Strawberry production scheduling: variety calendar
Econome à LégumesIn professional strawberry growing, the question of production scheduling is first and foremost a question of profitability. A farm that concentrates its entire harvest into 4 to 6 weeks — the classic pattern of June-bearing varieties in open-field production — simultaneously faces three constraints that are difficult to absorb: a brutal labour peak representing 50 to 70% of variable production costs, local market saturation that drives prices down at the very moment supply is at its highest, and climate risk concentrated in a narrow window where a frost or botrytis episode can wipe out several weeks of production in one go.
The European strawberry market reached €4.87 billion in 2024. France produces around 77,200 tonnes per year, but still imports 62,000 tonnes — largely because domestic production remains concentrated in spring, when Spanish and Moroccan supply has already saturated the supermarket supply chains since January. French strawberry production is not in competition with Huelva on volume and price. It differentiates itself on quality, freshness and seasonality — which requires a consistent, planned and spread-out commercial presence.
Scheduling strawberry production is not an option reserved for large farms with multi-span tunnel structures. It is a strategy accessible through a considered combination of three interdependent levers: variety selection, the plant type used and the growing system employed. When well managed, it allows a harvest window ranging from late April to October-November depending on the region and system, with a labour load spread evenly across the season.
This article describes the physiological mechanisms that structure variety maturity, the concrete harvest windows by segment, the role of protected structures in managing earliness, and the logic behind building a coherent variety mix according to the target market.
What Fraisibot can do that a general guide cannot
Before going into detail, here are a few concrete questions that scheduling raises in real-world conditions — and that no standard calendar can answer for you:
What proportion of early vs late varieties should you adopt based on your outlet — supermarket supply chains with strict size specifications, short supply chains where flavour commands a premium, or pick-your-own operations requiring good fruit visibility on the plant?
Does your cold tunnel advance Gariguette harvest by 10 days or 3 weeks in your specific climate zone, and what does that mean for the optimal timing of your cold-stored plant order?
Is it better to introduce everbearing varieties on raised gutters to cover July to October, or to stick with late June-bearing varieties with annual plant renewal?
These are trade-offs that depend on your soil, your region, your system and your market. Fraisibot, our AI agronomist specialised in strawberry growing, answers these questions taking your specific situation into account, available 24/7 with no appointment needed.
1. The logic of maturity: photoperiodism, vernalisation and variety typologies
Understanding why some varieties concentrate their harvest into 4 to 6 weeks while others produce continuously from May to November is the first condition for building a coherent scheduling calendar. Everything comes down to how the plant responds to day length and winter temperatures.
June-bearing varieties: the short-day logic
June-bearing varieties — known as "short-day" or June-bearing varieties — initiate their floral induction in autumn, when day length drops below a critical threshold (generally 12 to 14 hours depending on the genotype). This induction, combined with winter vernalisation (accumulation of cold between 0 and 7°C), determines the number of flower buds formed in the crown. Flowering will occur the following spring, and harvest will be concentrated within a 4 to 6-week window — with 70% of production hyper-concentrated in the first 3 to 4 weeks of this peak.
The quality of this autumn floral induction directly conditions the yield potential of the following season. A plant that has not accumulated sufficient winter cold — an increasingly common situation in southern regions as a result of climate change — will produce fewer flower buds and therefore fewer fruits, even if all other growing conditions are optimal. This is one of the reasons why cold-stored plants (frigo plants) are so valuable: their storage in cold chambers at -1.5/-2°C artificially completes the cold accumulation and standardises floral induction, regardless of local climate conditions in the preceding autumn.
This mechanism is what makes single-variety June-bearing production so logistically demanding: the entire harvest arrives at the same time, regardless of market conditions.
Everbearing and day-neutral varieties: spread production
Everbearing and day-neutral varieties (insensitive to photoperiod) operate on a radically different logic. Their flowering is not triggered by day length but by temperature: as soon as temperatures rise in spring, the plant enters production and maintains continuous flowering until the first autumn frosts. A well-managed everbearing variety produces from May-June through to October-November, with successive waves of fruiting interrupted by short pauses linked to summer heat peaks (above 32°C, fruiting slows or temporarily stops — a phenomenon to anticipate in the summer harvest calendar, particularly in southern and central regions).
Charlotte, Mara des Bois, Cijosée, Portola, Cabrillo, San Andreas and Albion represent this family. Their instant productivity is lower than a June-bearing variety at its peak, but their total seasonal production is comparable — distributed over 5 to 6 months rather than 5 to 6 weeks. Grown in substrate on raised gutters, their management is facilitated by the ergonomics of harvesting and nutritional control, making them the foundation of the most sophisticated scheduling systems.
Wild strawberries and alpine four-season types
Fragaria vesca, in its everbearing forms (Reine des Vallées, Mignonnette, Alexandria), represents a third logic: very low productivity, tiny fruits, exceptional fragrance. These varieties are only viable as a niche — fine dining, premium markets — with valuation per fruit rather than per kilogram. They contribute to scheduling by their continuous plant presence throughout the season, but do not form a basis for professional volume production.
2. Variety calendar by maturity segment: harvest windows and climate zones
The harvest windows below correspond to a reference lowland growing situation (Atlantic lowlands, Lot-et-Garonne, Anjou regions). Climate-related shifts by zone are shown at the end of this section.
Very early segment: window April – mid-May
Gariguette is the French reference for early production. Harvest starts in the lowlands from mid-April under cold tunnels and extends through to mid-June. A Label Rouge variety in the South-West lowlands, it is prized for its organoleptic profile (acidity, fragrance) but demanding in terms of sorting labour. Its early window gives it a significant price advantage in supermarket supply chains during the first weeks.
Cléry starts slightly after Gariguette, from early May to June. Conical fruit, firm, glossy, highly suited to long-distance distribution. Its regular size and post-harvest shelf life make it a reliable choice for long supply chains.
Allegro fits the same very early slot with strong suitability for cold tunnel growing.
Early to mid-season segment: window May – late June
Ciflorette runs from May to July depending on the zone — a broader window than Gariguette, with a similar aromatic profile but superior firmness. Well suited to short supply chains.
Darselect sits between early and mid-season, from early May to late June. Large, glossy fruit with good firmness. Suited to markets with strict size requirements.
Verdi is a solid mid-season choice, with flavoursome, well-formed fruits, ideal for peak market season.
Mid-season to late segment: window late May – mid-July
Sonata is later than often assumed: its harvest peak falls in late June / early July, with a start around 22 June in lowland conditions. Standard supermarket variety, consistent size, sustained yield.
Elsanta follows a very similar profile to Sonata — concentrated window in May-June depending on region, excellent firmness for distribution, long the European supermarket reference.
Sonsation extends the mid-season with notable disease resistance. Quality fruit, suited to the difficult conditions of late season.
Very late segment: window August – September
Malwina is in a category of its own: an extremely late variety, its harvest occurs in August and September — 2 to 3 months after the Gariguette peak. Large fruit, deep red, glossy, robust. It fills a commercial slot that is often poorly covered by local June-bearing varieties, with grower prices generally better than at peak season. Its hardiness makes it a stable variety in difficult late-summer conditions.
Everbearing segment: window May – October/November
Charlotte, Mara des Bois, Cijosée, Portola, Cabrillo produce continuously throughout the season. Used as a complement to June-bearing varieties, they ensure supply continuity between the windows of short-day varieties and cover the summer period (July-August) when those are absent.
