Growing Vegetables in Winter Using Protected Structures · Growing Vegetables in Winter Using Protected Structures. Ohio Ecological Food and Farming Association. Dayton, Ohio. Presented

Growing Vegetables in Winter Using Protected Structures

Ohio Ecological Food and Farming AssociationDayton, OhioFeb. 16, 2018Presented by:

Michael O’Donnell, Purdue ExtensionDavid Robb, Eden Prairie FarmLiz Maynard, Purdue Dept. of Horticulture and LA

Facebook @PurdueSmallFarms

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Fall and Winter Vegetable Production in Protected Structures• “Winter: The Hottest Thing in

Farming” New technology—and growing demand for local food—is making winter farming more possible than everhttp://civileats.com/2017/01/03/winter-the-hottest-thing-in-farming/

• Production of cool season / cold hardy crops in low tunnels, unheated (cold) and minimally-heated (cool) high tunnels, with strategic use of row covers.

• Not covering basics of high tunnel construction/selection/etc. 2

Hi-techhydroponic tomatoes

http://www.npr.org/sections/thesalt/2016/06/16/473526920/how-canada-became-a-greenhouse-superpower

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Fall and Winter Vegetable Production in Protected Structures• Great way to diversify use of existing structures.

• Increase income and maintain relationship with customers for four seasons.

• Increasing number of winter farmers markets.

• Greater income potential per sq ft with cool season crops? Do you have markets?

• More researchers and practitioners, so production systems maturing, lots of information available.

• Value proposition for local leafy greens versus product off the truck.5

Fall and Winter Vegetable Production in Protected Structures• Questions remain: timing, varieties, yield potential, financial benchmarks

• Each farm microclimate is unique. Monitor and keep records.

• Potential impact to planning time and quality of life factors.

• Balancing warm- and cool-season crops in valuable “real-estate.”

• High tunnel features impact level of daily management.

• Other infrastructure considerations are necessary,E.g., irrigation, heated wash-pack facility, product storage, ventilation that limits crop exposure to winds, access to crops (doors that don’t freeze shut), etc.

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Clay Bottom Farm – The “Lean Farm”

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River Ridge 10/19

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River Ridge 11/10

Clay Bottom 12/2

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River Ridge 12/12

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River Ridge 12/20-26

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Who Are You?

Do you produce vegetables for sale?Do you grow in high tunnels? Do you grow in high tunnels in the winter?

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Clay Bottom Farm, GoshenTwo high tunnels in the project:Unheated: 90X30X14, single layer polyHeated: 90X30X14, double layer poly, 28F

Partner Farms

River Ridge Farms, RoannTwo high and one low tunnel in the project:Unheated: 96X30X12, double layer polyHeated: 96X30X12, double layer poly, 32FLow tunnel: 30X6X3, row cover with plastic added in very cold weather.

Eden Prairie Farm, GreenfieldOne high and one low tunnel in the project:Unheated, ‘caterpillar’ tunnel: 50X12X7, single layer polyLow tunnel: 50X4X4, row cover

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Partner Farms

EDEN PRAIRIE

CLAY BOTTOM

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Mean Temp

RIVER RIDGE

Solar RadIation and DLI

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Partner Farms

Collaborators: James Farmer, Project PI, and Analena Bruce, Project Post Doc, Indiana University Bloomington, E. Maynard, co-PI and E. Blrhm, Technician, PurdueAcknowledgements:Pinney Purdue Ag Center Staff: J. Leuck, M. O’Neal, A. LemanHLA Vegetable Crew: D. Oudman

This project was supported by the U.S. Department of Agriculture's (USDA) Agricultural Marketing Service through grant (SCBG-15-002). The contents of this report are solely the responsibility of the authors and do not necessarily represent the official views of the USDA.

Pinney Purdue Ag Center, Wanatah, IN

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growingformarket.com

Many Online Information Resources

hightunnels.org

Facebook groups (four season farming community)

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Hoophouse Environment Management, J. Biernbaumwww.hrt.msu.edu/uploads/535/78622/HT-LightTempManagement-2013-10pgs.pdf

MSU student farm high tunnel scheduleswww.ncipmc.org/glvwg/pdfs/amGeneralHighTunnelPlantingSchedule.pdfwww.canr.msu.edu/hrt/uploads/535/78622/HTScheduleandRotation-14pages.pdf

Johnny’s Selected Seeds Winter Growing Guidewww.johnnyseeds.com/growers-library/vegetables/winter-growing-guide-high-tunnel-scheduling.html

What Crops?Mizuna, Arugula, Spinach

10-28

DS 10-10(Mizuna)

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27 26

Lettuce - SalanovaTaken 1-27

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Turnips and Radishes

+ beet, carrot (but consider versus storage crop)

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Days to Harvest vs. Planting Date Darkibor Kale

Days to harvest increases with later plantings. Late Oct-Nov. plantings not ready for harvest until next year, if at all

TransplantDate

Days to First Harvest

First Harvest

Date

Aug 30 28 Sept 27

Sept 15 26 Oct 11

Sept 29 42 Nov 9

Oct 14 98 Jan 20

Oct 28 – –

Nov 11 – –

Days

to H

arve

st fr

om T

rans

plan

t

Transplant Date

PPAC 2016 29

Marketable Wt. (lb. per 100 sq.ft.) vs Transplant DateDarkibor Kale

(Harvests 9-27-16 through 3-14-17)

Yield decreases with later plantings: delay kale transplant to 9-15 from 8-30 and harvest only 67% (2/3rds) as much.

TransplantDate

RelativeYield

$/100 sq.ft.*

Aug 30 100% $ 960Sept 15 67% $ 641Sept 29 28% $ 268Oct 14 4% $ 42Oct 28 0% $ 0Nov 11 0% $ 0

*Price of $7/lb. Average at Bloomington, IN, Winter Farmers’ Market between Nov 28, 2016 and April 30, 2017. www.purdue.edu/hla/sites/hortbusiness/price-reports/

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Salanova Red and Green Reef Lettucein High Tunnels

Days to Harvest from Transplantvs. Transplant Date

TransplantDate

Days to First

Harvest

First Harvest

Last Harvest

Aug 30 30 Sept 29 Dec. 13

Sept 15 28 Oct 13 Dec. 13

Oct 14 49 Dec 1 Apr 18

Feb 7 70 Apr 18 May 23

Feb 21 56 Apr 18 May 23

Mar 8 56 May 3 May 23could have continued harvest of Oct. 14- Mar. 8 plantings

PPAC 2016 31

Gazelle Spinach in High Tunnels

Days to Harvest from Seeding

Day

s to

Har

vest

SeedDate

Days to First

Harvest

First Harvest

Aug. 31 28 Sept 28

Sept 14 28 Oct 12

Sept. 29 36 Nov. 3

Oct. 13 48 Nov. 29

Oct. 31 120 Feb. 27

Nov. 11 126 Mar. 16Last harvest for all planting dates was March 16, 2017

PPAC 2016 32

Gazelle SpinachMarketable Yield (lb/100 sq.ft.) vs. Seed Date

For every day delay in seeding lose 1.54 lb. per 100 sq.ft.

For 1 week lose 10.8 lb. per 100 sq.ft.At average spinach price of $10/lb. that is a loss of $108/100 sq. ft.

Yield through Mar. 17, 2017PPAC 2016 33

Radishes: Days to 1st Harvest vs Plant Date

4/5/2017

SeedDate

PredictedDays to

First Harvest

First Harvest

1-Sep 24 25-Sep

15-Sep 28 12-Oct

1-Oct 34 3-Nov

15-Oct 41 25-Nov

1-Nov 57 28-Dec

15-Nov 84 6-Feb

EP 2016

Days

to H

arve

st

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J F M A M J J A S O N D J

Hours of Daylight

10

12

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Daily Light Integral (DLI) DLI < 10Mid-Nov. to End of Jan.

