Rethinking the Allotment: Why the UK Growing Calendar Needs to Change
For generations, the British allotment calendar has been built around a fairly dependable assumption: spring warms gradually, summer is pleasantly warm rather than intensely hot, rain arrives reasonably regularly, and the main growing season runs from spring through to early autumn.
That assumption is becoming much less reliable.
Summer 2026 was provisionally the warmest UK summer on record for mean, maximum and minimum temperatures, breaking a record set only the previous year. The five warmest UK summers in the Met Office's series have now all occurred since 2003.
Perhaps more strikingly, by the end of summer 2026 there had been 33 days when somewhere in the UK exceeded 30°C, compared with 22 during the famously hot summer of 1976. Temperatures reached 35°C during May, June, July and August - the first time this has happened. But for anyone growing their own food, temperature tells only part of the story. Heat has increasingly been accompanied by prolonged dry periods. England and Wales experienced their driest Julys on record in 2026, while southern England recorded its driest calendar month on record.
For gardeners and allotment holders, the consequences are very practical: dry soil, rapidly emptying water butts, plants bolting before they can be harvested, flowers failing to set fruit and crops requiring far more irrigation. The British allotment isn't disappearing. But the calendar it was built around may need to change.
High summer is becoming the difficult season
Traditionally, summer has been regarded as the easiest part of the vegetable-growing year. Increasingly, it may make more sense to think of the hottest part of summer as a period that needs managing.
Many familiar vegetables prefer relatively cool growing conditions.
Lettuce and spinach can bolt rapidly during hot, dry weather, producing flowers and becoming bitter rather than continuing to produce tender leaves.
Peas prefer cooler conditions and can struggle to flower and set pods during prolonged hot weather.
Brassicas such as broccoli and cauliflower can also respond badly to heat and water stress, particularly when plants are trying to establish or develop heads.
Even runner beans - one of the great stalwarts of the British allotment - can temporarily stop setting pods during very hot weather.
This doesn't mean we should stop growing these crops.
It may mean we need to stop assuming that June, July and August are automatically the best months in which to grow them.
Change the calendar before changing the crop
One of the simplest responses to hotter summers is not necessarily to grow completely different vegetables, but to change when familiar ones are grown.
Cool-season crops such as peas, lettuce and spinach can increasingly be treated as spring and autumn crops. Sow them early enough to produce a harvest before the hottest weather arrives, then sow another crop towards the end of summer as temperatures begin to fall.
Instead of one continuous growing season, the allotment year starts to look more like three distinct periods:
Spring — cool-season crops
Peas, lettuce, spinach, radishes, early carrots and other crops that enjoy cooler conditions.
High summer — heat-tolerant crops
Tomatoes, peppers, chillies, aubergines, courgettes, squash, beans and other plants better able to cope with sustained warmth.
Late summer into autumn — cool-season crops again
Lettuce, spinach, oriental greens, radishes and other fast-growing vegetables can return as temperatures moderate, while winter crops continue developing.
The traditional growing calendar doesn't disappear. It becomes more flexible.
Give more space to crops that enjoy the heat
Hotter summers also create opportunities.
Tomatoes, peppers, chillies and aubergines historically needed the warmest and most sheltered parts of a British garden to perform reliably. Increasing summer temperatures can provide much more favourable conditions.
Courgettes, pumpkins and winter squash can also thrive in warm weather, although they still require substantial amounts of water.
More adventurous growers might consider crops that until recently would have seemed unusual on a British allotment.
Sweet potatoes need a long, warm growing season and are increasingly feasible in warmer parts of the UK.
Okra is another possibility. It still requires considerable warmth and isn't about to replace runner beans across Britain, but increasingly warm summers make experimentation more realistic.
Heat-tolerant leafy vegetables are worth exploring too.
Chard generally withstands summer conditions better than spinach, while New Zealand spinach provides edible leaves through warmer weather without behaving like traditional spinach.
Amaranth and orache offer further possibilities for growers willing to experiment.
The allotment of the future doesn't necessarily have to become Mediterranean. But the balance of what occupies it during July and August could look increasingly different.
Heat tolerant doesn't necessarily mean drought tolerant
There is an important distinction.
A plant that enjoys hot weather isn't necessarily a plant that can survive with little water.
Courgettes and squash thrive in warmth but can be extremely thirsty. Tomatoes cope well with high temperatures but inconsistent watering can cause problems with fruit development. Aubergines and peppers still need adequate moisture to produce worthwhile crops.
True drought-adapted plants are rather different.
Established rosemary, thyme, sage and oregano are naturally adapted to relatively hot, dry conditions. Globe artichokes develop substantial root systems, while established perennial crops such as asparagus can access moisture from deeper in the soil than many shallow-rooted annual vegetables.
