Strawberry planting: dates and densities

Strawberry planting is arguably the single decision that most determines an entire production campaign. It sets the harvest calendar, determines yield potential, and commits the grower for 3 to 5 years on the same plot. Yet it is often treated as a seasonal reflex: "we plant in August." That approach suits the amateur gardener. It does not suit a professional strawberry grower.

The reality on the ground is more demanding. The optimal planting date depends on the plant type used, the variety selected, the growing system in place — open field, tunnel, soilless substrate — and the commercial target. A planting date based on a generic guide, without factoring in these variables, means risks on earliness, a sub-optimal first-year yield, and sometimes a production cycle misaligned with a market window.

This article treats strawberry planting for what it is to a professional: an agronomic and economic decision. We cover the available plant types and their calendar implications, the logic of backward planning from harvest target, soil preparation as a 5-year investment, and planting densities differentiated by growing system.

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Professional plant types: cold-stored, fresh runners and tray-plants

The first lever for planting date is the plant type. Three categories are used in professional strawberry growing, each with its own windows, technical requirements and fit to growing systems.

Cold-stored plants (frigo)

Cold-stored plants are runners from the previous year, lifted in dormancy in autumn or winter and held in cold storage until use. They are supplied bare-root — also called "crowns" — and establish immediately after planting, with no extended acclimatisation period.

Crown diameter is a critical selection criterion. In commercial production, grade A+ (crown ≥ 15 mm) is recommended: it guarantees superior establishment vigour and a higher first-year yield potential than grades A or B. On markets where first-year production represents immediate economic value, the premium for A+ grade is easily justified.

The planting window for cold-stored plants extends from March to August depending on the objective. A March–April planting of cold-stored everbearing varieties delivers a harvest in the same year. For non-everbearing varieties, cold-stored plant planting typically falls between March and May, for a concentrated spring crop the following year. Summer plantings of everbearing cold-stored plants (July–August) yield an autumn harvest within the same season.

Before planting, rehydrate the plants by soaking them in water for 15 minutes once defrosted. This step restores root moisture and improves establishment. Bare-root fresh runners must be planted within 48 hours of lifting: beyond that, establishment rates drop sharply.

Fresh runners

Fresh runners are young rooted stolons, lifted from the nursery in July–August and replanted immediately. Their use is centred on non-everbearing varieties, for which floral induction must occur in the autumn of the planting year in order to ensure abundant fruiting the following spring.

The professional rule is clear: fresh runner planting takes place in the first two weeks of July for non-everbearing varieties. A plant set at this date has time to establish roots, build reserves, and induce its flower buds under the short days and cool temperatures of autumn. Delayed planting compresses this induction phase, with direct consequences for the number of flower trusses formed — and therefore for the harvest yield the following season.

For a detailed guide to managing this specific growing pathway, see the article Fresh runner strawberry growing pathway.

Tray-plants (waiting bed / WB)

Tray-plants — also called waiting bed plants or WB plants — are plants raised in the nursery during the preceding summer, which have already undergone floral induction before being lifted in autumn and placed in cold storage. Unlike fresh runners or standard cold-stored plants, tray-plants carry an immediately available flowering potential from the moment they are planted.

This makes them the reference plant type for two objectives: very early out-of-season production in cold or heated glasshouses, and short-cycle soilless growing in elevated gutters. In cold glasshouse conditions, the plant-to-harvest cycle with tray-plants can be reduced to 60 days, compared with 90 to 120 days with standard cold-stored plants. This cycle compression opens up opportunities for double annual production on well-equipped operations.

In cost terms, tray-plants are significantly more expensive than the other types. Their use is justified when the price premium on early or out-of-season markets covers the additional investment in plant material.

For a detailed guide to the tray-plant growing pathway, see Tray-plant strawberry growing pathway.

Summary table: plant type × objective × planting window

Plant type	Main use	Planting window	Expected harvest	Key points
Cold-stored grade A+	Non-everbearing, open field / tunnel	March – May	Spring year N+1	Check lot vernalisation; soak 15 min before planting
Cold-stored grade A	Everbearing, all zones	March – August	Summer / autumn year N	Lower grade = slower establishment
Fresh bare-root runners	Non-everbearing, southern and western France	First two weeks of July	Spring year N+1	Plant within 48h of lifting
Tray-plant (WB)	Soilless / cold glasshouse / early production	Autumn (Sept.–Oct.) or late winter	From 60 days after planting	High cost — justified on early-season premium markets

Vernalisation: the invisible factor in plant selection

A parameter frequently underestimated in plant type selection and planting date decisions is vernalisation. Non-everbearing varieties need to accumulate a certain number of cold hours — below 7°C — to correctly break dormancy and develop their reproductive organs. This cold requirement is genotype-specific.

Professional reference values are as follows:

Variety	Cold requirement (hours < 7°C)
Dream	600 – 650 h
Gariguette, Ciflorette, Sibilla, Murano	800 h
Cléry, Dély, Joly, Magnum	1,000 h

A cold-stored plant from an insufficiently vernalised lot will produce aborted or severely delayed flowering, even when planted on schedule. This risk is most acute in mild winters or with plant lots sourced from southern production zones where cold accumulation is structurally lower. At the time of ordering, verify with the nursery the cold hour total recorded for the lot.

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Backward planning: from harvest target to planting date

The professional logic of planting planning does not start from an average calendar — it starts from the target harvest date and works back to the planting decision. This approach, standard in commercial planning, is virtually absent from the guides available online, which all remain anchored to averages.

South-West and South-East France: early production as a commercial lever

In the South-West (Nouvelle-Aquitaine, Lot-et-Garonne, Dordogne) and South-East (Provence, Rhône Valley) growing regions, which together account for more than 50% of national production, harvest of non-everbearing varieties can begin as early as mid-May in open field, and several weeks earlier under tunnel.

Concretely, in these basins, the critical flowering stages (BBCH 55–65, from first visible buds to full bloom) are reached from late March to mid-April in open field. Fresh runner planting must therefore take place in the first two weeks of July of the previous year to allow autumn floral induction. For cold-stored plants, a March–April planting in these basins delivers a summer or autumn harvest depending on variety and system.

Under low tunnels, the thermal gain generated (+3 to +6°C above ambient) shifts stages approximately 3 to 6 weeks earlier. This advantage makes it possible to target harvests from late April, or even early April for the most competitively positioned early-season operations.

Loire Valley and Brittany: the covered growing expertise

In the Centre-West growing regions (Loire Valley, Brittany), the oceanic climate imposes a later open-field harvest — late May to mid-June for non-everbearing varieties. Flowering (BBCH 60–65) typically concentrates in April through to early May.

These regions have developed strong technical expertise in covered growing (multi-span tunnels), precisely to offset this natural climatic lag and offer locally grown strawberries earlier in the season. Fresh runner planting in the first two weeks of July remains the rule for non-everbearing varieties; the covered structure then drives the harvest window.

Northern France and higher-altitude zones: tunnels as a technical requirement

In northern zones and altitude areas above 600 m, the lag compared with southern basins can reach 7 to 15 days on phenological stages. Harvest of non-everbearing varieties begins in June–July, with a shorter productive season in open field.

In these zones, tunnel coverage is no longer a commercial competitiveness lever — it becomes a technical requirement. Without protection, the risk of late spring frost on open flowers (BBCH 60–65) is high: floral organs are damaged from -0.5°C at anthesis, producing the classic "black heart" and misshapen fruit with no commercial value. Furthermore, excessively late plantings — beyond mid-September for fresh runners — leave insufficient time for root establishment before the first cold spell, compromising winter survival and the following year's production.

Switzerland, Belgium, the Netherlands: three complementary models

For French-speaking European growers — particularly Belgium and Switzerland — climatic constraints impose distinct growing pathways.

In Switzerland, production is mainly conducted in open field during the summer on the plateau, with plastic tunnels to advance the spring harvest by 2 to 4 weeks and protect fruit from wet weather. The objective is to supply local markets from May–June despite an alpine climate that naturally delays stages by 10 to 15 days compared with the French lowlands. Cold-stored plants dominate; tray-plants remain less widespread than in Dutch or Belgian models.

In Belgium and the Netherlands, the dominant model is radically different: heated glasshouse, soilless growing, with supply from March–April through to November. These countries have built their competitiveness on mastery of closed-structure climate control and soilless closed-circuit fertigation. The planting window is entirely driven by commercial strategy — the pedoclimatic constraint is virtually absent from their planning logic.

Soilless elevated gutters: breaking free from the natural cycle

The soilless elevated gutter system, in rapid development in France, operates on a different logic. With tray-plants or mini-plug plants, the production cycle can be programmed independently of pedoclimatic constraints. In cold glasshouses, a plant-to-harvest cycle of 60 days is achievable. Double annual production becomes an accessible objective for operations with the corresponding technical expertise.

The planting window in soilless systems is therefore less driven by climate than by the commercial strategy of the operation. This decoupling is both a competitive advantage and a source of technical complexity: mastery of nutrition, substrate moisture and glasshouse climate management becomes the primary performance lever, where it is the planting date that plays that role in soil-grown production.

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Soil preparation: a 5-year investment decision

A professional strawberry bed remains productive for 3 to 5 years. Every decision made before planting conditions the entire cycle. Soil preparation is not a technical step — it is an investment.

Essential pre-planting analyses

Before any planting, a complete soil analysis is essential. The professional minimum covers: pH, organic matter, P₂O₅, K₂O, Mg/K ratio, active lime. This last parameter is particularly critical for strawberry: above 5% active CaCO₃ (ideally < 2%), the risk of iron chlorosis increases sharply, with direct consequences on fruit size and colour.

Beyond the standard physico-chemical analysis, two phytosanitary analyses are systematically recommended before any permanent planting:

• Quantitative Verticillium PCR: Verticillium wilt (Verticillium dahliae) is one of the most damaging soilborne pathogens in strawberry. An established infection is extremely difficult to manage once the crop is in place. Quantitative PCR measures the inoculum load in the soil before planting and allows genuine risk assessment.
• Nematode count (Pratylenchus, Meloidogyne): phytoparasitic nematodes weaken the root system and act as virus vectors. Their presence at high levels may justify delaying planting or moving to a different plot.

For a detailed breakdown of soilborne pathogens and their favourable conditions, see the article Soilborne diseases in strawberry.

Crop rotation: the 5 to 7-year rule

Strawberry should not return to the same plot for 5 to 7 years. This rule is not conservative — it is economically justified by the cumulative parasitic pressure generated by early return.

High-risk previous crops to avoid before strawberry planting include: Solanaceae (tomato, pepper, aubergine), cucurbits, and alfalfa. These crops are favourable hosts for Verticillium dahliae and several species of phytoparasitic nematodes. A previous tomato crop on the target plot should systematically trigger a Verticillium PCR test, regardless of how long ago the crop was grown.

For operations integrating longer rotations or wishing to explore agroecology levers (biofumigant cover crops, cover diversity), see Strawberry agroecology: rotation and mulching.

Soil tillage and ridge formation

Pre-planting soil work involves deep ploughing to 25–30 cm, followed by rotary cultivation or harrowing to produce a fine, level, weed-free seedbed. Soil structure must allow rapid deep drainage — strawberry is extremely sensitive to root asphyxia and to conditions favouring Phytophthora development.

