Garden Tasks To Do, and NOT Do, This Fall

Columbus Day, Halloween, Veterans Day, Thanksgiving, Hanukkah, Christmas. The busy holiday season awaits. OK, maybe you aren't going to get dressed up as the "Santa Maria" and march down Main Street on October 8, but there are still enough other tasks to accomplish this time of year to dissuade you from the garden. The good news: here are some yard chores you don't have to tackle this time of year.

• Don't deadhead your roses. Many Northern California rosarians are now advising rose growers to let those fading October flowers remain on the plant. This will force the rose bush to form hips, which helps the plant slow down in preparation for the January pruning season. Because cold winters are not a certainty here, roses have problems entering complete dormancy in our area. Not pruning roses now tells the plant, "Time to take a nap!"

• Don't prune your shade trees until the last leaf has fallen. Then, it will be easier to gaze up into the canopy of the tree to decide which branches need to be trimmed or removed. Good reasons for pruning trees include removing or cutting back branches that are rubbing each other or the house. Low branches that impede foot traffic or suckers emanating from the base can be removed at that time, too. If you think you won't remember the dead branches that will need to be removed when all the leaves are gone, go ahead and mark those branches now with ribbon or green tree tape.

• Don't Prune Citrus Trees. Lance Walheim, author of the books "Citrus" and "All About Citrus & Subtropical Fruits", says early fall is the one season to avoid taking a saw to your orange, lemon, mandarin and other citrus trees. The soil is still warm, which will push out new growth wherever you made a pruning cut. And that new growth will be more susceptible to frost damage during the late fall and winter.

• Don't Prune Apricot and Cherry Trees. Apricots and cherries are susceptible to Eutypa dieback, a disease which kills branches. Infection occurs on wounds made during wet weather. You need six weeks of dry weather after pruning. Prune these trees after harvest in late spring or early summer.

 

And now, for you masochists, some autumn garden tasks to add to that growing list on the side of the refrigerator.

• Clean up the summer vegetable garden. Many garden pests overwinter in fallen fruit and twigs, too.

• After you've cleared out the dying summer vegetables, prepare for next year's garden by checking the soil pH. Test kits are available at just about every nursery.

  •  Tomato hornworms are going into hibernation in the soil beneath your tomato plants. Dig down about four inches and discard their cocoons, which resemble two inch-long, reddish footballs.

• Feed your bare garden soil during the winter with a cover crop of clover, fava beans or vetch. This will add nitrogen for next year. 

Chinese Pistache

 • This is a great time for planting new trees and shrubs, especially ones with outstanding fall foliage for California. Good specimens include Japanese maples, Chinese pistache, tupelo, red oak and scarlet oak.

  
• Vegetables to plant from seed now include radish, spinach, fava beans, carrots, swiss chard, corn salad, leaf lettuce, onions and peas.

•  Despite the cooler temperatures, your lawn and garden still need about an inch of water a week. Unless the rains come, keep your automatic sprinklers operating. How much water is an inch? Here’s how to measure.

•  Cool season lawns, such as the popular fescue blends, are putting on a spurt of growth now. Mow often so that you are never removing more than a third of the total height of the grass blade.

 • Dethatch, aerate and overseed bermuda grass lawns with rye grass to keep it green all winter. At a loss of how to start? Here’s how.

•  This is a good time to plant ground covers such as low growing manzanitas, verbena and carpet bugle. This will give their root systems a chance to get established for their burst of spring growth.

• Scatter and plant tulip and daffodil bulbs outdoors for a more natural look.

• Add some indoor color for the upcoming holiday seasons by planting bulbs in containers. Your favorite local nursery has a good supply right now.

• Feed and protect rhododendron and azalea roots during the winter by adding two or three inches of mulch around those plants. More on the benefits of mulch.

• Available now at nurseries: colorful winter blooming annuals such as violas, calendulas, stock, Iceland poppies and snapdragons.

 • Temperatures dipping down below freezing can occur in many of the interior areas of Northern and Central California in early November. Prepare for that possibility by moving frost-sensitive potted plants indoors or against a west or south-facing wall.

  

• Row covers, hot caps, and water-filled containers surrounding young vegetable seedlings offer these plants a warmer nighttime environment.

 

• Prepare for the rainy season by knocking down watering basins around trees.

Tomatoes Love Basil...Or Do They? Ask the Snarky Farmer!

 It smells like Friday.  Time to...Ask the Snarky Farmer!

Paul in Sacramento writes: 

"I have a conjecture that I need to have validated, or otherwise. Could it be that the proximity of my basil plants to the tomato plants has anything to do with the lack of tomato hornworms? The vapors from the basil are wonderfully aromatic. Have I, in any way, gotten something right without even trying?"

 

Paul:
Here is a link to a rather lengthy, scholarly paper from West Virginia University on the subject of companion planting, including the relationship of tomatoes and basil.

To sum up the research briefly: No, Paul, you haven't, at least not in the way you intended. But you may have encouraged the tomato plants to grow stronger.


The longer answer,  from that PhD dissertation:   
"The earlier data showed that there is no scientific evidence that the odors from highly aromatic plants can actually deter pest insects. This, therefore, brings into question how these aromatic plants produce their effects. The studies reported here showed the relationship of tomato to basil to be one of domination, with a net benefit accruing to the gardener from basil’s ability to survive and produce some yield without compromising tomato yield. Although companion planting has significant effects on some insect pests at the garden scale, these effects are not simply due to the combination of certain companion species. High density plantings can optimize land use efficiency and diculture advantages, but may lead to reductions in crop quality, or management difficulties. The combination of a dominant and subordinate crop results in larger dominant plants and smaller subordinate plants than in equivalent monocultures grown at the same density. Such combinations offer yield advantages when the increase in dominant plant weights exceeds the reduction in subordinate plant weights, suggesting that the two crops draw on slightly different resource sets. Combinations with high subordinate crop proportions may offer the greatest yield advantages."

Another interesting facet of that study asks the question that many gardeners assume as gospel: 
Do tomatoes, when planted with basil, taste better?

If you are squinting to try to figure out that chart, allow me to interpret the results of that test: there is little, if any taste difference. 


But Paul, you still are asking a good question. Where did the tomato hornworms go? I have heard from many gardeners that hornworms just aren't the problem they used to be. Again, that study hints at a possible reason:

"Ground beetles and harvest spiders prey on caterpillars at a higher rate in polycultures" (Dempster and Coaker 1974).

 Because of shrinking yard size and the influence of such books as Mel Bartholomew's "Square Foot Gardening", more and more backyard gardeners are cramming lots of different vegetables together in a planting bed: a polyculture.


And yet another "garden good guy" (although many think ill of this creature), the European paper wasp, is at work on hornworms, according to Dr. Whitney Crenshaw of Colorado State University:

"The European paper wasp has been huge out here in recent years. It took over in a phenomenally short period of time. In addition to the stinging/nuisance issues (complicated by its very close superficial similarity to the western yellowjacket), the insect has decimated backyard Lepidoptera. It has had such an impact that I no longer discuss cabbageworms or hornworms in Master Gardener programs – they are too rare. Also, I usually drop butterfly gardening as a topic, as they eat the butterfly larvae."


And don't forget the help tomato growers get from the ubiquitous (and hungry) backyard birds. Build it (a bird-friendly garden), and they will come. So what if you lose a few tomatoes along with the worms?