rooftop seed starting

It’s that time again!  Spring is around the corner and by now your first round of seedlings should be reaching for the sun… or more likely for their artificial light source.  Kick-starting the growing season through indoor seed starting can help ensure that your spring crops are in the ground and ready to roll as soon as the soil warms up.  But up on a windy roof, where can your seedlings find the shelter they need?

SHARE Food Program greenhouse ||  photo by Lauren Mandel

SHARE Food Program greenhouse || photo by Lauren Mandel

Skyline greenhouses, high tunnels or hoop houses, and even small sheds can protect your youngins from harsh rooftop winds and temperature fluctuations.  These structures can be designed similarly to those on the ground, with a few extra considerations:

1| Stabilization – The stability of rooftop structures begins with sound anchoring and bracing or cross-bracing.  How will the structure’s footings be secured?  What is the local snow load requirement?  Local building codes may affect the design of your rooftop greenhouse, so before banking on a glass or heated plastic structure, be sure to do your homework.  Consulting a licensed structural engineer may provide answers regarding local building codes, your roof’s load capacity, and methods for preventing structural shaking.

2| Electric hook-up – If a heated or grow light dependant seed starting structure is in the cards, where will the electricity come from?  Does your roof contain an electrical hook-up?  If not, how much will it cost for an electrician to install one?  For the sake of simplicity you may want to consider a passive solar structure, but keep in mind that rooftop temperatures will fluctuate wildly.

SHARE Food Program heirloom tomatoes ||  photo by Lauren Mandel

SHARE Food Program heirloom tomatoes || photo by Lauren Mandel

3| Water source – Seedlings’ notorious thirst must be satisfied with a water source.  Does your roof contain a point of connection?  If not, you’ll need to speak with a plumber about installing one.  When considering the use of harvested irrigation water, be sure to consult local codes about required filtration systems specific to crop production.

While some rooftop growers choose to start seedlings near their fields, others prefer to reserve valuable rooftop acreage for mature, productive plants.  When considering alternate locations try starting your babes within the building below or at an off-site location.  Go get started!

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