Saturday, October 31, 2009

Cold Weather Houseplant Care


As the weather turns cooler, we begin to pay more attention to horticultural chores in the great indoors. Houseplants need a bit of TLC right now, as they adjust to the change of seasons. Houseplants tend to slow down their growth cycles now, so their food and water requirements are less.

        Many houseplant aficionados won't even feed their houseplants now, and won't resume a monthly fertilization until next spring. And because houseplants use less water now, change your irrigation habits. 

     Poke your finger or a moisture meter into the soil of a houseplant to make sure that the top few inches have dried before you add water. Another way to determine if your houseplant is in need of water: lift the pot. If it is as heavy as it was when you last watered, wait. When the soil has dried, that pot will be a lot lighter, a good sign that it's time to pour it on.

        During fall and winter, the sun is lower in the horizon. Help your houseplants cope with this lower level of light by moving them a bit closer to a sunnier window.

        There are some indoor plant pests that may be moving into your house this time of year. Aphids, spider mites, whiteflies, fungus gnats and scale are among the pests that are taking up residence with you, especially if your houseplants have spent any time recently outdoors or are new purchases. A couple of good books about houseplants, including lots of pictures of plants and pests, are "The Complete Houseplant Survival Manual" by Barbara Pleasant and "Successful Houseplants" by Ortho Books.

        And one reader is wondering about how to control another common houseplant pest. From the garden e-mail bag, Cynthia writes: "I have an indoor coleus plant in my bathroom, which gets indirect sunlight. All was well until yesterday when I discovered little oblong or rectangular-shaped, white, fluffy somethings on the plant. What are they and how do I eradicate them?"

     Those "fluffy somethings" might be mealybugs. These soft-bodied sucking insects are about one-eighth of an inch long, and are covered with a whitish, cottony wax. They especially like to congregate on the backsides of the leaves of houseplants, where the leaves meet the stems.

        There are several steps you can take to control mealybug populations on your houseplants. Step One: wash off the plant, especially the underside of the leaves, in the sink with a forceful stream of lukewarm water. Doing this once or twice a week for a few weeks may take care of the problem. Step Two: Dip a cotton swab in rubbing alcohol and remove the mealybugs by hand. Tweezers can help dislodge the ones you can't reach  with a cotton swab. If those two techniques don't do the job, apply insecticidal soap or a narrow-range horticultural oil to the infested plant area. But be careful: make sure your plant won't be damaged by the soap or the oil by testing it on a small, out-of-the-way part of the plant first. According to Lori Ann Asmus of Emerald City Interior Landscape Services in Sacramento, scrape away and replace the top inch of soil in the potted plant. That can help eliminate future mealybug populations.

Thursday, October 29, 2009

What NOT To Do in the Garden Now

     In the interest of easing your garden workload as the busy holiday season approaches, here are some yard tasks 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.

Wednesday, October 14, 2009

After the Storm: Inspect Your Trees!

      The day after a major rain and wind storm is not necessarily the best day for the backyard gardener to tackle the hazardous task of cleaning up the remnants of trees, shrubs and other plants that took a beating. If wind and rain is still in the forecast, the prevalence of slippery conditions and the chance of more falling debris should limit your cleaning chores to dragging broken branches away from the scene of the crime. It is not a good day to be climbing ladders or scrambling into trees while balancing a chain saw. Leave that to the professionals. 

     Sacramento-based arborist Analisa Stewart of Arbor Entities offers this good piece of advice for those surveying the fallen aftermath of a major storm: "Limb failure is largely a product of poor tree maintenance over time," says Stewart. "Take care of your trees, or they may take care of themselves in ways you won't appreciate."
     According to the University of California publication, "Inspect Your Landscape Trees for Hazards", a nice day in autumn (or winter, spring or summer, for that matter) is the time to take an inventory of any possible future tree damage before you, your house or your car becomes the next victim of a falling tree or branch.

Leaning Trees: Are your trees not as upright as the result of recent heavy winds? Can you see newly upheaved roots or soil around those trees? Then, immediate action is required: call in a professional, certified, bonded and insured arborist to do an onsite inspection and offer a solution. Newly leaning trees are an imminent hazard. If you have a tree that has leaned for a number of years, that tree can still be a hazard during wet, windy weather. Taking periodic photographs can help you determine if a greater lean is developing.

Multiple Trunked Trees: This co-dominant condition can result in breakage of major tree parts during storms. Usually, these trunks are weakly attached. Inspect the point where the two trunks meet; if you see splitting beginning, call in an arborist.

Weakly Attached Branches:
Trees with many branches arising from the same point on the trunk are prone to breaking during wind storms. Prune out any split branches. Thin out multiple branches.

Hanging or Broken Branches: If you see storm damaged branches hanging from the tree, remove them as soon as possible. This includes removing any completely broken branches that may be resting elsewhere in the tree's canopy.

Cracks in Trunks and Branches: Measure the depth of any cracks with a ruler. If those cracks are more than three inches deep, call in an arborist to determine the best course of action.

Dead Branches: Branches that have completely died are very likely to fall off in a storm. Dead branches are most noticeable in the summer when the tree is in full leaf.

Cavities and Decay: Large, open pockets where branches meet the trunk, or at the base of the trunk, can mean big trouble. The presence of mushrooms on the bark or on exposed roots may indicate wood decay. Call in an arborist.

The Arbor Day Foundation website has this animated guide to proper pruning techniques.

Tips for Hiring an Arborist.

Friday, October 9, 2009

Before the Big Rain & Wind Storm Hits...

 The National Weather Service is ringing the meteorological alarm bell for Monday through Wednesday, Oct. 12-14: lots of rain (2 to 7 inches), lots of wind (gusts to 50-60 mph). 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:

• 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.

• 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.

• 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.

• Turn over buckets, pots, etc. to keep mosquitoes away.
• 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?

• Harvest heavy fruit to keep branches from breaking.
• Harvest whatever might rot from too much water, such as walnuts.
• 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.

• 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. 

• Replace torn tarps on firewood.

• Clean roof gutters before the storm


For Overly Wet Areas After the Storm:
* 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 perforated 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.