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
USDA zones range from 8-9B
Sunset zones range from 7-17
Average max. temp. 63°F, 17.22°C
Average min. temp. 41.7°F, 5.4°C
Average rainfall 3.1”, 7.84 cm.
Historically, the last frost date is March 15, but keep an eye on the weather reports!
"The first day of spring was once the time for taking the young virgins into the fields, there in dalliance to set an example in fertility for nature to follow. Now we just set the clocks an hour ahead and change the oil in the crankcase." E.B. White, One Man's Meat, 1944
For real-time flood and high water information: http://www.usgs.gov/state/state.asp?State=CA