Planning polyhouse farming in Rosera? Rosera is a small town in Samastipur district, Bihar, home to about 31,000 people (GeoNames)[1][2], about 430 km from Kolkata. Below we use the town's monthly temperatures, humidity and rainfall to work out which structure fits, which crops to grow and in which months, before you spend on construction.
Climate for polyhouse farming in Rosera
May is the hottest month in Rosera, with average daily highs of about 40°C. January has the coolest nights, averaging 8°C.[3] The area gets about 1,069 mm of rain a year, most of it in June to September, peaking in July at about 294 mm. Average humidity stays at 75% or more in July to October, which raises the risk of leaf disease and slows evaporative cooling. On the Köppen–Geiger climate map, Rosera falls in the humid subtropical with dry winters zone (Cwa).[4]
Rosera climate by month
Month
Avg high (°C)
Avg low (°C)
Humidity (%)
Rain (mm)
Jan
23.2
8.2
51
8
Feb
28.1
11.9
43
12
Mar
34.6
17.6
31
15
Apr
39.3
23.4
31
27
May
40.1
26.8
42
73
Jun
38.3
28.2
57
169
Jul
33.3
26.5
80
294
Aug
32.4
26.0
84
213
Sep
31.4
24.6
84
201
Oct
30.5
20.6
75
53
Nov
27.8
14.8
64
2
Dec
23.9
9.8
58
2
Area averages (a grid cell of about 50 km) for 2001–2025, from NASA POWER, centred on Rosera. Rainfall and night temperatures at your plot can differ, especially near hills and the coast.[3]
Advantages of protected cultivation in Rosera
1
Year-round crops
A polyhouse stretches the season: in Rosera cucumber can be grown for about 9 months a year under cover, longer than in the open field.
2
Better yield and price
Plants grow without rain, hail and wind damage, so yields are higher and more even, and clean, graded produce sells at a better price, especially off-season.
3
Less water
Drip irrigation under cover uses less water than flood irrigation, and the roof keeps July's 294 mm of rain off the crop and the soil.
4
Less pesticides
Insect net on vents and doors keeps out most pests, and controlled ventilation helps with leaf disease in the humid months (July to October), so you spray less often.
5
Subsidy eligible
Polyhouse, shade net and nethouse projects in Bihar can apply for Mission for Integrated Development of Horticulture (MIDH) assistance through the state horticulture department.[5]
Which polyhouse suits Rosera?
For polyhouse farming in Rosera, the structure decides which months you can crop and what it costs to run. The heat in Rosera comes with dry air. In April to June, average highs reach 40°C while average humidity is only about 43%. In that dry air, wet pads can bring a 40°C May afternoon down to roughly 32°C inside a Fan & Pad polyhouse, which keeps herbs and vine crops going; lettuce will still struggle in the hottest weeks. For vine crops such as capsicum and cucumber, a naturally ventilated polyhouse with a shade screen works from February and October to November and costs less to run.
Plan for heavy rain in July (about 294 mm): raise the plinth, size the gutters for that month and keep drains away from the nutrient tank. A nethouse, the lowest-cost option, can grow hardy crops in February and October to November, when it is mild and fairly dry.
Crops for Rosera
Based on Rosera's climate, the crops with the longest growing windows are cucumber (9 months), chilli pepper (9 months) and capsicum (8 months). Cucumber fits March to November with Fan & Pad cooling. These are the crops we would plan first for polyhouse farming in Rosera.
Months each crop suits in Rosera
Crop
Naturally ventilated polyhouse
With Fan & Pad cooling
Capsicum
Feb and Oct–Nov
Feb–Apr and Jul–Nov
Tomato
Feb and Oct–Dec
Feb–Apr and Sep–Dec
Cucumber
Jul–Nov
Mar–Nov
Chilli pepper
Feb and Aug–Nov
Feb–May and Jul–Nov
Brinjal
Aug–Nov
Mar–May and Jul–Nov
Lettuce
Nov–Jan
Oct–Apr
Broccoli
Dec–Jan
Nov–Feb
Strawberry
Dec–Jan
Nov–Feb
Rose
Nov–Dec
Feb–Mar and Oct–Dec
Gerbera
Nov–Dec
Feb–Apr and Oct–Dec
Carnation
Dec–Jan
Nov–Feb
Chrysanthemum
Nov–Dec
Feb–Mar and Oct–Dec
Anthurium
Difficult
Mar–May and Jul–Oct
Orchids
Difficult
Mar–May and Jul–Oct
Lilium
Dec–Jan
Nov–Feb
Kryzen planning estimate from the monthly averages above and each crop's usual day and night temperature range. Variety, soil or substrate temperature and shading change the result, so confirm with a trial.
₹5,165Spending per person per month, urban Bihar, 2023–24[6]
430 kmto Kolkata, the nearest metro (straight line)
Urban households in Bihar spent an average of ₹5,165 per person per month in 2023–24, below the all-India urban average of ₹7,078.[6] Local demand in Rosera may be small for exotic greens, so plan where the rest of the harvest goes. Begusarai, about 40 km away, is the nearest larger market on our list.
Polyhouse farming in Rosera with Kryzen
We have built 2 projects in Bihar so far (see our project map (opens in a new tab)). Rosera is about 1,270 km in a straight line from our Chhatrapati Sambhajinagar warehouse, our nearest site.
Towns near Rosera
We also plan and build farms in these towns near Rosera:
Map: LGD 2024 boundaries via bharatlas, CC BY 4.0. For illustration only.
Polyhouse farming in Rosera: FAQs
Can a polyhouse farm run all year in Rosera?
Yes, with the right structure. For Rosera we would plan a Fan & Pad polyhouse for leafy greens. Even then, lettuce is hard to grow in May to September, so plan another crop for those months.
Which polyhouse is best for Rosera?
With May highs of about 40°C and 42% average humidity in that month, we would start with a Fan & Pad polyhouse for leafy greens.
Which crops should I grow in a polyhouse in Rosera?
Going by the monthly climate, cucumber, chilli pepper and capsicum have the longest growing windows. Confirm prices and volumes with buyers before you plant.
Is polyhouse farming profitable in Rosera?
It can be, if the crop, the structure and the buyers match. In Rosera, cucumber and chilli pepper have the longest seasons under cover. Confirm prices and volumes with buyers first; our Detailed Project Report works out the cost, yield and returns for your plot.
Does Kryzen build polyhouses in Rosera?
Yes. Our nearest site is our Chhatrapati Sambhajinagar warehouse, about 1,270 km away, and we have built 2 projects in Bihar.
Is there a subsidy for polyhouse or hydroponic farms in Bihar?
Yes. Protected cultivation projects in Bihar can apply for Mission for Integrated Development of Horticulture (MIDH) assistance through the state horticulture department. Check the current rate and area limit when you apply.
Discuss your Rosera farm project
Share your plot location, water test and crop targets. We will suggest the right structure and growing system, and send an itemised quotation.
A computer engineer turned hydroponic farmer from a multigenerational farming family in Satara. Sudhir founded Kryzen in 2019, and the team has since built 350+ protected and hydroponic farms across India.
