Gardening Insights From Edwards Greenhouse

Boise Metropolitan Area: Higher Temperatures for Longer Stretches

The Boise metropolitan area has, for quite a while now, seen summers that have been incrementally hotter and longer periods of high temperatures. John Sowell, of the Idaho Statesman newspaper, wrote an article about this phenomenon for 2013. He writes in,

Since Jan. 1, Boise’s high temperature has reached 90 degrees or higher 70 times. That’s 26 days more than the 44 days that is normal for Boise, according to National Weather Service statistics compiled since 1898.

He goes on to say,

In fact, [the summer of 2013] -- June 1 to Aug. 31-- was the hottest on record for Boise, since record keeping began in 1875, according to the weather service.

What does this mean for gardeners and their gardens? Many herbs, and especially vegetables, hate going from dry-to-wet-to-dry-to-wet soil, and there is more of a danger of this with these weather conditions. The tomato family, including peppers, eggplants and tomatillos among others, and most vining crops including cucumbers, squash, pumpkins, gourds, and melons would benefit from measures to maintain a more consistent moisture and temperature, as well as water conservation. According to Better Homes and Gardens,, mulching is useful in this area. The “soil stays cooler and plant roots don’t stress from the heat.” And, “water evaporates more slowly from cool soil protected from the wind. If you mulch, you don’t have to water as much, which saves time, money, and a precious resource.” About how much mulch to apply and when, the site states, “For most mulches and soils, start with a layer 3-4 inches deep. Use newspaper as a decomposable barrier to keep weeds at bay. If the soil is dry, water it before applying mulch to pull weeds easier.” Mulch can be applied at any time. Organic mulches improve the soil. They include straw, “grass clippings, leaves, manure and compost.” talks about how living mulches can be a cover crop, such as clovers, hairy vetch, alfalfa, or rye grass. Living mulches are also effective for providing shade, retaining soil moisture, controlling weeds, helping reduce disease issues, and controlling some insect pests. “The best reason to use living mulch is because most cover crops, such as clover, feed nitrogen into the soil which in turn benefits your vegetable plants.” The cover crop is tilled in after its life cycle. The cover crop should be compatible with the plants around it and not susceptible to the same diseases as the vegetables it is meant to benefit. One of my co-workers in the Herb and Veggie department has also discovered that planting sweet potatoes among other vegetables can actually be useful as a type of living mulch as well! Also, some gardeners plant their plants closer together to “self-mulch”.

Water conservation is increasingly important for gardens and people as Boise’s weather patterns trend to hotter, and hotter for longer, summers. talks about how, “Food requires water wherever it is grown; growing food using water-wise techniques [especially mulching,] can minimize ecological and social stresses.”

What does the Boise metropolitan area’s changing weather patterns mean for our health and livelihood? lists benefits of water conservation, by including techniques such as mulching, that it , “Saves money, protects drinking water resources, minimizes water pollution and health risks, reduces the need for costly water supply and new wastewater treatment facilities, maintains the health of aquatic environments and saves energy used to pump, heat, and treat water.” states that the human body is between 50-75% water. This is one of the reasons why clean water is one of the most precious resources on the planet.

Weather patterns in the Boise metropolitan area may continue with this trend, perhaps becoming more pronounced over time. This underscores the need to care for our gardens using mulch, and use other water conservation techniques, to protect our food and water and live more sustainably.


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