Growing Raspberries in a Greenhouse: The Complete Beginner's Guide!

There's something a little magical about biting into a freshly picked, still-warm raspberry in the middle of November. Not from a supermarket. Not imported from Spain. From your own garden, in your own greenhouse. This is exactly what a well-equipped polycarbonate greenhouse makes possible, and it's precisely what we're going to explain in this guide.

Growing raspberries in a greenhouse isn't just for professional market gardeners. With a bit of method, the right advice, and the right structure, any amateur gardener can do it. And believe us: once you've tasted homegrown raspberries, there's no going back. 🌱

At AtmoSerre, we support hundreds of passionate gardeners every year. This guide is the fruit of that accumulated field experience over the seasons. Get comfortable, take notes, and let's discover together how to transform your greenhouse into a true raspberry paradise. ✨

Why Grow Raspberries in a Polycarbonate Greenhouse? 🤔💡

Good question. Raspberries are a fruit that, outdoors, can be finicky. They dislike extremes: too much heat, too much stagnant humidity, early frost in autumn, late frosts in May... The list of raspberry enemies is long. And that's where the polycarbonate greenhouse comes in.

Unlike a glass greenhouse (which heats up excessively and creates shaded areas), or a simple plastic tunnel greenhouse (which rarely lasts more than two or three seasons), multi-wall polycarbonate offers something unique: homogeneous light diffusion, remarkable thermal insulation, and impact resistance that truly reassures when you've invested time in your crops.

Here's what growing in a polycarbonate greenhouse concretely changes for your raspberries:

• 🌡️ Stabilized temperatures: no sudden frost, no heatstroke. Raspberries love this.
• 💧 Controlled humidity: you water when you want, how you want, without depending on rain or fickle sun.
• 🐛 Fewer pests: harmful insects have a much harder time reaching your plants.
• 📅 Extended season: you harvest from June to November, or even later depending on your region and greenhouse model.
• 🍓 Superior fruit quality: larger, sweeter raspberries, less damaged by bad weather.

And the often underestimated advantage? Peace of mind. When the weather forecast announces three days of rain, you know your raspberries won't flinch. 😌

Which Raspberry Variety to Choose for Greenhouse Cultivation? 🍓🌱

Even before talking about soil or watering, you need to choose the right variety. And there, not everyone will tell you the same thing. After observing dozens of crops in polycarbonate greenhouses, here's what we can tell you with certainty.

Ever-bearing varieties: the best choice for the greenhouse 🏆

Ever-bearing raspberry canes produce twice a year: a first harvest in summer on the previous year's canes, then a second harvest in autumn on the new canes. In a greenhouse, this second autumn harvest is particularly interesting, as you can extend it well past the first outdoor frosts.

Some ever-bearing varieties that work really well in a greenhouse:

• 🍓 Polka: very productive, firm and sweet fruit, good disease resistance. Our favorite for beginners.
• 🍓 Autumn Bliss: abundant harvest from late August, large fruit, pronounced flavor.
• 🍓 Erika: less known but excellent in a greenhouse, it produces late which is perfect for optimizing space under polycarbonate.
• 🍓 Heritage: a reliable choice, very hardy, it tolerates even slight temperature variations well.

Summer-fruiting varieties: best for larger greenhouses 🌿

Summer-fruiting varieties like Malling Promise or Glen Ample produce only once in summer on the previous year's canes. They are less interesting in small greenhouses, as they occupy space all year for a single harvest. In a more spacious greenhouse, however, they can produce exceptional fruit. It all depends on your space and your goals.

Our clear recommendation for starting out in a polycarbonate greenhouse: opt for an ever-bearing variety, especially Polka or Autumn Bliss. You won't be disappointed. 🙌

Which Polycarbonate Greenhouse to Choose for Growing Raspberries? 🏡🛠️

This is a question many beginners overlook, and yet it is fundamental. Not all raspberry plants require the same space, and depending on the size of your collection and your gardening ambitions, you won't need the same greenhouse.

Headroom in the greenhouse: an often forgotten criterion 📏

Raspberry canes, depending on the variety, can reach 1.50 m to 2 m in height. Your greenhouse must therefore be high enough to accommodate the canes vertically without bending them. A greenhouse that is too low = bent canes = disturbed sap circulation = fewer fruits. It's as simple as that.

The minimum recommended height is 2 m at the ridge, ideally 2.20 m to 2.40 m for comfortable cultivation without having to bend over every time you water. 😅

Surface area: how many raspberry plants can you put in a greenhouse?

