What to mulch a flower garden with for the winter: peat, compost, bark or fallen leaves

Winter mulching is not so much «insulation» in the everyday sense as protection of roots from sharp temperature fluctuations. The main danger is not the frost itself, but the alternation of daytime thaws and nighttime frosts, which tears thin absorbing roots and pushes young plants to the surface. Mulch works like a thermos: it does not warm, but smooths out the amplitude of fluctuations.



Let's consider four popular materials and what plants they are best suited for.
 

Peat retains moisture well and protects roots from sharp frosts.

Pros. Dry peat retains heat and does not cake. Ideal for heavy, depleted soils prone to crusting.

Cons. It has high acidity and, when dried, forms a dense crust itself. In its pure form, it can acidify the soil more than most flowers need.

At the same time, high-moor (acidic) peat is excellent for mulching rhododendrons, heathers, hydrangeas, blueberries. Lowland (deacidified) peat - for most other flowering crops. Layer - 3-5 cm.
 

Rotted compost is both mulch and top dressing.

Pros. Enriches the soil with nutrients, attracts earthworms and improves soil structure. Suitable for plants of all types.

Cons. May contain weed seeds. Requires time to prepare (matures for at least two years). So that it is not washed away by rains, it is often recommended to sprinkle a coarser material on top, such as wood chips.

In general, this is a universal option for roses, peonies, delphiniums and most perennials. Layer - 3-5 cm.
 

Bark (especially pine) is one of the most durable types of mulch, keeping the flower garden looking neat for up to three years.

Pros. Perfectly evens out the temperature, protecting from freezing and thawing. Slightly acidifies the soil, which is useful for some crops.

Cons. During decomposition, microbes absorb nitrogen from the topsoil, so under vegetable crops or annuals, bark must be used with caution. May attract mice that like to winter under such cover.

Roses, ornamental flowering shrubs, perennials, as well as conifers, blueberries and rhododendrons (pine bark) winter perfectly under bark mulch. Layer - 5-7 cm.
 

The most affordable material, which also serves as free fertilizer.

Pros. They cover the soil, serve as food for earthworms and soil fungi, and by spring they rot, enriching the earth. Under a leaf blanket, tender plants winter perfectly.

Cons. Fresh leaves can rot or acidify the soil. Pathogens can overwinter on leaves from diseased trees. The layer of leaves must be chopped, otherwise they cake into a dense layer.

Phloxes, lilies, irises, roses, large perennials and bulbous plants will be happy with such a cover.

Remember that you need to use only dry and healthy leaves (birch, maple, oak, chestnut). Layer - 8-10 cm (taking into account shrinkage).
 

Mulch after the first stable frosts, when the soil has already frozen. Early covering on warm soil delays the transition of plants to a state of rest and provokes their rotting.

Leave 5-10 cm of bare earth around the stem or trunk. A dense «volcanic» mound at the base leads to rotting of the root collar and creates ideal conditions for rodent attacks.

To sum up: the choice of material for winter mulching should largely depend on which plants you are going to cover, as well as on what is easier to get in your conditions.