Western Mountains and High Plains
As mulch begins to decompose and diminish, weeds can more easily start to sprout. Renew mulch layers around trees and shrubs to 2 inches to prevent weed invasions and help retain soil moisture. Spread the mulch up to, but not over, the root flare at the base of the tree or shrub stems.
Monitor Water on Newly Planted Roses
Check on the moisture content of the soil of newly planted roses. Do not overwater as it will starve the roots of oxygen. Allow the soil to dry out slightly between waterings to allow better root growth.
As shrubs start to resume growth, and the spring-blooming varieties are in bloom, it's time to apply a general fertilizer, such as 5-10-5, with iron and sulfur for alkaline soils. If you prefer, spread a slow-release fertilizer over the root zone and lightly rake it in. Then water thoroughly.
Conquer and Divide
Perennials that have started to outgrow their boundaries are in need of division. Now is the time to take a heavy-duty spading fork and lift out old perennials and split them. Divide them into thirds and transplant them to new sites or share with gardening friends. Don't forget to add compost to the new planting site.
Thin Out Early Veggie Crops
As the rows of spinach, carrots, beets, lettuce, endive, and peas begin to fill in, it's time to thin them. Overcrowding can weaken the plants and doesn't allow for good air circulation. Be careful about pulling out seedlings so as not to remove large clumps. I find it easier to use tweezers to snip out unwanted plants and space them accordingly.