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Order seed and set a starting schedule
Work backward from your average last frost. The March guide lists OSU's figures: Portland around March 21, Salem March 19, Seattle March 24, Olympia March 10. Inland valleys and higher sites are later. OSU Extension's January calendar puts planning and seed ordering at the top of the month's list.
- Onions and leeks: these are the slowest crops. Start them indoors in January or February for transplanting in spring.
- Broccoli, cabbage, cauliflower, early lettuce: start in late January to February for planting out under row cover in March, as the March guide describes.
- Peppers: start in early March. Tomatoes: start mid-March to April 1 (see the March guide). Tomatoes started in January get leggy long before west-side soil is warm enough to plant them.
- Choose short-season tomatoes and other varieties suited to cool PNW summers.
Give seedlings strong light. A bright window rarely provides enough in a gray PNW January.
When ordering, look for varieties bred or trialed for cool, short summers: short-season tomatoes, early sweet corn, and peppers that set fruit in cooler nights. Also look for disease resistance where it matters most west of the Cascades, such as powdery mildew on squash and peas and late blight on tomatoes. Check older seed for viability by rolling ten seeds in a damp paper towel for a week and counting how many sprout.
Dormant pruning: apples, pears and blueberries
Pome fruit and blueberries are pruned while dormant. Choose dry days so the cuts can dry out.
- Apples and pears: OSU Extension recommends late-winter pruning. Remove dead, diseased, crossing and water-sprout growth, and thin crowded branches to let light in. Disinfect tools between cuts on trees with fireblight, as the March guide describes, and finish by early March.
- Blueberries: per OSU Extension, prune highbush blueberries every winter for bigger, better harvests. Remove the oldest, least productive canes at the base, along with weak and low twiggy growth.
- Cherries, plums and other stone fruit: don't prune them in winter rain. OSU's bacterial canker guide links infection to wet-weather wounds.
How much to cut: on a mature apple or pear, thinning cuts that remove whole branches at their point of origin let light into the canopy without setting off the flush of water sprouts that heavy heading cuts cause. Avoid removing too much live wood in a single winter. Overpruning drives vigorous upright growth and fewer fruit buds. Neglected trees are best renovated gradually over a few winters.
Felco F-2 bypass pruners
Dormant pruning of apples, pears and blueberries starts this month, and clean, sharp bypass pruners make cuts that close faster and are easy to disinfect between trees. See how we chose it.
Fruit tree disease prevention
If you sprayed peaches and nectarines for leaf curl at leaf drop, the second spray goes on before buds swell. In mild west-side years that can be late January. WSU Extension and OSU Extension both treat this late-winter spray as essential. