Finally, it's time to prepare for digging season

Every year vegetable gardeners who plant cool-season crops - including beets, carrots, radishes, a wide variety of greens, and more - wait until soil temperatures are consistently 50 degrees or warmer before they plant seeds or transplants in prepared garden beds.

How soon they can plant depends largely on the weather, of course. Warmer temperatures and soaking rains can be a gardener's good friends. But gardeners who are eager to start planting are happy knowing their fate does not depend solely on Mother Nature.

To help their soil warm faster and become workable sooner, these gardeners take steps to ensure their soil is organically rich. They know organically rich soil is darker and that dark soils warm up faster in the spring (and stay warm longer in the fall). They also know organic matter improves soil structure and drainage, and that loose, dry soils warm up faster than compacted soils that are damp or waterlogged.

There are many benefits for building healthy, organically rich soil. For many gardeners, one of the best is getting a head start for harvesting delicious, cool-season vegetables and greens.

Other projects for your garden this month:

General garden care

• To avoid long-term problems with compacted garden soil, wait until soil has dried out before tilling, planting or even walking on garden beds. Soil is dry enough when a handful formed into a ball crumbles when touched.

• Remove any winter debris from lawn and garden beds. Prune any broken branches immediately. Look for plants damaged by snow loads or rodents. Remove burlap screens that protected plants from winter winds or salt spray.

Trees and shrubs

• Spray fruit trees or large deciduous trees with dormant oil if aphids, scale or mites were a problem last year. Apply only on days when temperatures are over 40 degrees and there is no chance of freezing or rain within 24 hours. Avoid spraying on windy days.

• Prune fruit trees on a dry day in early March before buds swell. Sterilize pruning tools with a 10 percent solution of bleach. Fruit trees benefit from having their canopies opened up to increase sunlight penetration and airflow.

• Prune roses when forsythia begins to bloom. Make 45-degree cuts above a healthy bud, angled away from the center of the plants. Prune out dried, darkened and broken canes and any dead tips. If not done last fall, prune hybrid tea roses and grandiflora roses back to 12 inches to reinvigorate growth. Prune shrub roses only as needed to remove dead wood or very lightly shape.

• Fertilize woody plants four to six weeks before new growth begins only if they have shown signs of needing it. Routine fertilization is not recommended. If plants had poor leaf color, failed to flower or fruit, or had stunted growth because of depleted soil, consider using a slow-release granular fertilizer.

• Plant trees and shrubs before they break bud and when soil conditions permit. If spring weather is unusually wet, consider postponing planting until fall when plants are entering, rather than ending, dormancy.

Flowering plants

• Gently press back any perennials that heaved out of the ground over the winter. Mulch them with several inches of organic compost.

• As temperatures rise, gradually pull back mulch from around perennial crowns.

• Cut to the ground all perennials and ornamental grasses that were left standing for winter interest. Also remove winter debris, taking care not to injure emerging leaves.

Fruits and vegetables

• Prune raspberry bushes and reattach canes to a support system, if necessary.

• When a soil thermometer indicates soil temperatures are consistently in the 50s, sow seeds of cool-season vegetables that can be planted directly in the garden, including the root crops (beets, carrots, radishes, parsnips and turnips) and leaf crops (chard, loose-leaf lettuces, spinach, mesclun mix, mustard and collard greens, and kale).

• Small transplants of cool-season vegetables that should be started from seed indoors can be moved outside after they are slowly hardened off and soil is consistently in the 50s. This includes broccoli, the cabbages and cauliflowers.

Indoor plants

• Primrose plants can be discarded after flowering or planted in shaded, well-drained garden areas. Plants will go dormant during the summer and require heavy mulch to protect them from summer heat and winter cold.

• Repot houseplants, including orchids after they have flowered, if they have become root bound. Increase pot size by one inch. Change the potting soil/orchid mix but do not change the levels at which plants were situated in pots.

• Fertilize houseplants as they resume growing with very dilute liquid fertilizer or slow-release granular fertilizer for houseplants.

Denise Corkery is a horticultural writer at the Chicago Botanic Garden.