As a general rule, raspberry plants are planted in rows spaced 80 cm to 1 m apart, with 40 to 50 cm between each plant in the row. For a 6 m² greenhouse, you can reasonably cultivate 8 to 12 plants. For a 12 m² greenhouse, this increases to 20 to 25 plants, which is already a good yield.

4mm or 6mm polycarbonate for raspberries? 🤔

• 4mm: suitable for regions with mild or moderate climates (South-West, Atlantic coast, Provence...). It allows more light to pass through, which can be an advantage for varieties that require a lot of sun.
• 6mm: recommended for colder regions (North, East, Massif Central, Alps...). It insulates better, provides more protection against nocturnal frosts, and extends the harvesting season by several weeks.

If you live in an area with harsh winters, 6mm polycarbonate is clearly the right choice for your raspberries. It's better to invest correctly once than to lose an entire harvest due to a night that's too cold in October. 🥶

A model that is perfectly suited for growing raspberries is L'Intemporelle from AtmoSerre. Available from 6 m² to 36 m², in 4mm or 6mm, it offers generous interior volume, excellent light diffusion thanks to its tunnel shape, and truly reassuring resistance to bad weather (up to 180 km/h wind and 90 cm of snow). Exactly what you need to grow raspberries serenely, season after season. 🌱

If you wish to explore all available models, you can consult our complete collection of garden greenhouses to compare dimensions and features according to your project.

Preparing the Soil in Your Polycarbonate Greenhouse for Raspberries 🌍🪴

Raspberries are demanding about soil quality. Not capricious, but demanding. There's a nuance. They need well-drained soil, rich in humus, slightly acidic (pH between 5.5 and 6.5) and at least 40 cm deep for the roots to thrive.

Common mistakes to avoid 🚫

• ❌ Compact or clayey soil without amendment: roots suffocate, the plant languishes and produces almost nothing.
• ❌ Soil too calcareous (pH > 7): raspberries suffer from chlorosis, leaves turn yellow, production drops drastically.
• ❌ Permanently overly wet soil: promotes root diseases, especially Phytophthora, a devastating fungus.
• ❌ Replanting raspberries where they already were: the soil "tires" and diseases accumulate. Change location or completely renew the soil.

How to prepare good soil for raspberries in a greenhouse? ✅

1. Decompact the soil 40 to 50 cm deep using a broadfork or a digging fork. Do not turn the soil, just aerate it. This preserves the microbial life of the soil. 🐛
2. Incorporate mature compost: 5 to 10 kg per m². Good homemade compost is better than any chemical fertilizer.
3. Add basalt powder (optional but very effective): it remineralizes the soil and improves its structure in the long term.
4. Check the pH with a simple tester (available in garden centers for less than €10). If your soil is too alkaline, incorporate agricultural sulfur or conifer potting mix to acidify it slightly.
5. Install a thick mulch (10 to 15 cm of wood chips, straw, or ramial chipped wood) after planting. It retains moisture, regulates soil temperature, and limits weeds. 🌿

Well-prepared soil is 70% of the work done. Everything else is just maintenance. 💪

Planting Raspberries in a Greenhouse: When and How? 🌱📅

When to plant?

In a polycarbonate greenhouse, you have much more flexibility than outdoors. But there are still preferred periods:

• 🍂 October to November: autumn planting allows the roots to settle quietly during the calm months, and the plant grows vigorously in spring.
• 🌸 March to April: spring planting also works very well, especially with potted plants (for bare-root, autumn is preferred).
• ☃️ Avoid December-February if your greenhouse is not heated: the soil is too cold for good establishment.

How to plant correctly? 🛠️

Dig a hole approximately 30 cm deep and 30 cm wide. Place the plant in the center, ensuring that the collar (the junction between the roots and the stem) is at ground level, not buried. This is a very common mistake among beginners who think that burying deeper provides more stability. This is false, and it promotes rot. 🚫

After planting:

• Lightly tamp the soil around the plant
• Water abundantly (even in autumn)
• Install your mulch
• Set up your supports (stakes or wires stretched along a fence or posts) 📏

The raspberry plant climbs and spreads if not managed. In a greenhouse, space is precious. From the start, consider installing a trellis with two or three wires stretched horizontally at 50 cm, 1 m, and 1.50 m in height. This truly makes a difference in managing the canes. ✅

Watering Raspberries in a Greenhouse: Not Too Much, Not Too Little 💧

This is the point where many beginner gardeners struggle. Raspberries need regular but not excessive water. And in a greenhouse, without natural rain to modulate the intake, you manage everything. Which is freedom... but also responsibility.

