http://extension.oregonstate.edu/linn JULYAUGUST 2024 7
Recommendations are not necessarily applicable to all
areas of Oregon. For more information, contact your local
Extension office.
e Oregon State University Extension Service
encourages sustainable gardening practices.
We emphasize preventive pest management over reactive
pest control. Identify and monitor problems before acting
and opt for the least toxic approach that will remedy
the problem. Favor biological control agents (predators,
parasitoids) over chemical controls.
JULY
Maintenance and cleanup
• Ifyouwantagreenlawn,waterfrequentlyduringperiods
of heat and drought stress. Irrigate a quarter inch four to
six times per week from June through August. Measure
your water use by placing an empty tuna can where your
irrigation water lands.
• Moundsoiluparoundthebaseofyourpotatoplants.
Gather and eat a few “new” potatoes from each hill when
plants begin to flower.
• Toreduceevaporation,watervegetableandower
gardens in the early morning. Water the soil rather than
leaves to reduce disease. Water deeply and infrequently to
encourage root growth.
• Paycarefulattentiontowateringandfeedinghanging
baskets of flowers or vegetable plantings during extended
periods of hot weather.
• Weedandfertilizerhubarbandasparagusbeds.Amulch
of compost or rotted cow manure works well as fertilizer.
Water deeply to develop crowns for next year.
• Mulchwithpaper,plastic,sawdust,etc.toconservesoil
moisture.
• Staketall-growingoweringplantssuchasdelphinium,
hollyhocks, and lupine. Stake tomatoes as necessary.
• Makecompostoflawnclippingsandgardenplantsthat
are ready to be recycled. Do not use clippings if lawn has
been treated with herbicide, including “weed-and-feed”
products. Do not compost diseased plants unless you
are using the “hot compost” method (120 degrees to 150
degrees F).
Planting and propagation
• Beets,bushbeans,carrots,cauliower,broccoli,lettuce,
kale and peas planted in midsummer provide fall and
winter crops. Get more tips on what to plant now in Fall
and Winter Vegetable Gardening in the Pacific Northwest.
• Digspringbulbswhentopshavedieddown;divideand
store or replant.
Pest monitoring and management
Use chemical controls only when necessary and only after
thoroughly reading the pesticide label. Consider cultural
controls first, then physical and biological controls. Choose
the least-toxic options (insecticidal soaps, horticultural oils,
botanical insecticides, and organic and synthetic pesticides),
and use them judiciously.
• Controlhollyhockrustbysanitation,pickingaffected
leaves, or spraying with a registered fungicide. Read and
follow label directions.
• Watchforcutwormdamageingarden.InJuly,climbing
cutworms become a problem and large portions of
foliage will begin to disappear on established plants. Use
barriers, remove by hand, use beneficial nematodes when
soil temperature is above 55 degrees F, or spray with Bt-k
according to label directions.
• LateJuly:Begintomonitorforearlyandlateblighton
tomatoes. Correct by pruning for air circulation, picking
off affected leaves, and/or treat with approved fungicide.
See this article for more information on common tomato
problems.
• Placetrapstocatchadultapplemaggoties.Youcanuse
pheromone traps to monitor presence of pests.
• July10:Spraylberttreesforlbertworm,asnecessary.
• July10-15:Spraypeachandprunetreesforpeachtree
borer and peach twig borer, as necessary.
• July17-23:irdsprayforcodlingmothinappleandpear
trees, as necessary.
• Coverblueberrybusheswithnettingtokeepbirdsfrom
eating the entire crop.
• Monitorcamellias,hollyandmapletreesforscaleinsects.
Treat if necessary.
• Monitorrhododendronsforadultrootweevils.Look
for fresh evidence of feeding (notching). Try sticky
trap products on plant trunks to trap adult weevils.
Manage root weevils with beneficial nematodes (if soil
temperature is above 55 degrees F). If root weevils are
a consistent problem, consider removing plants and
choosing resistant varieties.
• Spidermitescanbecomeaproblemonornamental
plants, vegetables and fruit plants during hot, dry
weather. Watch for dusty-looking foliage, loss of color
and the presence of tiny mites. Wash infested areas with
water or spray with appropriate pesticides. For more
information visit the PNW Insect Management Handbook
Landscape Pests - Spider Mites.
• Continuemonitoringraspberry,blackberry,blueberry,
cherry and other plants that produce soft fruits and
berries for spotted wing drosophila. If the flies are
present, use an integrated and least-toxic approach to
manage the pests. Learn how to monitor for drosophila
flies and larval infestations in fruit.
