up: in the first year after planting, only around half the corms typically flower at all, and those that do usually manage a single flower each.
What to do: nothing. Keep the leaves fed and watered through winter and let them die back naturally. Second and third years are usually much better.
Not enough sun
Saffron flowers in response to a warm, dry dormancy followed by cooling autumn conditions. A shaded position through summer can leave the corms without the warmth that sets flowering up.
What to do: mark the spot now and move them in summer when they are dormant, into full sun. If they are in a pot, just shift the pot.
You have nothing at all
No flowers and no leaves by the end of May means something needs checking. Work through these in order.
They may simply be late
In cooler districts, the Blue Mountains, Tasmania, the tablelands, emergence can run later than the books suggest. Scrape back two or three centimetres of soil above a corm. If you find a pale shoot tip, cover it over and leave it be.
Rot, which is the usual answer
Saffron comes from dry summer climates and will not survive a wet dormancy. Heavy soil, a rainy summer or a bed that gets watered along with everything else around it will rot the corms while they sleep.
The test: if there is still nothing by June, lift one corm and squeeze it. Firm means healthy and dormant, so replant it. Soft, mushy or smelling sour means it has rotted, and the rest are likely the same. Next time, use a pot or a raised bed with sharp drainage, and keep them dry from about November through to January.
Something ate them
Rats, mice and bandicoots will dig up and eat saffron corms. If you dig where you planted and find nothing at all, no corm and no rot, that is usually the explanation.
What to do: grow them in pots, or lay wire mesh just under the soil surface over the planting.
Before you give up on them
Saffron is perennial and it multiplies. Even a season without flowers is not a wasted one, because a corm with healthy leaves is producing offsets underground. A planting of three corms can quite reasonably be six or nine when you lift it, and those are next year's flowers.
The routine that gets you there is simple: feed lightly while the leaves are up, keep the soil just moist through winter, let the leaves yellow and die back on their own in spring, then keep the corms dry all summer.
Worth knowing. Colchicum autumnale, sold as autumn crocus or meadow saffron, looks similar and flowers at a similar time, but it is poisonous and produces no culinary saffron. Only Crocus sativus gives you the spice.
Frequently asked questions
Should I dig them up to check?
Only if there has been no growth at all by June. If you have leaves, leave them where they are. Lifting a corm mid-season sets it back.
Can I make a small corm flower this year?
No. Feeding the leaves helps it reach flowering size for next season, but nothing will bring a flower out of an undersized corm in the current year.
How often should I divide them?
Every three to five years, or whenever flowering drops off in a crowded clump. Lift in summer while dormant, separate the offsets, and replant the largest.
When exactly should the flowers appear?
April or May in most of southern Australia, a little later in cold districts. Each flower lasts a day or two, so check daily once they start.
I cut the leaves off by mistake. What now?
Leave the corms undisturbed, keep them just moist for the rest of winter, and expect a weak season next autumn. They usually recover the year after.
Related growing guides
- Growing saffron in pots
- Five ways to use your saffron harvest
- Sandy, clay or loam? Understanding and improving your soil type
Ready to plant? Browse our Saffron Corms.
First-year flowering rates follow University of Vermont and Penn State Extension saffron trial data.