Naturalizing crocus gives the lawn spring color

Crocuses are ideal bulbs for naturalizing, for rock gardens or for planting under tall trees. They may be scattered in lawns, but their grasslike foliage must remain intact for at least six weeks before being mowed at a short height for best long-term results. Crocuses, which are planted shallowly, are easy targets for chipmunks and squirrels. The bulbs might require repellant products or light chicken wire screen placed directly over them at planting time. Blood meal or a granular repellant sprinkled on the ground after planting may help repel squirrels and chipmunks.

Clean up plant debris

After a killing frost, remove dead plant debris from annual and vegetable beds. Sanitation is especially important if you have had disease problems in your planting beds. Remove all diseased foliage or fruits and do not add affected materials to your compost pile, since most home compost piles do not get hot enough to kill disease organisms.

Stay off the (frosted) grass!

It is best to stay off the lawn when there is frost present. Frost on the grass indicates that water inside the leaves is frozen, so traffic on the turf can cause the frozen water in the cells to rupture. This kills or severely stunts the leaves. The symptoms generally appear purplish to black at first and progress to a straw color. When frost is very heavy, the cell disruption can occur at the crown and kill the entire plant. If there is no damage to the crowns, the turf will recover from the generation of new leaves. Once everything is frozen, it is less of an issue, as everything is solid so the cells can’t rupture.

• Tim Johnson is director of horticulture at Chicago Botanic Garden, chicagobotanic.org.