Shorter days mean less light, so longer time to harvestDaily Light Integral vs Date

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Ave. Temp or Growing Degree Days

Growing degree day accumulation determines how quickly plants grow

(High + Low) – 40 = GDD402

Example: [(60+26)/2] – 40 = 3 GDD40

Lower average temp and fewer GDD mean longer time to harvest

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Growing Degree Day Bar Graph by Month

Outside Cool tunnel (minimally heated)

Cold tunnel (above cover)

Cold tunnel(under cover)

Oct

3

Nov

22

Mar

2

Apr 2

1

Oct

3

Nov

22

Mar

2

Apr 2

1

Oct

3

Nov

22

Mar

2

Apr 2

1

Oct

3

Nov

22

Mar

2

Apr 2

1

GDD accumulate very slowly in winter.

Plan to get crops near harvest size by mid-Nov. Crops start to grow again

in Feb.

Vernalized crops will bolt and bloom as

temperatures increase in spring.

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What Resources Are There for Scheduling?

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Coleman, 2009(note: when we make these types of graphs for spinach or radish, the steep part comes in October)

Coleman Planting Schedule

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JSS Winter Growing Guide

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www.timeanddate.comBaby Kale in MuncieLast 10-Hour Day == Nov. 13Seed last week Sep. first week Oct.Kale (full leaf) in MuncieStart TPs Aug. 1-15, TP Sep. 1-15

MSU table

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Coleman, Eliot. The Winter Harvest Handbook. 2009. p.11

Harvest Season of Cool-House Crops (Coleman 2009)

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Coleman, 2009 43

Planting Table from Coleman 2009

Cumulative Growing Degree Days40 Under Row Cover Oct. – Dec. 2016

Predicted Actual

Clay Bottom Eden Prairie River Ridge

Pred-ActCumGDD40UH-vs-date-byLOC_OCT-DEC2016 44

Crop

GDD40 to 1st

Harvest*

MinimumGDD40 to 1st

Harvest

Location/Year

Kale ‘Darkibor’, leaves, 8-in blade

826 533 PPAC 2016

Spinach, ‘Gazelle’ leaves, 7 cm blade

845 320 PPAC 2016

Lettuce, ‘Salanova Red’and ‘Green Reef’, 6-inch head

865 475 PPAC 2016

Radish 770 440 EP 2016

Growing Degree Days to Harvest for Selected Crops

*Transplant or seed about Sept. 1 45

A Growing Degree

Day Approach

to Estimating

Days to Harvest

research in progress...

Data Table=PtototypeData-for-graphing.jmp

Days to Harvest vs Planting Date, 600 GDD40 Crop

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How do predictions compare to observations??

Days to Harvest vs Planting Date, 600 GDD40 Crop

Spinach, 2016, Wanatah

9/138/31 9/29 10/15

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Key Points for Scheduling

• Plant early for shorter time to harvest and higher yield.

• Plan for sequential harvest of crops that reach ~size by start of ‘Persephone’ (10-hour days). Continue with sequential plantings that resume growth as ‘Persephone’ ends.

• Take into account crop hardiness and vernalization.

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Resources for Scheduling• Use past experience to determine days to harvest for

different planting dates –Coleman–Schedules published by others

• Identify 10-hour daylength and count back to plant date–Johnny’s Selected Seeds Planting Tool

• Use knowledge about temperature in the high tunnel and crop growing degree day requirement to determine days to harvest for different planting dates–Purdue research in progress

• Keep your own records to fine tune schedule

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Wooden Stake Records

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0

20

40

60

80

100

120

23-Aug 2-Sep 12-Sep 22-Sep 2-Oct 12-Oct 22-Oct 1-Nov 11-Nov 21-Nov

Days

to H

arve

st

Planting Date

baby lettuce

0

20

40

60

80

100

120

140

12-Sep 22-Sep 2-Oct 12-Oct 22-Oct 1-Nov 11-Nov 21-Nov

Days

to H

arve

stPlanting Date

spinach

Hartman, Ben. The Lean Farm. 2015. p.181

Keep your own records to develop ‘Coleman graphs’ for your operation.

Example from Clay Bottom Farm

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Example of Scheduling Based on DTM

Sour

ce: D

avid

Rob

b.