Signs of improper watering

• 🍂 Leaves turning yellow and falling quickly: too much water, roots are suffocating.
• 🥀 Leaves curling and browning at the edges: lack of water, especially during hot periods.
• 🍓 Small and less sweet fruits: insufficient watering during fruit development (June-July-August).
• 💦 Fruits cracking or rotting quickly on the plant: excessive water just before harvest.

How often should I water?

During active growth (March to September):

• In hot weather (above 25°C in the greenhouse): water generously every 2 days at the base of the plants. Avoid wetting the leaves, especially in the evening. 🌡️
• In cool weather (below 20°C): every 4 to 5 days is plenty.
• In winter: drastically reduce watering. Watering every 10 to 15 days is often sufficient if the greenhouse is closed.

💡 Our field tip: Install a drip irrigation system directly at the base of the plants. This is the best investment you'll make for your greenhouse. Water goes directly to the roots, without contact with the leaves, which greatly limits fungal diseases like botrytis. And you can easily save 40-50% of water compared to traditional watering. 💧

Fertilization and Nutrition: Smart Raspberry Feeding 🌿🧑🌾

Raspberry plants are heavy nutrient consumers, especially during flowering and fruit development. In a greenhouse, the soil is not naturally replenished by rainwater or external organic matter. Therefore, regular but judicious feeding is necessary.

Simplified fertilization schedule

💡 What we often see in the field: beginners over-fertilize with nitrogen at the wrong time (often in June-July). The result: the plant grows too fast vegetatively, produces fewer fruits, and becomes more vulnerable to aphids that love soft, nitrogen-rich shoots. Less fertilization in summer = paradoxically more fruit. 🙃

Pruning Raspberries in a Greenhouse: Essential and Simple! ✂️🌿

Pruning is one of the most important techniques for obtaining a regular and abundant production. And yet, it's often the one that beginners fear the most. The good news is that raspberry pruning, once you understand the logic, is really simple.

Understanding how canes work 🌱

Raspberry plants produce canes (stems) that have a two-year life cycle:

• First-year canes (called primocanes): they grow during the summer, do not produce fruit in the first year (except for fall-bearing varieties), and overwinter dormant.
• Second-year canes (called floricanes): these are the primocanes from the previous year. They flower and produce fruit in spring-summer, then die naturally after harvest.

When and how to prune?

For everbearing varieties (which we recommend for the greenhouse):

• In late autumn or early winter (November-December): cut all canes that have produced fruit at ground level. These are the floricanes. They are exhausted, useless, and clutter the greenhouse.
• Keep only the young canes of the current year, which will produce next year. ✅
• Shorten them slightly if they exceed 1.50 m to 1.80 m, so they stay under the roof of your greenhouse.

To simplify even further ("single cut" method): some gardeners cut all canes in November, flush with the ground. The plant restarts entirely from scratch in spring. You lose the summer harvest of the following year, but you get one large autumn harvest, which is very easy to manage. This method is perfect for beginners who don't want to overthink it. 🙌

Ventilation and Temperature in the Greenhouse: The Perfect Balance 🌡️💨

Growing raspberries in a polycarbonate greenhouse also means managing heat and humidity. And this is a point many neglect at first, sometimes with serious consequences for crops.

What are the ideal temperatures for raspberries in a greenhouse?

• 🌸 Flowering: 15°C to 20°C. Below this, bees pollinate poorly. Above 25°C, flowers may abort.
• 🍓 Fruit development: 18°C to 24°C, with cool nights (ideally 12°C to 15°C). This day/night temperature range promotes sugar and aroma synthesis.
• 🌿 Vegetation: up to 28°C during the day, as long as ventilation is good.
• ❄️ Winter: raspberry plants tolerate negative temperatures (down to -10°C approximately), but a closed greenhouse generally keeps the soil above 0°C, which is perfect for dormancy.

Proper ventilation: a must, not an option 💨

In mid-summer, the inside of a greenhouse can reach 45°C to 50°C if it's closed. This is deadly for raspberries. It is absolutely essential to plan for:

• ✅ Roof vents (in the roof) to allow heat to rise naturally.
• ✅ Low openings (doors or side windows) to create an upward airflow.
• ✅ Open as soon as the temperature exceeds 25°C in the greenhouse.

L'Intemporelle is equipped with integrated openings that truly simplify this management. It's a detail that seems minor but makes a real difference day-to-day. 🌬️

To delve deeper into this topic, our article Growing Strawberries in a Greenhouse All Year Round also discusses thermal management strategies in polycarbonate greenhouses, with very practical advice applicable to your raspberries.

