It's Getting Chilly. Is Your Garden Ready?

 The typical Sacramento-area frost season (when temperatures dip to 32 or below for short periods of time) is fairly short: primarily, December and January.

However, November frosts do happen here with regularity. Freezes, too.

The earliest frost date for Sacramento was on a November 4, back in 1935, when the morning low fell to 30 degrees. The latest frost date recorded was on March 27, 1898, with a low of 32.

Last year, there was a 2010 Thanksgiving surprise: the morning low temperatures in the suburbs of Sacramento dipped into freezing territory. 28 in Elk Grove. 24 in Rancho Cordova. 23 in Folsom. The temperatures in Rancho Cordova and Folsom stayed below 28 degrees for 7 hours that morning. That's a hard, citrus-killing, perennial-punching freeze.

Freeze-Pummelled Pummelo

Not a Happy Hosta Thanksgiving

What is cold? Some definitions:

Frost: temperatures dip to 32 °F (0 °C) for short periods of time. Occurs with fair skies and light winds.

Freeze: temperatures at or below 32 °F

Hard Freeze: temperatures below 28 °F for several hours.

 Fruit-laden citrus trees could be threatened by very cold mornings in the weeks (or days) ahead. Some planning tips for the upcoming cold mornings:


Before a frost:

• Identify cold spots in landscape by monitoring with a thermometer that registers high and low temperatures.

• Identify plants at risk: citrus, succulents, tender perennials, tropical and subtropical plants.

• Have supplies ready: sheets or frost cloths, lights, wraps for trunks, thermometers, stakes or framework to hold covers off foliage.

• Prepare tender plants: avoid fertilizing and pruning after August to minimize tender new growth. 

• Plant insurance: In September and October, take cuttings from frost sensitive perennials; keep cuttings in a sunny, indoor area.

• Rake away mulch to allow soil to warm up during the day and radiate heat at night into plant.

• Monitor weather forecasts and note how low temperatures will be and for how long. 

Pipe Wrap: Cheap Frost Insurance

When a frost is forecast:

1. Move potted plants to a warmer spot next to house or under patio cover, especially on south side.

 2. Check that plants are well-watered since dry plants are more susceptible to damage, and moist soil retains heat better than dry soil.

3. Cover plants with a row cover before sunset to capture ground heat radiating upward at night, but remove covers daily if it is sunny and above freezing to allow soil to absorb heat.

4. Add heat by using outdoor lights: hang 100 watt drop lights or Holiday string lights to interior of plant. Use the old C7 or C9 large bulbs, not new LED lights which do not give off heat.

5. Wrap trunks of tender trees if hard freeze is expected, using towels, blankets, rags, or pipe insulation.

6. Harvest ripe citrus fruit. Generally, both green and ripe fruit are damaged below 30 degrees, but there is some variation by species (refer to the chart in UC/ANR Publication 8100, "Frost Protection for Citrus and Other Subtropicals").

7. Winterize your gasoline-powered garden equipment. Gas can go bad and screw up your engines if allowed to overwinter, unused. Drain the tanks or turn off the supply valve and run the engine until it stops. For containerized gas (or gas still in equipment) add a stabilizer. Run the engine for 10 minutes or so to make sure the stabilized gas is thoroughly mixed into the engine.

When a Freeze or Hard Freeze is Forecast (temperatures remain at or below 28 degrees for several hours)

  1. Wrap any exposed plastic water pipes; cover outdoor faucets, as well. Turn off the water supply to outdoor irrigation faucets, if possible. Allow those faucets to drain.

 





2. Disconnect garden hoses and lay them out straight...away from driveways!


3. Adjust your pool, spa or pond filtration timers so that they are running when the chance of freezing temperatures is greatest, between two and nine a.m. Moving water is less susceptible to freezing.

4. For dish-shaped fountains: Turn off and let drain to the holding tank below ground. Remove any standing water in the dish.

Frosty the Fuchsia

After a frost:

1. Identify damage: dark brown or black leaves and twigs.

2. Wait to prune out damage until after danger of frost is past, and new growth begins in spring.

3. Make sure the backyard birdbath isn't frozen over in the morning. Daily fresh water for dogs and cats is also a good morning habit.

Is Your Garden Storm-Ready?

The folks at the Dirt Du Jour page remind us here in Northern California that it's time to prep the garden for the first big storm of 2011. And the National Weather Service, along with their highly-caffeinated, ALL CAPS style, chime in:



...WINTER-LIKE WEATHER SYSTEM TO BRING WET AND BREEZY WEATHER MID
WEEK...

A STRONG FOR THE SEASON COLD FRONT WILL MOVE THROUGH NORTHERN
CALIFORNIA LATE TONIGHT AND WEDNESDAY. THIS SYSTEM WILL SPREAD
PERIODS OF MODERATE TO HEAVY RAIN ACROSS THE REGION. EXPECT GUSTY
SOUTHERLY WINDS WITH TEMPERATURES DROPPING TO 15 TO 25 DEGREES
BELOW NORMAL.

* RAINFALL TOTALS ARE FORECAST TO RANGE FROM ONE QUARTER INCH TO THREE
  QUARTERS OF AN INCH OVER THE VALLEY AND ONE TO 2 INCHES OVER THE
  WEST SLOPE OF THE SIERRA NEVADA.

* WIND GUSTS OF 15 TO 30 MPH ARE EXPECTED IN THE VALLEY AND LOWER
  FOOTHILLS WITH GUSTS OF 40 MPH OR HIGHER OVER HIGHER MOUNTAIN
  ELEVATIONS.

* ISOLATED THUNDERSTORMS ARE POSSIBLE WEDNESDAY AFTERNOON IN THE
  CENTRAL VALLEY.



And yes, we are weather weenies here in Northern California. Please bear with us as we...

Get Ready for the First Big Storm of Autumn!

A checklist:

Hey, It Works.

• Secure, cover or remove patio furniture, bbq.
 

• Remove pads and umbrellas.
• Add compost to garden bed. Let the rains move it downward.

• Move plant starts to a safe area.

Ugly, but functional.

• Add gutter extensions.
 

• To fertilize or not fertilize the lawn before a predicted rainstorm? Pros: fertilizer will be worked into the soil effortlessly. Cons: heavy rain could wash fertilizer off a lawn, especially if it is sloped, into the gutter. Synthetic chemicals in lawn fertilizers can damage creek life. Using organic fertilizer is one possible solution. Still, runoff from that can cause problems, as well. Do you feel lucky?

• Remove diseased, dying plants and fallen fruit. Rainfall can spread harmful fungal diseases.

• Low spots? Mark those overly wet areas with a stick and take action after the storm (see below for more).

• Turn off the automatic sprinklers. Reset after the storm or just water manually, as needed, between storms.

Keeps the Aphids Out, Too

• Protect new plants in the ground with row covers. Heavy rain could uproot seedlings. Row covers will disperse that action.

• Move tools indoors. Cover or move lawn mowers, tillers, etc.

• Turn over buckets, pots, etc. to keep mosquitoes from breeding.

• Do you use a sump pump during the winter to move water from unwanted areas, such as pool covers? Make sure it is working!

• The first storm of the season means downed tree limbs. 

• Does your generator work?

Do You Feel Lucky, Persimmons?

• Harvest heavy fruit (apples!) to keep branches from breaking. Pray for your unripe persimmons.

• Cover or move any harvested crops.

• Harvest whatever might rot from too much water, such as walnuts or popcorn.

• Do you have a covered area to feed outdoor pets?

• Do you have a shelter for your outdoor pets?

• Empty pool filters. The first batch of storm-driven leaves are on the way!

• Cover the pool and spa to keep debris out.
• Secure the spa cover. They will blow open!

• The combination of leaf-heavy trees and storms means a high possibility of large branches falling. Move your valuables out of harm's way, including your vehicles. 

Easy Entry for Possums!

• Replace torn tarps on firewood.

• Clean roof gutters before the storm.


 

For Overly Wet Areas After the Storm (and after the soil has dried a bit):
* Dig a sump. A hole that is dug in the lowest portion of your yard, a hole that penetrates through all the layers of hardpan (usually 2-4 feet below the surface), can help drain away stormwater. Line the hole with a non-porous material (hard plastic sheeting, for example) to keep the surrounding dirt from falling back into the hole. Fill the hole with small rocks, about one inch in diameter.

* If it's the lawn area that's flooding, dig a trench and lay a drain line in the lowest area of the lawn. Don't do any digging immediately after a heavy rain, though; wait until the soil dries enough to avoid unnecessary soil compaction. 

 Be sure to slope the drain pipe, allowing at least a one foot drop for each 100 feet of length (one quarter-inch per foot). Dig backwards from where the water will exit the pipe, trenching back towards the source of flooding to help determine how deep to lay the drain pipe. Line the trench with a few inches of gravel, both above and below the pipe. For a lawn area, try to lay the pipe at least two feet below the surface.

* If it's the garden bed that's flooding, consider building raised beds this fall, lining the bed with 2X8, 2X10 or 2X12 redwood planks. Capping off the top of these boards with 2X6 redwood will give you a comfortable place to sit while harvesting vegetables and pulling weeds.

* If you haven't planted in a flooded area yet, consider creating mounds first, planting trees and shrubs on the top of the mounds.

* If you're still stuck with pools of standing water after heavy rains despite your best efforts, consider planting trees and shrubs that can take "wet feet". Water-tolerant trees for our area include birch, sweet gum, magnolia, tupelo and coast redwoods. Shrubs for wet areas include thuja and red twig dogwood.