Impact of climate zones on harvest windows
| Zone | Shift vs Atlantic lowlands | Specific notes |
|---|---|---|
| Mediterranean / South | 1 to 2 weeks earlier | Gariguette harvest possible from early April under cold tunnel |
| Atlantic lowlands | Reference | Classic conditions: Anjou, Lot-et-Garonne |
| Continental / Alsace, Burgundy | 7 to 10 days later | Increased spring frost risk |
| Mountain / foothill zones | 10 to 15 days later | Harvest window shifted to August for standard varieties |
3. The role of protected structures in managing earliness
The growing system is not merely a container — it is an active lever for controlling harvest dates. With the same variety and same plant type, shifting from open-field production to a cold tunnel or a heated multi-span structure can move the harvest window by several weeks.
Open field: the uncontrolled window
In unprotected open field, the plant is directly exposed to local weather conditions. The harvest window is the one the variety gives in that zone, with no ability to advance or delay it. This is the system most exposed to risks: flower frost damage from -1°C (pistils destroyed, partial crop loss), massive botrytis in wet spring conditions, summer heat stress on everbearing varieties above 32°C. Peak productivity is often high but temporal concentration is at its maximum — simultaneously generating the most difficult labour peak to manage and the highest risk of local market saturation. In zones with recurring spring frost risk (continental basins of central and northern France), open-field growing without protection is now economically difficult to justify for early-maturing varieties.
Unheated cold tunnel: 7 to 15 days earlier
A standard cold tunnel (multi-span or market garden tunnel, polyethylene film, no heating) provides a thermal advance of +3 to +6°C relative to the outdoors. For a standard June-bearing variety in the Atlantic lowlands, the net earliness gain compared to open field in the same region is measured at between 7 and 15 days. Concretely, a Gariguette that would start in late April in open field starts around 15-20 April under a cold tunnel. In continental zones, the same tunnel allows harvest starting around 20 May rather than late May.
Beyond the simple harvest shift, the cold tunnel changes the farm's risk profile: it protects against flower frost to -5°C (with film closed), significantly reduces botrytis pressure in wet spring conditions, and improves commercial fruit quality — more consistent sizing, clean fruit without soil splashes, better shelf life in distribution. The investment cost of a multi-span tunnel is in the order of €5,000 to €15,000/ha/year in depreciation, making it the first protection investment to prioritise for a grower starting out.
The earliness gain from a cold tunnel may seem limited (7 to 15 days) compared to a heated structure. But commercially, 10 days ahead of the local market at the start of the season often makes the difference between a grower price that covers costs and a premium of 30 to 50% in the first weeks of harvest.
Semi-forced or heated multi-span structure: 3 to 6 weeks earlier
With supplementary heating or a semi-forced structure, the shift reaches 3 to 6 weeks compared to open field. Harvests starting in late March or early April are achievable in temperate zones, repositioning the commercial window outside direct competition with Spanish supply. This is the dominant system in the Netherlands and Belgium, and is growing rapidly in France for the premium supermarket segment.
Substrate gutters: scheduling taken to its maximum
By combining a multi-span structure, substrate growing on raised gutters and day-neutral everbearing varieties, some growers cover a window running from December to November in mild zones. The investment is heavy (€60,000 to €120,000/ha in fixed structure) but total control over the harvest calendar is achieved. An often underestimated operational benefit: the ergonomics of harvesting on raised gutters allows 7 to 15 kg/hour/person compared to 4 to 10 kg/hour in open field, which fundamentally changes the calculation of harvesting costs.
4. Plant type as a lever for controlling harvest date
With identical variety and identical planting date, the choice of plant type can shift the harvest date by 4 weeks. This is a scheduling lever that is often underused.
Cold-stored (frigo) plants: maximum flexibility, long cycle
Cold-stored (frigo) plants (grade A or A+) are produced by autumn lifting followed by cold storage at -1.5/-2°C. They can be planted from January-February for early production under tunnel, or delayed until June for summer cycles in warm zones. Their planting flexibility makes them the primary tool for controlling flowering date: by adjusting planting timing according to local frost risk, the target harvest window can be pinpointed with precision.
