Extending the Growing Season in Rhode Island - Workshop Resources

8/9/2019 Extending the Growing Season in Rhode Island - Workshop Resources

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Extending the Growing Season WorkshopSeptember 19th, 2012

1. Growing Season in Rhode Island

• 2012 season, the average number of frost-free days was 147

(Kingston, RI).• Growing season from May 8

th to October 3.

• Plant Hardiness Zones are geographically identified areas thatshow a 10 degree difference between zones. These zones indicatewhat plants will fair well in those locations.

• The majority of Rhode Island is found in plant hardiness zone 6(average annual low of 0° to -10°), with only Block Island and theSouthern Coast and the east bay in zone 7 (average annual low of10° through 0°). Some maps show the North West corner of RI as5b.

• Average depth of frost penetration is between 25-30 inches.

• 120 average mean annual number of days with a minimum temp of32° and below

• Plant growth slows the most when day length drops below 10 hours,from early November to Early February

• Slow down of plant growth is not just light related, its alsotemperature and wind related as well.


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2. How do you want to extend the growing season?

• Do you want to grow crops to be harvested and eaten in thefall/winter?

•

Do you want to grow crops that will be ready to harvest in thespring (overwinter)? Lettuces, spinach, onions

• Location, Planning and Choosing the right Plants.

• Creating Protected Microclimates- the climate of a small area that isdifferent within the greater area that surrounds it. Create amicroclimate suitable for what types of plants you want to grow.Changing the microclimate can be as simple as planting yourgarden on a south facing slope where there will be the most sunexposure, planting in an area that is surrounded by a stone wallthat will trap heat, thus making the soil and the surrounding air

warmer, or planting near a hedgerow or row of shrubs to protectplants from the cold winter winds.

• The simplest way to harvest through the first few frosts is to plan ona late planting including frost-hardy plants. Plant crops that haveharvest dates of 30, 60 and 90 days, and add a few days toaccount for the fact that the plants may slow down as the weatherbecomes cooler. Mulch around the plants to add a few degrees of


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extra warmth to their roots. Growing in raised beds also helpsincrease the soil temperature.

3. Plants

• Choosing Plants for winter hardiness, including salad greens and

root vegetables- thrive in cold.• Typical growing methods for extending the growing season

• Soil quality is important. Test and amend accordingly, especially ifyou are using the same plots over and over. Till in peat moss (withlime to reduce acidity) to improve structure and to make sureenough moisture. Thermal decay of highly organic soil= warmplants.

4. Methods of Extending the Growing Season*make sure whatever you use is in a location that won’t be shaded when thesun is lower in the sky in the winter. Max out the sun.

*anti-drip coating on plastic- condensation in films not droplets- lets in morelight and film reflects waves from soil keeping it warmer at night*Ventilate when temperature under the inner cover is 70 degrees, and byMarch 15th, daily- too warm can be more damaging than too cold*little supplemental moisture is needed in winter bc of the low evaporation &high water tables*Hay is also a good insulator around rows/raised beds/cold frames

• Row Cover- spun-bonded fabric. Heavy ag fabric, while protectingplants from the elements, only allows 50% sunlight, so it’s better togo lightweight.

• Mulch- insulation, discourages weeds, prevents soil erosion- becareful what you use- nitrogen leaches with sawdust and barkmulch. 1-2 inches good

• Raised Beds- 8-12 degrees warmer if well managed.

• Glass/Plastic Cloches

• Cold Frames- grow at summer speed through November, thensemi-hybernate. equivalent of moving plants 1 ½ USDA zoneswarmer, angle so there is a better angle for light/rain and snowrunoff.

• Low Tunnels/Hoop Houses- align on east-west axis, UV resistantplastic, Elliot Coleman- 10ft lengths of electrical conduit, plastic or

metal, every 5 feet, covered with spun-bonded fabric held downwith sandbags at hoops. In Nov/Dec add 10 foot wide plastic overrow cover for snow protection- make sure you fully secure. Inplaces w heavy snow, hoops 2 ½ feet apart.

• High Tunnels- unheated & non-mechanically ventilated. unheatedis 6-7 degrees warmer

• Row Cover/Tunnel Combo- 12 inches above soil, equivalent ofmoving plants 3 USDA zones warmer, row covers are easy to


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manage in high tunnels supported by flat-topped wire wickets andheld by clothes pins.

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Extending the Growing Season in Rhode Island - Workshop Resources