March 9, 2019
Yes, it’s still cold, grey and raining outside. Why in the world would you be motivated to even start thinking about your summer garden? Maybe because you are tired of eating tomatoes grown in hothouses and are day dreaming about fresh burrata alongside a sweet, juicy, home-grown tomato, topped with chopped basil, EVOO and a sweet fig balsamic. There’s a lot you can do now that will benefit your summer garden, offering prevention and eliminating work and disappointment once the weather improves.
Let’s start with the state of the garden. The best way to jump start your summer garden is to keep your garden clean of plant debris, tomato cages and stakes left over from summer, and anything that could provide a shelter for pests that over-winter. Marin winters are mild, despite occasional frost and winter storms, and unlike many freezing cold areas, pests from the summer and fall continue to survive.
Disease can be reduced by removing decomposing plant materials. Decomposing plant materials can carry spores and other undesirable organisms that can also survive our winters and continue to live in the soil. In the summer, after a rain or overhead watering, spores and other organisms can be splashed from the soil to the plant.
A safe, nonchemical method for controlling soil-borne pests is soil solarization. This technique kills fungi, bacteria, nematodes, and insect and mite pests along with weed seed and seedlings by covering the soil with a tarp to trap solar energy. Once you have removed plant debris, and the soil is level and smooth, you can lay a transparent polyethylene cover on the soil surface for four to six weeks to be effective. Find out more on solarization at ipm.ucanr.edu/PMG/PESTNOTES/pn74145.html.
After you clear the soil, check your irrigation system for leaks, non-functioning emitters and sprayers, and repair or replace any faulty parts. This is also a good time to review the programmed settings on your irrigation controller.
The next step depends on weather conditions. If the soil is wet, you will need to wait until it is sufficiently dry enough to crumble when worked and has reached a temperature of 50 degrees. Soils high in clay content are easily damaged if worked when wet. Foot traffic and heavy equipment crush the soil’s pores, which limits plant’s roots access to nutrients, air and water.
Once the soil is dry, bring out your gardening shovel and rake and gently amend the soil. You can use organic or inorganic or a combination of these materials depending on your soil needs. Amendments modify the soil structures, which help to loosen soil providing better aeration and drainage and increase nutrient and moisture retention. A guide of the common amendments available in Marin can be found at marinmg.ucanr.edu/files/237708.pdf.
While you are waiting for your soil to dry out, start to design your plant locations. Consider intercropping, which is a method that helps to discourage pests. Increase the diversity of your vegetable patch by interplanting different vegetable crops with each other. When you add flowering herbs and annuals, pests may have a more difficult time locating their host plants. Tomato and basil plants are companion plants and are an example of interplanting.