On the other hand, darker soils may warm more slowly in spring due to higher moisture content. Soils also may be low in certain essential nutrients. Test the soil after adding organic material. Contact your Colorado State University Cooperative Extension county office for soil test information. Use organic mulches to protect perennials from severe drying where snow cover is not likely to remain during the winter.
Mulches also can be a disadvantage by delaying spring growth.
Remove them in early spring to allow the soil to warm up. Gradually acclimate annuals and perennials that are established in containers at the greenhouse or in the home. About two weeks before the anticipated planting time, reduce watering and expose the plants to increasingly longer outdoor conditions. If plants are well-rooted in the containers or are potbound, loosen the outside of the root ball before planting. When transplanting, use a water-soluble starter fertilizer available in Garden stores.