Many years ago now, when I taught Environmental Science at Hollis Brookline High School, I introduced the students to the concept of limiting factors in the natural environment. These could be temperature, moisture, wind, solar radiation, chemicals or other factors of the environment that were critical to the survival of the organisms living there. For each limiting factor there would be a specific range of tolerance for each different type of organism. That meant that there could be a range from the least to the most of a particular factor within which the organism could survive. The point somewhere within that range where the organism did the best is called the optimum point. An environment could be at the optimum point for several factors but if one factor was outside of the range of tolerance, the organism would either die or escape by migration, hibernation or estivation. So this is a long explanation for a series of pictures of flowers in my gardens with differing ranges of tolerance.
On the south side of our garage the sun is intense and the soil is very dry. Sedums and sempervivums (hens and chicks) grow well in these conditions. They would not do well in a soggy dense shade. The row of lavender also on the south side of the garage grow best where there is full sun and well drained soil. The rose campion (perennial) growing by our extremely dry front steps have a wide range of tolerance. They most likely would be better of in a watered garden bed but despite their location they are flowering nicely right now.
Tomatoes in the greenhouse are thriving in the mid June heat. Even with the roof vents, side vents and door open with the exhaust fan going it still gets blazing hot in there in the middle of the day. They love it. I just have to make sure that they stay well watered. Green tomatoes the size of apples promise an early crop this year.
The canna are flowering nicely now due in part to the fact that I give them a very generous dose of water on a daily basis. They like it soggy if possible. On tghe other hand the golden hakune grass in the very dry shade of Japanese maple has been looking this good with no additional water or fertilizer for the last ten years. That’s my kind of plant!
The McKenna’s Giants columbines by the greenhouse door were grown from seed two years ago. There are others located in our dry shade garden that look not quite as good as these. This is a plant with a wide range of tolerance for sun and moisture but will do better, the closer the conditions are to it’s optimum points.
The annual flower boxes in the greenhouse garden are doing quite well right now. Due to the fact that there is a limited amount of soil for the plant’s roots however I have to be vigilant in keeping them well watered with water soluble fertilizer added every week. The water not only keeps the plants hydrated but also cools their roots that are exposed to the heat of the sun more than other plants in the garden beds.
Gardening during this time of drought is a challenging enterprise. Watering must be done on a regular and frequent basis or the plants can quickly succumb to the elements. If the garden plan puts plants in spots with too much or too little sun, they can die. Some plants are very resilient and will grow no matter where they are planted. Thank goodness for them!
New Hampshire Gardening 
It certainly is a balancing act of heat, sun, and water. I’ve never seen giant Columbine – wow, they’re big. You are certainly going to have a fine harvest of tomatoes along with many other things.
We also have the smaller native columbine in our gardens. They aren’t as showing but they are still nice in their own way.