Autumn Light Landscape Design

Another early bloomer: bluets, also called Quaker ladies (though these particular flowers were sped up in a greenhouse environment). They're hard to get established in a native lawn, but if you're lucky enough to get them, they are beautiful. Behind the bluets in this native-plant container are wineleaf cinquefoil (Sibbaldiopsis tridentata), and blue-eyed grass (Sisyrinchium angustifolium). All three retain some foliage over the winter, and all feel at home in tiny gardens.

Why does mulch matter so much during winter? Leaf litter and snow cover insulate the ground during cold snaps. When it's -18C outside, the ground underneath stays comfortably between -5 and freezing. (The yellow line shows the ground temp under both leaf litter and snow; gray is when both are swept away. Blue is the air temperature.) Your plants' roots appreciate that warmth!

Warm leaf-covered ground also keeps insects alive over the winter. That's great for hungry wild birds, who will gleefully toss leaves aside to pick off the bugs underneath. It's also great for the survival of beneficial insects, including butterflies. But this graph came from a presentation on... ticks. They, too, will survive under leaf litter - and that's why you should be careful doing spring cleanup.