Do you have bulbs or perennials in your flower beds? The best way to protect them from fluctuating temperatures is by mulching. Fluctuating temperatures can heave your plants and bulbs right out of the ground and damage or kill the plant. Three to four inches around trees and one to two inches in your flower beds is sufficient.
If you mow and bag your leaves you get a great shredded/mulched mix to put on your flower beds. This a great solution to where to put those leaves if you don’t have a compost pile – but – you have to wait til the ground is frozen before applying. The winter rain and melting snow will take the nutrients from the decomposing mulch and distribute the nutrients to the soil for your plants to use.
Mulch also keeps the soil warm and encourages continued growth through the cold months. When Spring finally arrives those roots will be stronger, the plant will be healthier and will require less water.
If you decide to blow leaves into your garden keep a watchful eye out in Spring for when bulbs and plants start to emerge. Because those leaves are large and flat they can smother new growth. Be sure to remove this mulch early so you don’t have yellow spindly growth.
Other materials that can be used are straw, grass clippings and pine needles. These will not smother like the whole leaves do and can be either worked into the soil in Spring or removed.