We can hardly wait for spring in our Northern Plains region! It’s not uncommon to have lots of cool and erratic temperatures during spring, this year included. Now, as summer begins, the unseasonal sweltering days with little rain stress perennial vines like clematis. Its roots flourish with supplemental soil watering and mulch to slow moisture loss. Flowering begins!
Extended hot weather slows annual plant growth too, and fewer blooms result. After delays in planting this spring, the flower transplants at Plant Exchange were leggy. Clipping the stems with blooms encourages vegetative growth for the plants to get established. These annuals are just beginning to bloom again after pruning.
The 4th of July, mid-summer, is time to check the status of blooming container annuals and flowerbed perennials. If plants have nearly completed blooming, some can be rejuvenated to bloom again by pruning the stems below the flowers. Monarda, yarrow, and catmint are examples. An article in the July/August 2021 Northern Gardener and the August 2021 Fine Gardening magazines, both available at the Yankton Community Library, refers to other reasons and tips for pruning flowering plants.
Native plants are reliable pollinator attractors, even in hot weather. Just in time to celebrate Pollinator Awareness Week, migrating copper-colored Painted Ladies show up at the common milkweed in bloom here.
Monarch butterflies migrate through this region in the spring and fall. Hot or other unusual weather has to challenge Monarchs in many ways, including the location of milkweeds in bloom. That is reported in Katie-Lyn Bunney’s Monarch Joint Venture blog: kbunney@monarchjointventure.org While flowering milkweeds are linked with Monarch butterflies, many other insects benefit from them too.
Perennial and annual plants are adapters to hot weather. Their flowers accent the beauty of the season on the hottest of days!
Plant Exchange Blog 
Until recently, I would have said that hot weather there is comparable to average weather here, even though it sometimes gets hotter there than it does here. Some areas are getting some nasty heat now though, particularly the Pacific Northwest.
Great advice, thank you! Beautiful flowers. 😊
Blue Rock Horses Frederick County, Virginia bluerockhorses.com