It was hot. Daytime highs in the low 30C but nights are cooler and the garden starts to look fallish. The leaves on the Box Elder, Prunus padus are yellowing, the Burning Bush Euonymous alatus has tinges of red. The same plants have been flowering for the last three weeks; Phlox paniculata, Monarda keeps going, Rudbeckias, Monkshoods, Aconitum, Roses as well as few other oddments. The Nepeta and roses are blooming again.

It is unusual to have daytime highs this high at this time of year at this latitude and some plants are confused as a result. Many plants are guided by both temperature and hours of light. When the temperatures resemble high summer but the hours of light are diminishing, no wonder some get out of their normal rhythm. Such was the case with a Prairie Crocus, Pasque Flower, Pulsatilla I saw this week blooming away in a forest clearing. It’s normal time of flowering is April and May.

The number of hours of light and dark for a plant to bloom is called ‘photoperiodism.’ Spring and Fall flowering plants require more hours of darkness. The number of uninterrupted hours of darkness is what determines when and whether a plant will bloom. Most people are familiar with this necessity for the Christmas cactus to have more that twelve hours of darkness to flower. The same applies to other short daylight plants such as Poinsettias and Chrysanthemums. When the opposite is necessary, more hours of daylight, these plants are known as long day plants. Most garden vegetables and summer perennials are long day plants. There are some plants that are not fussy and are day neutral. Nursery growers of seasonal bloomers, manipulate the hours of light to produce plants blooming at the ‘right’ time. The long days of higher latitudes are the reason why some long day plants, especially vegetables do so well in areas of Alaska and the Yukon. I have referred before to the ten pound bag of the sweetest fresh shelled peas we bought in the Anchorage market in September. Peas are a valuable cash crop in that area.

The Prairie Crocus was probably stimulated into blooming by both a short very cool few days we had in August and more hours of darkness. It thought winter had come and gone! No such luck. The plants food supplies will be depleted for spring so it may not bloom next year.

The garden, this last week:

A little test on the plants. I hope you recognize all the plants, which with the exception of Spaghetti Squash have been identified in previous pots. Squirrel is hanging out in his favourite bird box with the metal surround to prevent him using it. Toady was enjoying an outing on the grass.

Beyond the garden gate: