Gardening
for Your Watershed – October 2003
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This month’s
topics:
* Putting Your Garden to Bed
* Pest of the Month: Spruce Aphids
* General Gardening Tips
Starting next month, this newsletter will go onto a bi-monthly schedule until the spring.
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Putting Your Garden to Bed
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With the stormy weather, probably the last thing you want to do is tend to your garden. But prepping your garden now can really pay off in the spring. Here are a few tips to boost your plants’ health and cut down on next season’s pests and diseases:
- Rake up
leaves and twigs. Getting plant debris out of your beds will eliminate
many
overwintering spots for pests. And raking up tree
leaves from your lawn, before they become a soggy mat, will help
to keep your turf healthier.
- Cut back perennials and pull up annuals. Same reasoning here—clear
out the litter that pests like to hide in. Avoid putting diseased plants
or leaves in your compost pile.
- Pick up pots,
old boards, and other debris. Slugs love to lay their eggs under this
kind of cover.
- After raking
your lawn, overseed it. A thicker lawn is more able to crowd out weeds
and withstand other damage.
- Mulch your plants. You can use dairy compost (or any kind of
compost, for that matter), shredded leaves, or straw. This will help
protect your plants’ roots, smother weeds, and add nutrients as
they break down over the winter.
- Test your soil’s acidity and add lime to “sweeten” it, if necessary. Soils tend to be acidic in western Washington, and lime will help make them more neutral. If you add lime, do it about every other year or every third year for heavy soils. For every 100 square feet, use 4 pounds of lime on a sandy soil, 6 pounds on a loamy soil and 8 pounds on a clayey soil. Blend it into the top 8 - 10 inches of soil, preferably during a dry spell. It takes about three months for lime to alter soil chemistry, so a fall application is best.
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Pest of the Month: Spruce Aphids
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Wintertime is not usually a season that people think about pests. However, pests like spruce aphids are active and damaging trees at this time. Spruce aphids can seriously defoliate Sitka spruce (Picea sitchensis), Norway spruce (Picea abies), blue spruce (Picea pungens), and other ornamental and commercial spruces—to the point of killing the trees. Damage may also occur, although rarely, on other conifers such as pines (Pinus spp.) and Douglas-fir (Pseudotsuga menziesii).
Beginning in October and November, aphids start to resume their defoliating ways. At this time, turn a watchful eye on the activities of these aphids. If you experienced severe infestations this past year, monitor your aphid populations closely throughout next winter and spring.
To check your trees for aphids, try using a beating tray. This tray is a simple white canvas square supported by PVC tubes. A stiff piece of white cardstock works just fine, too. Hold the cardstock under the tree and brush or knock two branches together to jar the aphids off the spruce needles and onto your card. Be sure to sample the new growth of the tree branch; this is where the aphids will be.
Count the number of aphids that land on your card. Look closely because these aphids are small! Record the number in a notebook. Do this regularly and look for increases in the numbers of aphids as time goes by.
Decision-making:
-
If aphid numbers do not change much and you see little damage, you probably
don’t have to do anything.
- If aphids
build rapidly but the freezing weather is just around the corner, continue
monitoring and bet that the cold freeze with reduce
the population. Keep weather as a factor when you are deciding on your
management.
- If aphid
populations are high this fall, begin to use the water hose and regularly
blast them out of the tree to reduce the population
size.
- If populations rapidly increase towards the end of winter, consider using an insecticide. Go to Hortsense (http://pep.wsu.edu/hortsense) or refer to the PNW Insect Management Handbook (http://pnwpest.org/pnw/insects) for pesticide recommendations. Be sure to read the label and follow directions.
For more information on spruce aphids, read the June 2003 issue of WSU’s Agrichemical and Environmental News.
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General gardening tips from WSU Master Gardeners
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* Plant spring bulbs by Thanksgiving, as they need 12 weeks in cold ground before they bloom.
* If you have mums this fall, you can turn your small investment into a half-dozen new mums next spring. Should you choose to save your mum, plant it this fall in a sunny well-drained spot with moist, fertile soil. Next spring, just as the mum’s new growth starts, dig it up and use a sharp shovel to cut the root ball into six equal pieces, each with a bit of stem and root. Replant the pieces in your garden, and give them a drink of water. They should do just fine.
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This newsletter
is produced by Whatcom County Extension. To subscribe or unsubscribe,
or to make comments and suggestions, please contact Scarlet
Tang or
360/676-6736.
