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.

Brown Lawn? Renovation Time is Coming!

In the city of Sacramento, as in many other locales, watering a lawn every day is no longer an option. Ordinances throughout California mandate a maximum of three days a week for landscape irrigation.

And the response by some homeowners?  "If I don't water my lawn every day, it turns brown!" I hear this far too often from listeners on my garden radio shows.

There are a lot of possible culprits for this scenario: compacted or poor soil, slow drainage, the wrong turf type for the area, sloping lawns, uneven coverage by sprinklers and more. 

The biggest culprit in lawn problems? Watering a lawn every day. Daily, light irrigations causes lawn roots to remain near the surface, where they are more susceptible to damage from heat, cold, animals, disease, etc.

And those lawn roots may not be getting much water, because of thatch buildup.
 
According to the UC Guide to Healthy Lawns, thatch is the layer of living and dead stems, roots, stolons, and rhizomes between the green blades of grass and the soil surface. A thin layer of thatch (less than 1/2 inch thick) can be beneficial to the lawn because it helps to limit weed germination, reduce water evaporation, and protect from frost damage. However, thick thatch layers can prevent water, air, and nutrients from penetrating the soil, causing reduced root growth and increased potential for drought stress. Thatch also favors fungal growth and can harbor insect pests. Some turfgrass species, such as bermudagrass, bentgrass, and Kentucky bluegrass, have creeping growth habits and rapidly build thick thatch layers. But even the popular fescue varieties of lawn can build up a thick layer of thatch, even though the grass is green on the surface.

If you haven't dethatched your lawn in three years or more, September through mid-October is the time to not only dethatch, but to also aerate, fertilize and overseed your lawn.
 
If more than 40% of your lawn is in really bad shape, then consider a complete lawn renovation in September or early October here in the mild winter areas of California. In other parts of the country, spring is the best time for this makeover. A complete lawn renovation involves removing all the existing turf, improving the soil and reconfiguring the sprinkler system to better cover the entire area, as well as choosing the right turf type for your area. Directions for a complete renovation can be found here.
 
A partial lawn renovation involves uprooting thatch, aerating the soil, overseeding the lawn area and applying a thin layer mulch to maintain a healthy lawn throughout the coming year.
     
The first step is to cut your lawn as short as possible. Then, water your lawn thoroughly to soften the soil. Wait a day or two. Then bring on the necessary components: a dethatcher, aerator, starter fertilizer, compost for mulch, lawn seed, drinks and snacks. After all, if you've worked in the yard all day, who'll have the energy to run to the store for refreshments?
         

The dethatcher can be as simple as an iron rake or as complex as a power dethatcher or vertical mower, available at rental yards. Thatch - layers of dead grass - impede the movement of water and fertilizers to the root zone of a lawn and should be removed every two or three years. 

During the dethatching process, you may be in for a rude awakening.  See that pile of thatch? It's about two cubic yards. That's what we removed from about 4000 square feet of what looked to be an otherwise healthy lawn. You can't see thatch when it's just below the lawn's surface!

After dethatching, remove the dead grass and then aerate the lawn area. An aerator, a device with sharp, hollow tubes, removes soil cores that are three to four inches deep. Aeration relieves soil compaction, allowing air, water and fertilizer to pass more freely through the soil, stimulating root growth. Hand aerators are available, but rented roller or power-driven aerifiers do the job more quickly and effectively, albeit more expensively.

         



Then, spread starter fertilizer and a lawn seed that closely matches your existing grass over the area. However, for Bermudagrass lawns, overseed with an annual or perennial ryegrass; this will keep your lawn green during the winter and spring while the Bermuda grass is brown and dormant. 

After overseeding, press the seed into the ground with a water-filled roller, or rake the seed lightly to make sure it is in contact with the soil. Finish up by spreading a thin layer of compost over the entire area.


Keep the reseeded lawn area moist; the new seeds will sprout in seven to ten days. This is the ONLY time you need to water a lawn every day, keeping the seedbed evenly moist until the grass is up and growing. Then, set your sprinklers to come on for a period of time that's appropriate for the weather: two or three times a week during the hottest months; once a week during the cooler months when it doesn't rain. And turn off the system entirely during the rainy season.
         

After dethatching, aerating and overseeding, your lawn will look absolutely terrible. Do not fear.  

 By Thanksgiving, you will have the greenest lawn on the block!