Draft Greenhouse Model
Assumptions are 1.) Indeterminate variety tomato 2.) One initial purchase of 55 Bonnie indeterminate heirloom varieties required, subsequent plantings are from seed-saving and price included initial cost3.) Chard seeds bought new per season 4.) Entire area of greenhouse devoted to chard or tomato at one time 5.) No maintenance costs required- greenhouse structure built to withstand 5 years
Tomato
10.6kg/1.85m2= 5.7kg/m2/season
Total potential tomato production/season= 5.7kg/m2*11m2(total area greenhouse) = 63.02 kg tomatoes/season
Average Price of Tomatoes (USDA report) Southwest U.S.1 = 2.29$/kg
Potential Harvest Income= 2.29$/kg* 63.02 kg tomatoes/season= $144.3/season
Swiss Chard
8.7kg/1.85m2= 4.7 kg/m2/season
Total potential swiss chard production/season= 4.7 kg/m2*11m2(total area greenhouse)= 51.7 kg chard/season
Average Price Swiss Chard (FreshDirect)= $6.6/kg
Potential Harvest Revenue =$6.6/kg*51.7 kg chard/season= $341.22/season
ROI (assuming t=5 years)
Bonnie Tomato Plants= 9 plants/1.85 meters≈ 5 plants/m2*11m2=55 plants/greenhouse
Price Per Bonnie Tomato Plant≈ 4dollars/plant (averaged due to the different varieties in use)
$4/plant*55 plants= $220
Chard plants= 8 plants/1.85 meters≈ 4 plants/m2*11m2= 44 plants/greenhouse
1 seed packet/1.85 meters= 6 packets/11m2/year= $4.14*6=$24.84/year
Total Variable Cost = 24.84/year
Total Investment Cost= Initial fixed costs (construction and tomato purchase) + 5 year variable= $1800 +($220)+($22.84*5)= 2,134.2
Total annual revenue= $341.22 chard+ ($144.3*2) tomato= $629.82
Total revenue for 5 Years= $629.82*5=3,149.1
ROI Greenhouse= ($3,149.1-$2,134.2)/$2,134.2= 48% return on investment
Annualized ROI (5 years)
=[(1+.48)⅕-1]*100%= 8.1% annual ROI