Raspberry Diseases and Pests in a Greenhouse: Prevention Rather Than Cure 🐛🍄

A polycarbonate greenhouse significantly reduces the risk of diseases and pests compared to outdoor cultivation. But it doesn't eliminate all risks. Here's what you need to watch out for.

Main diseases to watch out for 🍄

Botrytis (gray mold): This is the main enemy of raspberries in a greenhouse. It thrives in humid and warm weather and can destroy an entire crop in a few days. The fruits turn brown and become covered with a characteristic gray mold. Prevention: ventilate well, avoid wetting the leaves, and remove damaged fruits from the plant. 🍂

Anthracnose: Circular brown spots appear on the canes. It develops in humid conditions. Avoid planting too close together and ensure good air circulation between plants.

Rust: Orange pustules on the underside of leaves. Rare in a well-ventilated greenhouse, but possible. Remove affected leaves immediately.

Main pests 🐛

• 🐞 Aphids: They settle on young shoots in spring. Introducing ladybugs into the greenhouse (yes, really!) is the most effective and satisfying solution. Alternatively, diluted black soap applied with a sprayer works well.
• 🕷️ Spider mites (red spiders): In hot and dry conditions. Maintaining some humidity in the greenhouse naturally deters them.
• 🐝 Thrips: They leave silvery traces on the leaves. Use yellow and blue sticky traps in the greenhouse to monitor and capture them.

The golden rule in a greenhouse: observe regularly. No need to spend hours. Five minutes twice a week inspecting the leaves (undersides included), stems, and fruits, and you'll detect 90% of problems before they become uncontrollable. 🧐

Raspberry Pollination in a Greenhouse: An Often Overlooked Point 🐝🌸

Outdoors, bees and pollinating insects do the work naturally. In a greenhouse, it's different. Depending on your setup, insects may or may not enter easily, and if the vents are closed in cool weather during flowering, your flowers may not be pollinated.

How to ensure good pollination?

Option 1: Leave the vents and door ajar during the day while flowering (April-May generally). Wild bees and bumblebees easily enter and do an excellent job. This is the simplest and most natural solution. 🐝

Option 2: Manual pollination. Yes, it might seem tedious, but for a small greenhouse, it takes 5 minutes and is very effective. Use a fine brush or even a simple cotton swab, and gently move from flower to flower, collecting and depositing pollen. Do this in the morning, when the flowers are wide open. 🌸

Option 3: Install a beehive or insect hotel near your greenhouse. Wild insects (mason bees, bumblebees) are even more effective than domestic bees for raspberry pollination. And an insect hotel is a modest investment that will benefit your entire garden. 🪲

According to data from INRAE (National Research Institute for Agriculture, Food and Environment), poor pollination can reduce raspberry yields by 30 to 50%. This is huge, and yet it's a factor that very few guides mention seriously.

Harvesting and Storing Raspberries: How to Get the Most Out of Your Fruit? 🍓✨

After all that work, here comes the most rewarding moment: the harvest! 🎉

When to harvest?

Raspberries are harvested when they detach easily from the receptacle (the small white cone that remains on the plant). If you have to pull to detach it, it's not yet ripe. If it falls off by itself, you've waited a little too long.

Color alone is not enough of an indicator: some varieties are bright red when fully ripe, while others have a darker hue. Rely mainly on the ease of detachment and the aroma (a ripe raspberry smells strong and good 😍).

Harvest preferably in the morning, when the heat is not yet at its peak. The fruits are firmer, easier to handle, and they keep much better. ☀️

How to store your raspberries?

• 🍓 At room temperature: maximum 24 hours. Raspberries are extremely delicate fruits.
• ❄️ In the refrigerator: 2 to 3 days, without washing them (water accelerates spoilage).
• 🧊 In the freezer: the best option for large harvests. Freeze in a single layer on a tray, then transfer to a bag. You'll get perfect individual raspberries for smoothies, jams, or desserts all winter long.

Optimizing Greenhouse Space for Maximum Production 📈🪴

A greenhouse, especially if it's modest in size, deserves intelligent planning. Raspberry bushes shouldn't take up all the space if other crops can coexist with them.

What plants to associate with raspberries in a greenhouse? 🌿

• 🧄 Garlic: an excellent companion. It naturally repels several raspberry pests.
• 🌼 Borage: its flowers attract pollinators and repel certain harmful insects.
• 🥬 Lettuces: they grow quickly and occupy the ground space under the raspberry bushes without significant root competition.
• 🌿 Chives: planted at the edge of rows, they naturally repel aphids.