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Example of Scheduling Based on DTM - Mustards

0

10

20

30

40

50

60

1-Sep 1-Oct 1-Nov 1-Dec 1-Jan 1-Feb 1-Mar 1-Apr

Days to maturity from seeding for mustards

Source: David Robb. 53

Summer and Winter Crops Compete for

the Same Space

9/6 and 10/25/16

10/28/16 and 3/9/17

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Summer and Winter Crops in the Spring

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Vegetable Production Budgets for a High Tunnel, Iowa State University, PM3025

• How much of this gross $/sq.ft. is harvested in September? October?

• How much is from the first two weeks of harvest?

• How would it change if you stopped harvest at the end of August?

• ...started plants two weeks later in the Spring?

lb./

plan

t

2

4

6

8

017 Jul

24 Jul

31 Jul

7 Aug

14 Aug

21 Aug

28 Aug

Harvest Week

Yield of ‘Red Deuce’ tomatoes in a high tunnel, PPAC, 2017.

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Marketable Yield vs. Harvest Date for Four Transplant Dates Darkibor Kale

High Tunnel 1

PPAC 2016

Transplant Date

Aug. 30Sept. 15

Sept. 29O

ct. 14Lb

./Pl

ot

Harvest Date 57

Marketable Yield vs. Harvest Date for Four Transplant Dates Darkibor Kale

High Tunnel 1

Aug. 30Sept. 15

Sept. 29O

ct. 14

Lb./

Plot

PPAC 2016

Transplant Date

Harvest Date

Some leaves could be left on plants for harvest later in season

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Managing the Environment

• Solar radiation / light• Temperature• RH

• Structure considerations• Row cover management• Venting• Supplemental heat

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A Draft Framework for Thinking About Environmental Management

Time of Year Mode DangerSept. – Oct. growth, acclimating overheating

Nov. slow growth cold injury

Dec.-Jan storage, surviving, veryslow growth

cold injury, disease

Feb. – Mar. slow to faster growth cold injury, overheating, unwanted bolting

April growth overheating, unwanted bolting

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J F M A M J J A S O N D J

Hours of Daylight

10

12

14

Daily Light Integral (DLI)

DLI < 10Mid-Nov. to End of Jan.

Corresponds to Days less than 10 hours

Daily Light Integral vs Date

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RR_min_air-tempWITHOUTHEATED-vs-date-overlayRR_daily-radiation-and-DLI-graph 63

Min. Daily Air Temp Outside and In – Determines what will survive

Daily Solar Radiation and Light

Outside

Minimum temperature determineswhat will survive

Under row cover 5-10°F warmer than above, 10–20°F warmer than outside

Daily Minimum Air Temperature Outside and in High Tunnel (unheated) and Low Tunnel,RR, 2015-2016

Air temp and solar radiation in Feb. Data from CB, 2016

Air Temperature and Solar Radiation for a Week in February 2016

Air temp in tunnels increases quickly when the sun comes out.

Air under row cover in tunnel

Air above row cover in tunnel

Air outside

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Air temp and SR in Feb, 1 day Data from CB, 2016

Temperature Increases Quickly When the Sun Comes Out!

Air under row cover in tunnel

Air above row cover in tunnel

Air outside

Data from Clay Bottom, 2016 65

Temporary side walls

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Row cover on

conduit, 4-season,

unheated

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Insert picture of venting tunnels, removing row cover, etc.

Row cover as a blanket.

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RR_ave_soil-temp-vs-date-overlaySepMarRR_daily-radiation-and-DLI-graph

Daily Solar Radiation and Light

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71RH_AirTemp_UHandHt_CB-2-17-2016.jpg

Relative Humidity and Temp

What’s a good way to reduce RH in a tunnel?

Vent

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How are You Using Row Covers?

• Do you use row covers?• Blankets? or hoops?• Single bed? or whole tunnel?

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What’s better: Row Cover on Hoops or Row Cover Blanket?

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Spinach Row Cover Trial

Row cover better than no row cover. No big difference whether row cover was on hoops or used like a blanket.This was only spinach, uneven plants stands, one year....

