Managing Microclimates

Managing Microclimates

Matthew Noiseux
Jun 4, 2010

While the near end is in shade for the morning and late afternoon, the other end of the fence has sun from 8:00 a.m to 8:00 p.m!

After a year or so of playing around and taking notes up on our own roof we are still learning about what goes on all day and how it affects our plants' health. After we had good soil and kept everything watered it was supposed to be gravy, right? Wrong. Turns out our 'sunny space' was more complicated than that. So after the jump are a few notes of our own from discovering these differences. And if you have any of your own experiences it would be great to hear about it!

The urban environment really does affect how nature hits your plants. The effects can be quite immediate, and in the case of a rooftop you can have polar opposite growing situations from one end of the roof to the other!

Here are some things we came to consider (which we did not take seriously enough from the beginning) when putting out our own planters:

  • Consider how building shadows travel throughout the day. In our space a plant can move just two feet and get hours more or less sun. Temperature also is greatly affected. We noticed one tricky spot would get shadows in the morning, and then get them in the afternoon from another direction.
  • Consider how light hits and reflects off walls. When heat builds up on a wall - or a roof surface - it can reflect right back at plants that are close by. We had a few plants that could not take this radiating heat. It can also heat up planters, and hot roots can make for some unhappy plants.
  • Take note of the amount and direction of the wind and rain through the seasons. We had plants suffer from wind coming consistently in one direction, only to place them around a corner and have them be fine. We also have one corner that can get severe rain, consistent wind, and also gets more shade. It is generally a tough corner for us!
  • Are there any parapet walls or other structures that will shape how light, wind and warmth travel? One of our parapet walls acts as a shade and a wind-break, another collects heat and wind. Another planter is positioned as a windbreak for a smaller planter for veggies, helping to make a sunny little niche for our tomato and lettuce plants.
  • Are there any vents or mechanical equipment that might change growing conditions? A plant can live or die because of its proximity to a dryer vent or AC exhaust unit! Sometimes vents or exhaust can be redirected away from an area.
  • Pay attention to the material, size and color of your planters. Dark planters will absorb heat, as will metal planters. If you need cooler roots you might be able to affect the pot just by painting it white or sinking it into a larger vessel. Smaller pots will feel the fluctuations in temperature quicker and transmit that to the plant roots.

Controlling the climate by moving planters, grouping pots, and choosing appropriate plants that can take the conditions are all good steps to take. Another step might be to actually alter the space by using simple materials:

Gardening is an active and engaging hobby no matter where it is happening. In Maxwell's case he is busy keeping his place looking nice but trying to keep deer out. In mine, I am trying to keep roots cool and winds down. Every person who gardens seems to end up with a few stories and some hard-earned wisdom from the experience. Am looking forward to seeing what this season has in store!

Matt writes a weekly column on plants, flowers and gardening. Feel free to e-mail questions to matthew@apartmenttherapy.com

Created with Sketch.