We’re still working out our budget and schedule for this year (obviously – we just got here a couple of weeks ago), and it’s uncertain that we’ll have a greenhouse in time for spring.
Here are some other things we may try (assuming we’re ready for any sort of early season extension ; )
- ID warm microclimates; windbreaks of hedges & trees – plant early crops there.
- Hill up east-west ridges to create rows of south-facing slope. 40 degree slope equals 30% gain in total heat absorption from the soil. We plan on making swales anyway, so this ties in nicely.
- Two parallel lengths of snow or dune fencing 4 ft high and 60 ft apart can raise air temp 1-4 degrees
- Snow/dune fence + hedge = increase of 5 degrees air temp
- Windbreak fabric, set perpendicular to prevailing winds
- 2-3 ft high temporary translucent fabric between rows – raises daytime temp 10 degrees (basically like a greenhouse minus the roof = ventilation and irrigation are done by nature)
- Darken soil (with charcoal, etc)
- Plastic mulch (black polyethylene retains moisture, warms the soil, blocks weeds). You can also get biodegradable kinds, like they have at Stone Barns. Perforated kinds let water pass through into the soil. Clear plastic warms even more (like mini greenhouse), but it doesn’t shade weeds.
- Slitted row covers or floating row covers
- Walk-in Tunnels
Thanks again to Eliot Coleman for the specific numbers about degrees…