When I heard the 30 day forecast last week for no more rain, I said hallelujah! The spring rains have been great for our reservoirs, pastures, wildflowers and many perennials, and it has been wonderful to not worry about watering. But they have delayed soil work substantially in low areas and heavy clay and being the California gardener that I am, I’m ready to start gardening!  Lots of late rain can cause problems with some crops too, which I’ll touch on below.

 Now that we seem to have shifted from the rainy season to dry, our focus rapidly changes from helping the soil to dry out to conserving moisture. Mowing and weeding now will serve several functions – prevent weeds from going to seed, allow the soil to warm up, and remove hiding places for snails, slugs, earwigs, and even mice and other rodents. It also will reduce “wicking” of soil moisture from the deeper levels. I was skeptical of this concept for a long time, as my experience had been that if you bare the soil it dries out more quickly, which is true for the surface. But deep rooted and large leafed plants – like fava beans and wild radish – will pull substantial moisture from the soil on sunny, windy days like we’re having now. I learned this lesson first hand at Shone Farm one spring where the cover crop on one field was mowed and tilled under and on the adjacent field the cover crop stood for another month after a late rain. At planting time the section with the cover crop was bone dry and the bare field held beautiful moisture. Like all things in nature, each situation is different and there are many different factors that will determine soil moisture, but this is an important one to consider.  Mulching is a great way to conserve soil moisture and good to keep year round on most perennials and fruit trees, but in the vegetable garden, organic mulches will keep the soil cold now and can increase slug and earwig problems, so wait to mulch warm season crops until plants are established and soils have warmed. Today I saw an interesting way of getting around the bugs and mulch problem – individual copper collars around each young cabbage, broccoli and other cool season plants (which do not mind cool soil) - in a spring garden nicely mulched with straw. I do not like to use plastic mulch as it is not food for the soil and eventually has to go to the landfill. Loosened dark earth absorbs heat from the sun just fine.

 Without regular rain, the watering season will soon be with us. If you have not already, please read the Water Wise Gardening document on the iGROW site. Even with “normal” rainfall this year, water conservation is very important. Moving water around is the single biggest energy use in this state, and since much of the rain runs off and use keeps increasing, our ground water is still being depleted. Before you start irrigating, dig down a few inches and check out the soil. I was preparing a spot this afternoon and my soil was still very moist under the surface. It will be a while before I need to do any more than sprinkle new seedlings and water containers, which do dry out quickly in the wind.

 Some pest and disease issues increase with late rains. I’ve seen lots of disease on peach and nectarine trees - both peach leaf curl and the die back of flowers and new shoots that is indicative of brown rot. Although peach leaf curl can look bad, it usually does not do significant harm to the tree or crop. Often the affected leaves drop and more healthy leaves emerge in a few weeks. If all the leaves drop and even the second leaves are badly affected, then it can be a real problem requiring dormant sprays late fall and winter. Make sure the trees are in full sun with good air circulation and are well pruned too. Peaches and nectarines need a lot of pruning! Brown rot is a much bigger problem. This fungus disease can enter the tree at bloom and sit dormant in the developing fruit, waiting to increase rapidly as fruit ripens. This is what causes fruit to rot before becoming completely ripe, and can make an entire crop unusable. This disease is hard to control, but destroying all affected fruit promptly is essential, as are the good cultural techniques mentioned above, along with good soil fertility and appropriate irrigation. Aphids love the tender, juicy new growth now too. Plums and roses can be particularly hard hit. Keep a close eye on these; in a healthy, diverse garden nature’s controls will come to the rescue in the form of lady bugs, predatory wasps, and even the otherwise dreaded earwigs eating the aphids. If aphids seem to be doing real harm, you can rub them off, use a strong spray with a spritz bottle or hose, or a mild soap (not detergent) spray.  

 As for planting now, no guarantees but we are probably past the last frost, so if your soil is warm and dry enough to prepare, go for it with warm season crops! More on getting these off to a good start next time.

 Happy gardening!

Wendy