Hobby Greenhouses and Other Growing Structures

1. Hobby Greenhousesand Other Growing Structures Ward Upham Modified By Dennis Morgeson

2. Questions That Must be Answered • What do you want to accomplish with your greenhouse or other structure? • Start plants early • Extend the season • Overwinter plants • Grow year-round • What can you afford?

3. Start Plants Early • Light Garden for Germination and early growth • Cold Frame and Hotbed to grow to transplant size.

4. Coldframes & Hotbeds • Coldframes • No supplemental heat • Hotbeds • Supplemental heat.

5. Supplemental Heat • 12 to 18 inches of manure under hotbed with 4 to 6 inches of soil on top • Plant when soil temp drops to 85 degrees

6. Supplemental Heat • Manure • Electric cable

7. Coldframe & Hotbed

8. Conserving Energy

9. Conserving Energy

10. Extend the Growing Season • Hoophouses (High Tunnels) are relatively inexpensive (compared to greenhouses) • Greenhouses ($20/sq ft) High Tunnels ($.50/ sqft)

11. High Tunnels • Single layer of plastic • No heat or cooling (other than venting) • Irrigation a must

12. High Tunnels • Tomatoes ripen 3 to 4 weeks earlier in spring • Tomatoes can be harvested an additional 3 weeks in the fall.

13. Overwintering Plants • Coldframes

14. Overwintering Plants • Greenhouse

15. Greenhouse? Discarded crates • Did buy plastic

16. Overwintering Geraniums

17. Heater

18. Growing Year-Round • Considerations • Winter growing difficult due to limited quantity and intensity of light • Winter growing expensive due to fuel costs • Summer growing difficult due to temperature control and watering demands. Need to have some type of shading. • Hobby greenhouses often lack adequate heating and cooling to grow plants year-round

19. Locating a Greenhouse • Sun all day (or most of the day) is best for most (not all) plants

20. Locating a Greenhouse • Sun all day (or most of the day) is best for most (not all) plants • If must choose between morning sun and afternoon sun, choose morning sun • Normally want full sun but may help to shade late afternoon sun during the summer

21. Types of Greenhouses: Lean-to Line Drawing Courtesy of West Virginia University

22. Lean-To Greenhouse • Advantages • Least expensive • Easy access • Insulation for and from adjoining structure • Disadvantages • Size limited by structure • Dirt and insects tracked into adjoining structure • Moisture

23. Types of Greenhouses: Free-Standing Line Drawing Courtesy of West Virginia University

24. Free-Standing Greenhouse • Advantages • More flexibility in location and use • Easy expansion • Private Get-away • Disadvantages • More difficult access • Separate utilities must be run • Higher energy costs

25. Types of Greenhouses: Pit

26. Pit Greenhouse • Advantages • Less energy required to heat and cool • Temperature more constant • Disadvantages • Access more difficult • Need sump pump to get rid of excess water • More expensive to build

27. Glazings • The more light transmitted, the better • For every 1% reduction in light received, there is a 1% reduction in plant growth (unless you are over 3500 foot candles of light)

28. Types of Greenhouse Coverings Above info from University of Arkansas

29. Other Comments • Glass: Heavy and subject to breakage • Poly film: Cheap but short-lived. Must be UV treated. Best if inner layer is IR film that is anti-condensate. • Polycarbonate: Can be scratched but more resistant than acrylic. Also, less flammable than acrylic. High expansion and contraction • Acrylic: Easily scratched, flammable, lower impact resistance than polycarbonate. Also, high expansion & contraction

30. Plycarbonate, Acrylic, Fiberglass • Panels • Roles

31. Sheet Poly (Plastic) http://www.simplifiedbuilding.com/blog/using-snap-clamps-to-build-a-greenhouse-for-under-150-video/

32. Plans • http://bioengr.ag.utk.edu/extension/extpubs/PlanList97.htm

33. Greenhouse Environment • Heating • Cooling • Air circulation • Ventilation

34. Ideas? http://www.ericsprojects.com/?page_id=228

35. Double Use? Chicken Tractor Too

36. Ideas

37. Kits?

38. Ventilation • Roof vents can be operated by solar powered • Need vent for cool air (doors or dedicated vents.

39. Air Circulation • Fans • Helps cut down on disease

40. Heating • Gas (7,000 BTU @ $649) • Electric (7,600 BTU @ $324) 240 volt • Wood

41. Heater BTU Rating Needed Varies With • Size of greenhouse (Sq ft and height) • Exposure • Coldest temperature expected • Free-standing or lean-to

42. Cooling • Shade cloth • Often reduces sunlight by about 50%.

43. Cooling • Evaporative (Swamp) Cooler for greenhouses 200 sq ft or smaller. • How well works depends on relative humidity • Cost $550 to $1500 for “box” models.

44. Cooling • Can also place evaporative pads along one side of greenhouse for greenhouses over 200 square feet.

45. Benches

46. How to Water Properly • Allow enough time between watering to allow most of the water to be used. Roots must have oxygen. • Apply 10-15% more water than container will hold to leach salts. All fertilizers are salts.

47. The End