Ridge formation is the reference technique in professional soil-grown production. Ridges 15 to 20 cm high, with 60 to 80 cm between ridge centres, improve drainage, warm the soil more rapidly in spring, and facilitate laying of the plastic mulch film. Immediately before planting, drip irrigation lines are installed under the film — drip is the reference system (efficiency 85 to 95%, investment €1,500 to €3,500/ha in open field).

In organic production, an application of 30 to 40 t/ha of mature compost is recommended 6 months before planting, to allow full incorporation without risk of excess nitrogen at establishment.

Base fertilisation: what is decided before planting

Base fertilisation is inseparable from soil preparation. Macronutrient requirements for a strawberry bed are significant over the duration of the growing cycle and must be planned from establishment.

Reference export figures for a soil-grown strawberry operation are in the order of 60 to 100 kg N/ha/year, 25 to 45 kg P₂O₅/ha/year, and 80 to 140 kg K₂O/ha/year. The recommended base fertilisation formula is oriented towards an NPK ratio of 8-3-10, reflecting the high potassium demand of strawberry — potassium being directly linked to fruit quality, sugar content and firmness.

On calcareous soils (active CaCO₃ > 2%), a chelated iron application is systematically recommended (0.5 to 1 kg Fe/ha/year) to prevent iron chlorosis, which manifests as interveinal yellowing of young leaves and a reduction in yield potential.

Phosphorus (P₂O₅) application is prioritised as a base dressing, before ploughing, to stimulate root development at establishment. Nitrogen and potassium are ideally split over the growing cycle, but a portion of the base dressing (30 to 40% for K₂O) may be incorporated before planting on low-CEC or highly draining soils.

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Planting densities by growing system

Planting density is a parameter that determines both yield potential and disease risk. It varies significantly according to growing system.

System	In-row spacing	Between rows	Density (plants/ha)	Plants/m²
Open field — single row on ridge	25 – 30 cm	80 – 100 cm	33,000 – 50,000	3.3 – 5
Double row on ridge (tunnel / glasshouse)	20 – 25 cm (staggered)	80 – 100 cm between ridges	55,000 – 80,000	5.5 – 8
Soilless elevated gutter	20 – 22 cm	0.8 – 1.0 m between gutters	45,000 – 65,000	4.5 – 6.5

Critical rules at planting

Crown position is decisive. The crown must be flush with the soil surface once the plant has been firmed in and watered. A buried crown causes crown rot and plant death within days; an over-exposed crown leaves the roots exposed to desiccation and compromises establishment. This rule applies equally to cold-stored plants, fresh runners and tray-plants.

Roots must not be bunched or coiled. If roots are too long to be inserted vertically into the planting hole, trim them to approximately 10 cm before planting. Coiled roots create air pockets, slow establishment and favour root infections.

Immediate post-planting irrigation is non-negotiable. A thorough watering in the minutes after planting firms the soil around the roots, eliminates air pockets and initiates the establishment process. Moisture management over the first 15 days is critical: 0.3 to 0.5 L/plant/day, with a target matric tension of 5 to 15 kPa.

Density and Botrytis risk management

Excessive density amplifies the risk of Botrytis cinerea (grey mould), a pathogen that develops optimally under conditions of relative humidity > 75% combined with temperatures of 15 to 20°C. These conditions are structurally present under tunnel at flowering. Planting beyond recommended densities reduces air circulation between plants, increases leaf wetness duration and creates a microclimate favourable to fungal development.

Regular leaf thinning reduces this risk: field evidence indicates a reduction of up to 40% in the proportion of downgraded fruit in seasons where systematic leaf thinning is practised.

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Managing the first weeks after planting

Establishment is confirmed when the plant is in full root recovery — not at the planting date. The first three weeks represent the maximum-risk period.

Water management is the priority. Requirements for the first 15 days are 0.3 to 0.5 L/plant/day, with a target matric tension of 5 to 15 kPa. A water deficit at this stage, even brief, can compromise establishment across entire batches. Tensiometer monitoring is recommended from day one. For details on irrigation management throughout the growing cycle, see Strawberry irrigation: requirements and management.