What we advise against: planting tomatoes next to raspberry bushes in a small greenhouse. These two plants sometimes share the same fungal diseases, and tomatoes can take up a lot of space and light. In a large greenhouse, association is possible with good row separation. 🚫🍅

Using vertical space is also very effective in a greenhouse. Shelves or raised beds above the raspberry level allow you to grow herbs, lettuces, or seedlings without encroaching on the fruit space. 🌱

To further maximize your space, visit AtmoSerre to discover our accessories specifically designed to optimize growing space in a greenhouse.

Growing Raspberries in a Greenhouse All Year Round: Is It Really Possible? 📅🍓

The honest answer: almost. With a polycarbonate greenhouse and everbearing varieties, you can harvest raspberries from June to November without any difficulty. To extend harvesting until December or January, you'll need either supplementary heating or to live in a very mild region.

Raspberry plants need a dormancy period in winter, ideally 6 to 8 weeks at cool temperatures (between 0°C and 7°C). It's this relative cold that "programs" the plant for good production the following year. A greenhouse continuously heated to 20°C all winter will not yield good long-term results.

In practice, the optimal cycle in a polycarbonate greenhouse looks like this:

• 🌱 January-February: rest, light pruning for cleaning
• 🌸 March-April: vegetative restart, first flowers for everbearing varieties
• 🍓 June-July: first harvest
• 🌿 August: growth of new canes
• 🍓 September-November: second harvest (the best in a polycarbonate greenhouse!)
• ❄️ December: entering dormancy

It's this extended harvest calendar of almost 6 months that makes greenhouse cultivation so appealing compared to outdoor growing. 😍

FAQ: Your Questions about Growing Raspberries in a Greenhouse 🙋

Is growing raspberries in a polycarbonate greenhouse difficult for a beginner?

No, not at all! Raspberry is a robust and forgiving plant, as the English say. It forgives many mistakes. With the basics presented in this guide (good soil, regular watering, winter pruning, proper ventilation), even a beginner gardener can achieve very good harvests from the first or second year.

How long until the first harvests in a greenhouse?

For a plant purchased in pots in spring, expect a small autumn harvest the same year (everbearing varieties), and truly significant production from the second year. Bare-root plants planted in autumn start slower but often perform better over time. 🌱

Do you need to heat your greenhouse to grow raspberries?

No, it's unnecessary and even counterproductive in the long run. Raspberry plants need a cool winter to recharge their batteries, so to speak. An unheated polycarbonate greenhouse keeps the soil frost-free in most French regions, which is largely sufficient. 🌡️

Can raspberry plants be grown in raised beds or pots in a greenhouse?

Yes, but with containers of at least 50 to 60 liters per plant. Raspberry plants have an extensive root system and need volume to develop well. Pots that are too small = cramped roots = very limited production. Use well-draining potting mix, enriched with compost. 🪴

What is the difference between 4 mm and 6 mm polycarbonate for raspberries?

For areas with mild winters, 4 mm is sufficient. For areas with regular frosts or long winters, 6 mm offers better thermal insulation and extends your autumn harvest season by several weeks. Our article How to Start Seeds in a Greenhouse: The Complete Beginner's Guide also addresses this topic in detail in the context of early seedlings.

What greenhouse area is needed to grow raspberries seriously?

For family use (4 to 6 people), a 12 m² greenhouse is a good starting point. It will allow you to plant 20 to 25 plants, enough for regular harvests for fresh consumption and freezing. To produce more or combine other crops, opt for 18 m² or more.

Conclusion: Growing Raspberries in a Greenhouse, a Winning Bet 🍓🏆

There you have it. You now know the essentials for starting raspberry cultivation in a polycarbonate greenhouse, from variety selection to harvest management. It's not complicated, really. It's mostly a matter of observation, regularity, and common sense.

The polycarbonate greenhouse is the ideal tool for this crop: it protects, it insulates, it diffuses light correctly, and it adapts to all garden configurations. Whether you have 6 m² or 36 m² available, there is bound to be a model that suits your project.

If you're new to greenhouse gardening and are still hesitant about which model to choose, discover the AtmoSerre universe and let us guide you. Our greenhouses are designed by enthusiasts, for enthusiasts. Every detail matters, and this philosophy is reflected in every harvest. 🌱

Happy growing, and see you soon for a well-deserved beautiful raspberry harvest! 🍓✨