Crocuses are blooming early – here’s what this means for nature
Amid the wet and grey gloom of February, gardeners across the UK are reporting that crocuses are pushing through their lawns and borders weeks ahead of schedule. This phenomenon is no quirk of nature. Crocuses flowering early in 2026 is a sign of shifting seasons, driven by a unique combination of biological triggers and record-breaking UK weather patterns.
Crocuses are thermoperiodic plants, which means they rely on temperature cues rather than day length to dictate their lifecycle. Their corms (a type of bulb) also usually need a cold spell in autumn to prompt an annual reset before they will start to grow toward flowering around March.
Do the seasons feel increasingly weird to you? You’re not alone. Climate change is distorting nature’s calendar, causing plants to flower early and animals to emerge at the wrong time.
This article is part of a series, Wild Seasons, on how the seasons are changing – and what they may eventually look like.
In a typical year, this process unfolds gradually. But if soil temperatures stay mild in autumn and through December and January, as they have this winter, the reset button is not hit and crocuses can reach their flowering threshold far sooner, emerging in late January and early February rather than March.
No cold reset usually means a “blind” corm – a corm that produces leaves but no flowers. That might be expected this year, although the prior weather the UK has experienced may mitigate this.
The past two years have perfectly primed bulbs already in the ground. The year 2024 was the UK’s fourth warmest year. And last year was the UK’s warmest year on record, featuring a scorching summer and exceptional sunshine, enabling crocuses to stockpile massive energy reserves in their bulbs.
Met Office data shows the UK has three weeks fewer ground frosts annually compared to 50 years ago, preventing some plants that grow from bulbs entering their normal state of dormancy over winter. There may be more blind bulbs and corms if this trend continues.
In 2022 researchers showed that UK plants flower a full month earlier than they did before 1987. The Botanical Society of Britain and Ireland’s 2026 New Year Plant Hunt confirmed this, with participants spotting wildflowers and spring bulbs blooming unexpectedly in January. This is a visible signal of climate disruption. Crocuses, being more sensitive than trees or shrubs, act as canaries in the coal mine for spring shifts.
There are other influences beyond climate change that may amplify this early flowering.
Urban heat-island effect
City plants can bloom days earlier than rural ones. Concrete and asphalt trap daytime heat, radiating it overnight, which elevates local soil temperatures. Each 1°C November-December rise adds to around 2.5 more species flowering earlier in the UK.
Light pollution
Light is fundamental to plant growth. Light pollution in cities may mimic longer days, disrupting plant circadian rhythms and prompting bulbs into earlier bud-burst.
Soil microbiome
Complex soil microbe communities that thrive in warmer weather may boost flowering. Mycorrhizal fungi and bacteria form connections with plant roots that can benefit the plant. They respond to warmer soils, too, and support plants’ natural processes and accelerating growth. So warmer winters, induced by climate change, may enhance these associations. Crocuses respond particularly well to this kind of association.
Gardener’s choice
Some growers prefer varieties that flower earlier in the season, and certain species – like Crocus chrysanthus – can bloom two weeks ahead of the more common Dutch hybrids (C vernus).
Energy reserves
The more sun and warmth the bulb gets the previous summer the more energy it stores – and the more energy it has in reserve, the earlier it can flower.
This early crocus bloom may seem delightful after months of drab grey winter, but gardeners should be wary of weather reversals. Buds and flowers are more exposed if colder conditions return, meaning they may whither. Early waking pollinators like bumblebees may benefit from the unusually early feast but these kinds of abnormal timings could disrupt ecosystems outside of gardens.
Spring seems to have arrived early in 2026. As crocuses begin to carpet lawns and borders prematurely, they underscore nature’s sensitivity to our warming world. Their purple and yellow petals, pushing through in January and February rather than March, are as clear a signal as any thermometer.
Lionel Smith does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.