Remove flower trusses in the first month. Regardless of plant type, removing flower trusses in the 4 weeks following planting is essential to concentrate the plant's energy on root development and vegetative establishment. A plant that fruits too early exhausts its reserves before the root system is sufficiently developed. For growers, this means a short-term sacrifice in yield but an investment in the season's overall potential.

Remove runners throughout the growing cycle. Outside of directed propagation contexts, runners produced by the strawberry plant during the growing season must be removed regularly. Each runner left in place diverts energy from the mother plant into uncontrolled vegetative growth. Runner and leaf management is covered in detail in the article Strawberry plant management: runners and leaf thinning.

Early pest monitoring from establishment. The first weeks after planting represent a window of maximum pest vulnerability. Monitor for slug activity (most active at night, particularly in residual planting moisture), early aphid colonies — notably Chaetosiphon fragaefolii, a virus vector —, and early-stage two-spotted spider mite infestations. Mites can establish discreetly on the undersides of leaves from the first warm, dry days after planting, particularly under tunnels.

Early identification makes a real economic difference. An aphid colony treated at 3 infested plants costs a fraction of the intervention required on a crop at 30% infestation level. Early slug intervention — spreading granules between rows, monitoring humid border zones — prevents losses of young plants whose establishment is already under stress.

From the first weeks, also inspect crowns regularly: blackening at the crown or isolated plant collapse may signal early infection by Phytophthora cactorum or Botrytis cinerea, favoured by excess moisture at planting on poorly drained soil. Detection at first symptom stage still allows isolation of affected plants and correction of the contributing conditions (drainage, ventilation, spacing).

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What planting tables cannot determine for your operation

The data presented in this article — regional windows, system-specific densities, plant types, preparation rules — provides a valid reference framework for professional strawberry growing. It covers the mechanisms and structural variables. It cannot determine the decisions specific to your operation.

The agronomic reality of a strawberry bed is always individual. Your variety has precise cold requirements — has the lot you ordered actually accumulated them? Does the target plot have a high-risk history? Does your Verticillium PCR result allow you to plant this season, or should you delay? Is your irrigation system sized for the establishment requirements of a double-row tunnel planting across an extended area? At what point is it appropriate to remove the first flower trusses on a tray-plant that arrives heavily loaded?

These are operation-specific questions, not questions for a technical guide. They require answers adjusted to your context, available when you need them — not at a scheduled meeting a fortnight later.

Fraisibot, the AI agronomic advisor specialising in strawberry at Agronomia, is designed for exactly this type of decision support. Available 24/7, it answers your technical questions by integrating the specifics of your growing situation. Growers, crop managers and production managers seeking to secure their planting decisions find immediate, constraint-free technical support.

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Conclusion: three structural decisions for a successful planting

Strawberry planting hinges on three levels of decision that interconnect.

The first is plant type selection, inseparable from grade, vernalisation level and production objective. A well-vernalised grade A+ cold-stored plant of a variety suited to your growing region is not interchangeable with a fresh runner of the same variety — they call for different planting dates, different post-planting management, and they produce over different windows.

The second is the backward planning logic from the commercial harvest target. It is the only approach that allows coherent alignment of plant type, planting date and growing system.

The third is soil preparation as a 5-year investment decision: rotation respected, pre-planting analyses completed, soil work thorough. What is neglected before planting cannot be corrected afterwards.

These three levers are documented and quantified. Their application to your specific situation — your plot, your variety, your system — is where standard guidance stops and personalised advice begins.

Fraisibot supports you across the entire strawberry growing pathway, from the planting decision to managing challenges mid-cycle. Ask your questions about your strawberry crop and get answers from your specialist AI agronomic advisor.

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Further reading in the strawberry technical guide: Strawberry plants: cold-stored, fresh or tray-plants? — Soilborne diseases in strawberry — Strawberry agroecology: rotation and mulching