So growers increasingly need to ask two separate questions when choosing plants:
Can this crop tolerate heat?
And:
How much water will it need when that heat arrives?
Variety may become as important as vegetable
Changing climate doesn't necessarily mean changing crops altogether.
It can also mean changing varieties.
Seed catalogues increasingly deserve closer attention. Characteristics such as slow to bolt, bolt resistant, heat tolerant, drought tolerant and early maturing may become more important considerations when choosing seed.
Two varieties of the same vegetable can respond quite differently to stressful growing conditions. Early-maturing varieties can also offer another advantage: getting a crop harvested before the most intense summer heat arrives. For allotment growers accustomed to buying the same trusted varieties every year, experimentation may become increasingly worthwhile.
Rather than replacing everything that has traditionally worked, dedicate a small part of the plot each year to varieties designed for warmer or drier conditions and see what actually performs best.
Don't write off brassicas - move them out of the heat
Cabbages, kale, Brussels sprouts, cauliflower and purple sprouting broccoli remain valuable allotment crops. But trying to establish or mature some brassicas during the hottest part of summer can become increasingly difficult. The answer may be to concentrate more brassica production into cooler periods, particularly autumn and winter. That doesn't eliminate every problem. Warmer winters, heavy rainfall, waterlogging and changing pest pressures create challenges of their own. But the broader principle remains useful: instead of expecting every traditional crop to cope with high summer, arrange the growing year so that heat-sensitive plants spend as little time as possible at their most vulnerable stage during extreme temperatures.
Water could become the allotment's most valuable resource
Changing what we grow will achieve relatively little if we don't also change how we manage water. Water conservation is likely to become one of the defining skills of productive vegetable gardening. Rainwater collection is an obvious starting point, but a single water butt can disappear surprisingly quickly during a prolonged dry spell. Where space and allotment rules allow, increasing storage capacity makes sense.
So does improving the soil itself.
Adding compost and other organic matter improves the ability of soil to retain moisture, while a substantial layer of mulch helps reduce evaporation and keeps the soil surface cooler.
Watering technique matters too.
Frequent light watering encourages roots to remain near the surface, where the soil dries fastest. Less frequent but thorough watering can encourage deeper rooting and make plants more resilient.
Grouping thirsty plants together can also make irrigation more efficient.
Raised beds deserve particular attention. Their improved drainage is extremely useful during wet winters, but the same characteristic can cause them to dry rapidly during hot summers. Adding organic matter and keeping the soil covered with mulch therefore becomes particularly important.
Shade may become a gardening tool
British gardeners have traditionally spent considerable effort trying to maximise sunshine.
Increasingly, we may sometimes need to do the opposite.
Temporary shade netting can protect lettuce, young brassicas and other vulnerable vegetables during periods of extreme heat.
Taller plants can also provide useful shade.
Instead of treating every vegetable as an isolated crop, allotment layouts could increasingly be designed around creating small microclimates — allowing taller crops such as beans, sweetcorn or sunflowers to provide afternoon shade for more vulnerable plants nearby.
The objective isn't to turn the allotment into a shaded garden.
It's to recognise that uninterrupted summer sunshine isn't always beneficial.
A different way to think about the allotment
Perhaps the biggest adjustment is psychological.
For generations, British vegetable gardening has largely been about capturing as much of our relatively short summer as possible.
The emerging challenge may be different.
We may increasingly need to protect crops from parts of the summer.
That means thinking about the allotment not simply as a collection of vegetables but as a system: planting dates, varieties, soil condition, shade, water storage and crop choice all working together.
There will also be considerable regional variation. A grower in Kent may face very different summer conditions from someone growing vegetables in northern England or Scotland. One exceptionally hot summer doesn't mean every future summer will look the same either.
The objective isn't to predict exactly what the weather will do. It's to build a plot that is more resilient when extremes occur.
The allotment calendar is changing
None of this requires abandoning peas, runner beans, cabbages or lettuce — and it certainly doesn't mean that every British allotment needs to fill up with okra and sweet potatoes.
It means becoming more adaptable.
Sow cool-season crops earlier and later. Choose varieties that resist bolting and cope better with heat. Give more high-summer space to vegetables that enjoy warmth. Experiment with unfamiliar crops. Improve the soil's ability to retain moisture. Capture more rainwater. Mulch heavily. And be prepared to provide shade when temperatures become extreme.
The British allotment remains an extraordinarily productive way of growing food.
But the assumptions behind it are changing.
The traditional allotment calendar was built around the British climate. As that climate changes, the calendar will have to change with it.