The trade-off: frigo plants require approximately 120 days between planting and the start of harvest. This lead time must be factored into the scheduling calendar.
Tray plants: integrated floral induction, short cycle
Tray plants (plug plants grown in substrate trays) are produced in the nursery with floral induction already completed before delivery. After planting, the plant enters production quickly: the time from planting to harvest is approximately 90 days, or 30 days less than a frigo plant planted on the same date.
This 4-week gain is significant within a scheduling calendar. Planted in a cold tunnel in early March, the difference is a harvest starting in early June (frigo plant) versus early May (tray plant). Tray plants are particularly well suited to protected growing with an early harvest target, and to systems where rapid cycle rotation is sought.
Practical application: combining both types to control the calendar
A grower aiming to cover April to July with the same variety (Gariguette, for instance) can combine:
- Tray plants planted in late January under a semi-forced tunnel → target harvest late April / early May
- Frigo plants planted early March under a cold tunnel → target harvest late May / June
With two plant types on the same variety, an intra-variety spread of 4 to 6 weeks is achieved without any need to diversify the commercial outlet.
5. Building the variety mix: allocation logic according to market outlet
Scheduling cannot be decreed — it is designed by starting from the commercial outlet and working back to variety and technical choices. Two farms with identical surface areas can have radically different mixes depending on whether they target supermarket supply chains, short supply chains or pick-your-own.
Supermarket and long-chain distribution: priority on firmness, size, consistency
Supermarket distribution requires well-sized, firm fruits with a minimum post-harvest shelf life of 48 to 72 hours. Organoleptic profile matters less than visual consistency. The appropriate mix is built around June-bearing varieties with staggered windows:
- Gariguette or Cléry for the early slot (April-May), with a price premium
- Darselect or Elsanta for full season (May-June), volume and firmness
- Sonsation or Malwina to extend into July-August with a differentiated offer
- Everbearing varieties (Charlotte, Portola) as a summer complement, under cover to maintain firmness
This type of mix smooths production over 4 to 5 months with regular order fulfilment, without the sharp peaks of a single-variety system.
Short supply chains, farmers' markets and foodservice: priority on flavour, typicity, seasonality
In short supply chains, the customer pays for the organoleptic difference. The mix can feature less firm but more aromatic varieties, with communication built around seasonality:
- Gariguette as the season opener (the hero product)
- Ciflorette or Mara des Bois for full season (differentiated aromatic profile)
- Charlotte or Mara des Bois everbearing for summer and autumn
- Wild strawberries (F. vesca) in very small volumes for fine dining
The early/mid-season/late rotation plus everbearing varieties sustains market presence from May to October.
Pick-your-own: priority on spread, robustness, fruit visibility on plant
Pick-your-own requires fruits to be present and visible on plants throughout the season, with a long enough operating window to make the organisation worthwhile. Everbearing varieties are essential — they ensure continuity from July to October. Late June-bearing varieties (Malwina, Sonsation) complement in August-September.
The labour impact here is the direct inverse of the supermarket scenario: a single-variety system would create an unmanageable 3-week peak, whereas a well-built mix allows a constant workforce to be maintained over 5 months, reducing waste rates linked to over-ripeness (normally 8 to 15% in single-variety peaks) and optimising seasonal employment contracts.
The impact of the mix on labour management: the often overlooked calculation
Harvesting labour represents 50 to 70% of variable costs in strawberry growing. In single-variety June-bearing production, 70% of total output is concentrated within 3 to 4 peak weeks. This is mathematically the most difficult scenario to manage from a workforce perspective: it requires over-recruitment for the peak, managing waste from over-ripeness (8 to 15% of fruits at peak), and then releasing the entire workforce within a few days.
