Gardening and plant placement in an overcast climate

July 5, 2013 2:37 PM

How does living in an area with near-constant overcast skies affect the placement of plants that are labeled "Full Sun", "Part Sun/Part Shade" or "Shade"?

Disclosure: I'm pretty knowledgeable about plants but I've never been able to find a satisfactory answer to this question: If a large part of your garden's growing season has overcast skies (like here in San Francisco's Outer Lands neighborhoods) and thus diffused light with few sunny or shady spots, do the normal rules about plant placement apply?

I suspect that having ample diffused light during the longest days of the year means that some "Sun/Full Sun" plants might actually do okay in areas that would normally be in shade during sunny days (and vice versa for some "Part Shade/Shade" plants). Your wisdom is humbly appreciated, mighty hive mind.

posted by echolalia67 to Home & Garden (4 answers total)

Best answer: As someone who lived in England for 7 years and had a fantastic garden for 3 of them the benefits are almost all positive. I grew cacti and succulents in a greenhouse beneath the mythical English sun. Everything grows and there is much less to worry about with regard to drying out or sun bleaching.

I found that the guidelines were pretty much meaningless in the UK. I grew shade loving ferns in full sun with no problem. I grew sun loving flowers in the shade and I barely ever watered anything.

Now that I live in Chicago I notice the rules are completely different. Full sun is incredibly full sun and plants will dry out in a blink even during the wettest half year on record.

I think the guidelines are more about what can stand full sun rather than what can survive in partial shade.
posted by srboisvert at 3:44 PM on July 5, 2013 [2 favorites]

As far as veggies go I think you will have a harder time growing some produce that really need a ton of sun like watermelons, but others such as lettuce and the cabbage family will do very well. If you have a long season you'll probably be okay for pretty much everything.

Full shade plants I would still plant in shade. A few unusually sunny weather patterns could hurt them.
posted by meta87 at 6:25 PM on July 5, 2013

Response by poster: I have my tomatoes in ersatz greenhouses (for the added heat as well as for protection against blossom rot & powdery mildew), so yeah it took some very hard-won experience for me to learn how to grow heat-loving veggies in SF. On the other hand, lettuces, chard & kale do great year round here as long as they have regular water & a bit of shade on the rare hot day.
posted by echolalia67 at 7:12 PM on July 5, 2013

It's more about the extremes of heat that too much direct, unfiltered sun can provide. I'm also in the fog zone in SF and "full sun" plants do fine in my yard. Plants that require shade or part shade definitely can get overexposed in my foggy yard. Sloat Garden Center by the zoo is a great resource for you. In this article on growing herbs, they suggest that the sun exposure still "counts" under foggy conditions.
posted by otherwordlyglow at 6:38 AM on July 6, 2013