Gardening in March

With summer just around the corner March is one of the busiest and most important months in the Southern California garden. Some days will be wet and chilly, then come those wonderful days of warmth and clear skies. It is the perfect time to get outside.

In your vegetable garden, it’s too soon to plant heat-loving summer vegetables. Through March and early April in the foothill zones of 20 and 21 we will still get lows in the 40’s. The soil isn’t warm enough and often will be too damp to turn. However, you can still plant seeds for lettuce, radishes, mustard greens, and other quick growing cool crops that will produce in the next 30-60 days. Be sure to fertilize existing cool season vegetables, after regular winter rains the soil may need a boost of nutrients to finish spring crops. Don’t be in a hurry to cut off bolted radishes, bok choy, arugula etc. You can let these to flower to attract bees, beautify the garden and gather seeds for next season. Soon when the soil warms the plants can be removed.  

Bee on Bok Choy blossom

Your native plants need attention this month. They will be starting new growth as the days get longer and warmer. Add compost around the base of each plant, but not against the stem. You don’t need to turn it into the soil. Microbes and decomposers (fungi, mites, worms, millipedes, pill bugs, slugs, etc.) will break it down further and watering will help the plant draw the nutrients towards the roots.

Cut back old woody growth, shape oversized bushes and remove dead growth on all native plants and grasses to allow for new growth. Don’t cut back harshly anything that is in spring bloom, these plants should be trimmed after they are done blooming or in late Fall cool temps. You will only need to do this once a year, the rest of the year your native plants will grow well on their own.

Howard McMinn Manzanita spring bloom. Wait to trim until fall.

If you have newly purchased native plants not yet planted, this is a good time to get them in the ground to take advantage of spring rain. They will spread roots and be well established before the summer heat. You can plant later, as late as May, but your plants may struggle to get established and you’ll need to provide more supplemental water through the summer.

Now is the time to take care of the weeds before they take over. Use a hoe or a hand rake to quickly dislodge small weed sprouts poking up through mulch and growing in crevasses before they get deeply rooted. If we’ve had good spring rain, the weeds will be everywhere and may seem overwhelming. I try to do a little each day when I step outside with my dog or for a lunch break. There is great satisfaction by the end of the week seeing a whole area cleared. Then come Saturday I have time to do other projects!

I’m generally too busy in the spring to worry about sprinkler systems. (May and June are a good time to test all drip systems before the summer heat becomes intense.) This depends on the weather of course, if we have a dry winter and spring you’ll need to start supplemental watering in much sooner.

All these busy days outside this spring will pay off come summertime!