March in the Contra Costa Garden

March Garden To Dos

General Garden Care

• Check drip systems: replace clogged emitters, filters, repair leaks, uncover sprinkler heads and flush.
• Fertilize lawns, fruit trees and shrubs if needed once it stops raining and if needed.  Citrus will need nitrogen, although it is unavailable to the plants until the soil warms.
• Fertilize sparingly, using a slow release form—fertilizer run-off is a form of pollution.  Nitrogen has been depleted from most soils by the winter/spring rains.
• Aerate lawns when rains have stopped, top dress with compost.

Fruits & Vegetables

• Plant potato tubers, citrus by the end of the month.
• Plant herbs—most require full sun and well-drained soil.
• Plant seeds of beets, carrots, lettuce, radishes, spinach, borage, radicchio.
• Harvest strawberries.  Strawberries need 6 hours of direct light a day to ripen fully.
• Check the soil temperature—soil should be 60°F prior to planting summer crops.  Garden soils can be heated using clear or black plastic mulch.

Flowers & Landscaping

• Divide fall blooming perennials.  Start summer vegetables and flower seeds.
• Prune azaleas and camellias that have finished blooming.  Fertilize with coffee grounds…it’s a good source of nitrogen and lowers the pH.
• Plant summer blooming bulbs: Canna, calla lilies, Caladium, Dahlia, Gladiolus, lilies, Nerine, tuberose, tuberous begonia, Tigridia, Watsonia.
• Plant perennials from 4” pots.
• Fertilize roses as they begin to leaf out. Alfalfa pellets are a good slow-release form of nitrogen.

Garden Pests & Diseases

• Wash off spittle bugs if they annoy you—they are primarily a visual nuisance.
• Wash off aphids before population builds up.
• Control snails and slugs – handpick, trap or use iron phosphate baits.
• Check for scale crawlers with two-sided sticky tape. Spray with horticultural oil if found.
• Spray roses for powdery mildew.  A simple mixture is 2-4 teaspoons baking soda + 2-4 teaspoons lightweight horticultural oil in 1 gallon of water.  Mix well and spray to cover all foliage.
• Spray apples, pears, loquats with Bordeaux mixture during blossom time for fire blight control.
• Spray stone fruit (apricots, peaches, plums, cherries, etc.) for brown rot during bloom time.

For More Information

• UC IPM Pest Note on Aphids
• UC IPM Pest Note on Snails & Slugs
• UC IPM Pest Note on Scale
• UC IPM page on Horticultural Oil
• UC IPM Pest Note on Powdery Mildew
• UC IPM Pest Note on Bordeaux Mixture
• UC IPM Pest Note on Fire Blight
• UC IPM page on Brown Rot