With a long wet season and a pretty hot summer, its often tempting to grow vegetables in a more insulated/protective environment – ergo a green house. But growing in such an environment is different enough from our usual organic approaches while growing in the field to give us some pause.
For example, while its probably easier to prevent insects and other fungal/bacterial diseases from getting to your crops, other beneficial ones probably get eliminated too. Also, maintaining good air circulation within the greenhouse can present an interesting challenge in our climates. Also, there is the cost of the green-house to consider, along with the fact that it needs to fit our needs in two very different seasons – summer and monsoon.
From our visits to a few organic green-house projects (in Pune and Coimbatore), we’ve been able to observe the following:
- Indian greenhouses seem to be plastic+shadenet combo structures which shelter plants considerably from wet and hot weather
- They are very carefully insulated from any external pests, with care taken while entering and leaving the interior
- Most growers seem to have little use for the sprinklers and have adopted drip-irrigation for their watering needs
- Timely and regular sprays of neem and other preventive organic pest repellents seem critical to a pest-free environment
- Strangely (for us), there is less emphasis on crop diversity than we practice on our fields
- Certain vegetable varieties seem to be better suited to greenhouses (not sure how)
- Providing nutrition through the drip system seems to work well for greenhouse growers