March 2012 Garden Tips

Fertilize your roses – they should receive their first application at bud break and then once a month thereafter
Fertilize other perennials that are emerging from winter dormancy.

If you have a lawn, begin feeding. If you use organic fertilizer, you’ll only have to do it once every six weeks or so.

Plant summer bulbs such as gladiolus, dahlia, callas, amaryllis and lilies.
Apply Sluggo (non-toxic to pets, children and wildlife) to deal with snails, which are hatching in the garden now.
Prune summer-flowering shrubs such as Crape Myrtles (anything that blooms on new wood).

Watch carefully for aphids on tender new growth and use insecticidal soap or spray with water from the garden hose as necessary. We typically are not warm enough in March for them to be much of a problem, but be alert if we have an early heat wave.
Skip the visit to the gym and practice aerobic weeding instead – pull out what you can by hand – if you catch the weeds before they go to seed you can put them on your compost pile. However, stay out of the beds if they are sodden from the rains to avoid compacting the soil.

March is prime spring planting time for trees, shrubs and perennials, as long as the soil isn’t too wet. Now is the time to get new plants established so that they have time to develop some roots before it gets too hot.
Very hardy flowers can be planted 4 to 6 weeks before the average frost-free date (which in Sonoma County is April 15). You can sow indoors warm-season flowers such as: ageratum, celosia, cosmos, marigolds, sunflowers, zinnias, and so on.
If you’ve started plants in peat pots indoors or in a coldframe or greenhouse, make sure that when you transplant them into the garden, you either bury the entire pot completely, or cut off the part that will be above ground. That excess portion will suck moisture out if exposed to the open air.

Feed your compost pile: fertilizers with a high nitrogen content will stimulate compost’s decomposition process, and if you’re in a hurry for some compost, you might want to add some good sources of nitrogen to the compost heap now…(alfalfa meal, blood meal/dried blood, cottonseed meal, fish meal are just a few).

Use newspaper and mulch to discourage unwanted grass or weeds. A few layers of newspaper, topped with mulch to hold it in place, over time will choke off any vegetation. By the end of the season, the newspaper, along with the dead grass and weeds should have decomposed and become compost. Don’t use colored newspaper because the ink often contains metals and could be toxic.

Check on your ornamental grasses. Those that are not evergreen should be cut back within a couple inches from the ground to make way for the new shoots. Over the winter, their dead stalks provided some protection for the crowns. Now the dead stalks and blades are simply in the way. To make cleanup easier, tie a belt or a rope around the grass before cutting, and then simply pick up the bundle and put in the compost or shredder pile.

DON’T cut back the evergreen grasses (such as Carexes or Helictotrichon)! Use your hand or a small rake and tease out the dead blades.
Remember, the last frost date in Sonoma County is April 15th. Don’t get fooled by any heat spells into thinking that spring is here for good! A few years ago we had frost on April 23rd and it threw us all for a loop.

Information Desks:
Santa Rosa: (707) 565-2608
M-F 9-12 1-4
Sonoma: (707) 938-0127 MWF 1-3
email: mgsonoma@ucdavis.edu
(If clicking this link doesn't work, type the email address in your email program)
or bring plant problems in for analysis
Locations/REQUIREMENTS

Donate to Master Gardeners

Become a Master Gardener