Watch out for the first freezes!
Cold weather is on the way, and the first freezing temperatures often happen in November in Portland. Those who live in outlying areas or higher elevations may have already experienced frost. Please see our December Tips page for several details about winterizing your yard and protecting your plants from cold damage.
November is usually the last chance of the season for any digging. If your soil is already saturated or frozen, it is not recommended. Assuming it is not, finish any planting of hardy plants or dividing of perennials. If you have vegetable or annual beds that are empty, consider a cover crop or some mulch to protect the soil from compaction or erosion in rain.
Speaking of which, this is one of the best times for mulching. You can use bark, compost, leaves, or straw. This will help to protect the surface roots of your plants from freezing air and reduce weed growth. Compost is good for soil health, but only helps so much with weeds. Bark is very good for weed control, but avoid turning uncomposted bark into your soil (now or in spring) as it can limit the nitrogen that is available to your plants for some time. One to two inches of mulch is generally sufficient, and more than that is not better. Never place mulch so that it is touching the wooden stems of shrubs or trees.
Portlanders are lucky to live in a city with so much green space. Our combination of rivers, parks and mild climate allows Portland to host a vast array of birds and wildlife.
Birds are attracted to areas where the three basic needs of Cover, Food and Water are met.
The season is winding down, but your containers and window boxes don’t have to look like it. Clean out the dead or dying annuals and replace with cold season options. Pansies, dusty miller, kale, and many herbs look great as we enter the cold season. Miniature conifers and spring flowering bulbs are also great additions.
As stated before, this is probably your last good chance for any perennial planting and dividing. Hellebore, heuchera, and rosemary usually continue to look great if you still need additions. Lift, clean, and store your dahlias and begonias that grow from tubers. Our dahlia feature page has good instructions for this. Mulch those perennials!
Many deciduous trees prefer to be pruned in late autumn or winter. Our December Tips page has a listing of examples. Note that cherries and plums should be pruned in summer to avoid disease considerations. If you are unfamiliar with proper pruning techniques, consult our pruning page.
Dormant spraying can start in November. This means the application of particular pesticides while the plant is dormant. While many gardeners wait until February before spraying, multiple applications throughout the winter can benefit those plants with significant problems. Disease-prone fruit trees, roses, and lilacs often benefit from dormant spraying. If you have had disease problems with these or other trees and shrubs, then feel free to inquire with us about what can be done to help. Overwintering insect eggs can sometimes be controlled with other, oil-based dormant sprays.
Please note that while the products we have for dormant spraying are accepted for organic gardening practices, they can be dangerous to the applicator if misused. Always follow label precautions.
Many indoor flowers can help to beautify this time of year. Paperwhites and amaryllis are great bulbs for forcing indoors, and poinsettias, holiday cacti, and other gift plants are available.
You may be bringing some tender plants back inside about now. Don’t wait until freezing conditions! Check these plants for insect infestations, especially on plants such as hibiscus, abutilon, and gardenias. Your plants may shed some leaves as they get used to lower light levels indoors. Don’t panic too much, just provide as much light as possible, consider supplementary grow lights, and try to be a moderate waterer.
It is too late for fertilizing your lawn and probably too late for seeding. If the weather is not too cold, sod installation may still be an option. Remove excess leaves from your lawn and use them as mulch or discard them.
The only green vegetable that should be planted this late is kale. Existing cole crops (broccoli, cabbage, etc.) and lettuce or other greens can be protected with frost blanket or in a cold frame. If possible, harvest what you can before a hard freeze (significantly below freezing) and enjoy. Last chance for autumn planting of garlic and onions for harvesting next year.
Visit individual month pages for gardening ideas. Pages are regularly updated with projects for that month.