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Managing the Environment – Standard Daily/Seasonal Practices

• Watch forecast. Not just daily, but leading up to harvest to anticipate ideal windows for harvest. Monitor internal temperatures (if you have sensors)

• Anticipate venting and row cover removal in late morning and closing/covering in afternoon for temperature and RH management. Uncover to reduce RH, and increase solar radiation gain to soil. Vent to reduce RH, limit high temp.

• Multiple layers of row cover may be needed incrementally as temperatures drop.

• Do NOT remove covers early after freezing nights or you risk damaging plant tissue.

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Managing the Environment – Standard Daily/Seasonal Practices

• Some growers leave peak vents slightly vented at all times. Little air exchange will occur if no side wall or lower vents are open. Management is then reduced to side wall venting and row covers.

• Remove snow or ice to limit structural stress• Emergency heater for extreme low temp situations?• Insulate end walls, and north walls?• Row covers not typically used in minimally heated tunnels. Low temp

threshold set at ~28 F (depends on crops and your fortitude)• Make close observations by crop, variety, weather conditions, mgmt., and

keep records.• In fall keep tunnel vented to “harden” off or “acclimatize” the plants to low

temps until absolutely necessary to close. Don’t baby your plants!76

Minimally Heated TunnelsBenefits

–Less hardy crops survive for more diverse mix in mid-winter–Faster growth means higher yield–No need for row covers

Heating systems–Air - unit heaters are common–Soil - hydronic, air-to-air, electric

Temperature Management–What temperature? 28? 33? 40?–Manage for average daily temperature instead of minimum?

–Flexible based on sunny/cloudy weather?

Average temp: 22.6, 38, 37.5., 37.9. Total of hourly differences in temp vs unheated: 370, 358, 367.

USDA Virtual Grower – software for calculating greenhouse heating costs

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Logger and solar panel at EP

Solar Radiation and Air Temp. Sensors at RR

Light (PAR) Air Temp., and Soil

Moisture Sensors at CB

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http://wirelesstag.net/

Wireless Sensor Tags - Info

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Wireless Sensor Tag - Specs

80http://wirelesstag.net/

Wireless Sensor Tags - Output

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3-Sensor Temperature and Humidity Smart Home Environment System with My AcuRite

https://www.acurite.com/shop-all-acurite/environments/thermometers/thermometers.html

Accurite

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Some Suppliers of Environmental Monitoring EquipmentAcurite www.acurite.comDavis Instruments www.davisnet.comExtech www.extech.comHobo onsetcomp.comLascarelectronicswww.lascarelectronics.comMeter metergroup.comMonarch monarchinstrument.comSpectrum Technologies, Inc. specmeters.comWireless Tag wirelesstag.net This list is not meant to be all-inclusive.

Inclusion on the list does not indicate endorsement nor does exclusion indicate lack of endorsement. 83

Fall and Winter Vegetable Production in Protected Structures

• Planting date matters for yield, but other factors will influence planting• Planting date greatly influences days to harvest• Plan harvest based on market needs • Tools available to help you schedule plantings, but keep your own records • Consider trials on your farm: planting dates, row cover management,

varieties• Sunlight drives heat, soil is main heat sink• Vent and use row covers to manage temperature and RH• Monitoring equipment available at reasonable cost, but line of sight is a

factor

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Liz Maynard, Purdue UniversityNathan Fingerle, River Ridge Farms

Ben Hartman, Clay Bottom FarmDavid Robb, Eden Prairie Farm

Collaborators and Funding This project was supported by a NCR SARE Partnership Grant through sub-award H004403722 to Purdue University from USDA Award 2014-38640-22156 to the University of Minnesota. The views and conclusions contained herein are those of the authors and should not be interpreted as necessarily representing the official policies or endorsements, either expressed or implied, of the USDA or the U.S. Government.

Thank you!Consider applying for NCR-SARE grants! Farmer-Rancher, Partnership, R&E

James FarmerAnalena Bruce Indiana University, BloomingtonThis project was supported by the U.S. Department of Agriculture's (USDA) Agricultural Marketing Service through grant (SCBG-15-002). Its contents are solely the responsibility of the authors and do not necessarily represent the official views of the USDA.

Erin A. Bluhm

Israel S. Calsoyas

Purdue University, HLA