Gardening Insights From Edwards Greenhouse

Let the Sun Shine!

I recently read a paper done by the Mayo Clinic.To read click here. (published in June 2013,) It  “shed some light” about the need people have for sunlight as a significant source of vitamin D. We learned early in life that the skin produces vitamin D with sun exposure, and scientists continue to study the importance of vitamin D. The sun is also obviously life-sustaining for herbs and veggies and other plants as well. The relationship living creatures have to the sun is fascinating and essential.

According to the paper, Vitamin D for Health: A Global Perspective, low vitamin D in humans has been found to increase the risk for diabetes, heart disease, many cancers, autoimmune diseases, cognitive decline, pregnancy complications, bone density, allergies, and frailty. It is estimated that between 200 and 2000 of our genes are responsive to vitamin D. If your vitamin D levels are good, your genes function more efficiently. If inadequate, they may function poorly, and the genetic expression of poorly functioning genes is chronic illness.

The paper states,

Humans obtain a considerable amount of their vitamin D requirement from sun exposure. Although excessive exposure to sunlight increases the risk of nonmelanoma skin cancer, which is easy to detect and easy to treat, there is no evidence that sensible sun exposure, as our hunter-gatherer forefathers likely experienced, increases risk. More importantly, the most deadly form of melanoma skin cancer that occurs on the least sun-exposed areas is less likely to occur in adults who have outdoor occupations. Therefore, it is not unreasonable to consider sensible sun exposure as a good source of vitamin D.

It goes on to say,

For a white person, if 30 minutes of June noontime sun would cause a mild sunburn, then 10 to 15 minutes of exposure followed by good sun protection should be sufficient to produce adequate vitamin D. There is no need to ever expose the face because although it is the most sun exposed of all the body areas, it provides little vitamin D. A free app,, provides the user with information about sensible sun exposure and vitamin D production.

Scientists aren’t entirely sure, but as many as 91% of Americans with dark skin pigmentation are vitamin D deficient because darker skin requires more sun to generate the same vitamin D as fairer skin.

So gardening outside, once again, is found to be healthful! That said, dermatologists, among other health care professionals, encourage wearing sunscreen to combat sun damage to the skin.

What are the sunlight needs of herbs and veggies? They need the sun too!

Members of the nightshade family including tomatoes, peppers, and eggplant need full sun. Strawberries, and vining crops such as melons and cucumbers, and members of the Allium family including onions, garlic, shallots, leeks, and chives also need full sun. Herbs such as basil, oregano, thyme, rosemary, sage, and lavender do best in full sun as well.

Lettuces and greens need part sun. Morning sun and afternoon shade is good for blueberries and cilantro. Cole crops do best in cool places. They include: Brussels sprouts, cabbage, cauliflower, collards, kale, kohlrabi, mustard, broccoli, turnips and watercress. Wild alpine strawberries do best in the shade.

May we and plants enjoy the life-giving sun and the gardening that sustains us!

Edward’s staff members are happy to provide support and advice throughout the gardening experience to strengthen each gardener’s skills at all experience levels.


Gretchen Weitemier

Occupational Therapist

Herbs and Veggies Worker