A well-built variety mix reverses this pattern. A farm sequencing Allegro (May), Verdi (June), Sonsation (July), Malwina (August-September) and everbearing Charlotte (May to October) can maintain a relatively stable harvesting workforce over 5 to 6 months, with regular passes every 2 to 4 days on each variety according to its ripening rhythm. Harvesting pace — 4 to 10 kg/hour in open field, 7 to 15 kg/hour in substrate gutter systems — becomes predictable and plannable across the season, rather than concentrated in a 3-week bottleneck.
The consequent improvement in seasonal employment contracts is direct: workers staying 4 to 5 months on the farm are more productive, better trained in variety handling and sorting standards than a workforce recruited and trained at short notice for 3 weeks. This is an operational gain that per-hectare yield data does not capture — but that reads directly on net margin.
A concrete mix for an Atlantic lowland farm targeting local markets and a foodservice circuit:
- Allegro (tray plants, cold tunnel) — harvest May: season opener, early-bird premium
- Verdi (frigo, open field under fleece) — harvest mid-May/June: volume relay
- Sonsation (frigo, open field) — harvest June/July: season extension
- Malwina (frigo, cold tunnel) — harvest August/September: rare slot, premium price
- Charlotte (everbearing, substrate gutters) — May to October: the season's backbone
Result: commercial presence across 6 months, labour peak spread over 5 distinct stages, no week of total market saturation.
Why your variety calendar looks like no one else's
The harvest windows and shifts presented in this article are reference benchmarks. In real-world conditions, the equation that determines your optimal calendar is considerably more complex — and that is precisely where generic guides reach their limit.
Take Gariguette with cold-stored plants under a cold tunnel: in Lot-et-Garonne, harvest starts around 20 April. In Alsace, it starts around 5 May, or even 10 May if the spring is late. This is not a minor detail — it is 15 to 20 days that determine your delivery commitments, your seasonal labour order and your buyer communications.
Apply the same logic to plant type: two growers in the Atlantic lowlands, same Cléry variety, same cold tunnel, same planting date. One uses frigo plants, the other tray plants. The harvest gap between them will be 30 days. This is not a trivial choice — in a local market, 30 days earlier means a grower price potentially 20 to 30% higher in the first weeks, before local competitors come to market in turn.
Add to this: the plot history (Verticillium or Phytophthora presence forces a conversion to substrate growing, which completely changes the variety reasoning), local botrytis pressure in wet spring conditions (which may force harvest passes to 24-hour intervals rather than 48 hours, with major workforce planning implications and a direct impact on team scheduling), the availability constraints of licensed varieties at your usual nursery, or local market saturation on certain dates that makes a concentrated June harvest counterproductive.
And that is before considering climate change, which is progressively reshaping spring frost risk zones and summer heatwave patterns — two hazards that can undermine a carefully planned scheduling calendar if the chosen varieties do not have the thermal tolerance suited to the zone.
No standard variety calendar can make these decisions for you. They require an answer contextualised to your farm, your soil, your zone and your market outlet.
Fraisibot, our AI agronomist specialised in strawberry growing, addresses these trade-offs taking your real situation into account: variety, plant type, climate zone, growing system, plot history. Available 24/7, no appointment, no travel required. Discover all our specialised AI agronomy advisors.
Conclusion: scheduling as an active strategy
Strawberry production scheduling is not the passive result of haphazard variety diversification. It is a strategy built upstream, by articulating three levers coherently: variety selection (earliness, photoperiodism, system suitability), plant type (frigo for flexibility, tray plant for controlled earliness) and growing system (cold tunnel for 7 to 15 days, heated multi-span for 3 to 6 weeks, substrate gutters for total calendar control).
Well built, this strategy transforms the farm's economic profile: labour load spread over 4 to 6 months, reduced waste rates, regular commercial presence, reduced exposure to climate risks concentrated in a short window, and differentiated positioning in early and late slots where local competition is thinner.
To go further in building your variety calendar based on your specific situation — climate zone, market outlet, growing system — Fraisibot supports you step by step in planning your season. Access all our specialised AI agronomy advisors and put your questions directly to Fraisibot, our strawberry expert.