• Checkleafyvegetablesforcaterpillars.Remove
caterpillars as they appear. Use Bt-k, if necessary.
• Removecankeredlimbsfromfruitandnuttreesfor
control of diseases such as apple anthracnose and
bacterial canker of stone fruit. Sterilize tools before each
new cut.
AUGUST
Planning
• eoptimaltimeforestablishinganewlawnisAugust
through mid-September.
• Dampwoodtermitesbeginyinglatethismonth.Make
sure your home is free of wet wood or places where wood
and soil are in contact.
Maintenance and clean up
• Makecompostoutoflawnclippingsandgardenplants
that are ready to be recycled. Don’t use clippings if the
lawn has been treated with herbicide, including “weed-
and-feed” products. Don’t compost diseased plants unless
you are using the “hot compost” method (120 degrees to
150 degrees Fahrenheit).
• Fertilizecucumbers,summersquashandbroccolito
maintain production while you continue harvesting.
• Cleanandfertilizestrawberrybeds.
• Usemulchtoprotectornamentalsandgardenplantsfrom
hot weather damage. If needed, provide temporary shade,
especially for recent plantings.
• Camelliasneeddeepwateringtodevelopowerbudsfor
next spring.
• Pruneraspberries,boysenberriesandothercaneberries
after harvest. Check raspberries for holes made by crown
borers, near the soil line, at the base of the plant. Remove
infested wood before adults emerge (approximately mid-
August).
• Monitorgardenirrigationcloselysocropsand
ornamentals don’t dry out.
• Ifyouwantyourlawntostaygreen,you’llhavetowater
frequently during periods of heat and drought stress.
Irrigate 0.25 inches four to six times per week from June
through August. Measure your water use by placing an
empty tuna can where your irrigation water lands.
• Prunecherrytreesbeforefallrainsbegintoallow
callusing in dry weather. is will minimize the spread of
bacterial canker.
• WesternOregon:Pruneoutdeadfruitingcanesintrailing
blackberries and train new primocanes prior the to end of
the month.
Planting and Propagation
• Plantwintercovercropsinvacantspaceinthevegetable
garden
• Plantwinterkale,Brusselssprouts,turnips,parsnips,
parsley and Chinese cabbage.
• WesternOregon:Mid-summerplantingofpeas;use
enation-virus-resistant varieties. Plant fall crops of
cabbage, cauliflower and broccoli.
• Westernvalleys,Portland,Roseburg,Medford:Plant
cauliflower, broccoli, Brussels sprouts, spinach, turnips
and parsnips.
Pest monitoring and management
• Removecankeredlimbsfromfruitandnuttreesfor
control of diseases such as apple anthracnose and
bacterial canker of stone fruit. Sterilize tools before each
new cut.
• Checkapplemaggottraps;spraytreeifneeded.
• Controlyellowjacketsandwaspswithtrapsandluresas
necessary. Keep in mind they are beneficial insects and
help control pest insects in the home garden.
• Firstweek:Ifnecessary,sprayforwalnuthusky.
• Firstweek:Ifnecessary,secondsprayforpeachtree
borer and/or peach twig borer.
• Firstweek:Ifnecessary,secondsprayoflberttreesfor
filbertworm.
• Checkforrootweevilsinornamentalshrubsandowers;
codling moth and spider mite in apple trees; scale insects
in camellias, holly and maples. Treat as necessary.
• Watchforcornearwormonearlycorn.Treatasneeded.
• Formitecontrolonornamentalsandmostvegetables,
hose off foliage, spray with approved miticide if
necessary.
• Checkleafyvegetablesforcaterpillars.Pickoff
caterpillars as they appear. Use Bt-k, if necessary.
• Continuemonitoringpeaches,plums,prunes,gs,fall-
bearing raspberries and strawberries, and other plants
that produce soft fruits and berries for Spotted Wing
Drosophila. If SWD are present, use an integrated and
least toxic approach to manage the pests.
• WillametteValley:Cornmayneedprotectionfrom
earworm. Spray new silks with appropriate pesticides if
necessary.
• Coastalandwesternvalleys:Spraypotatoesandtomatoes
for early and late blight.
Trade-name products and services are mentioned as
illustrations only. is does not mean that the Oregon
State University Extension Service endorses these
products and services or intends to discriminate against
products and services not mentioned.
July-August Gardening Calendar for Western Oregon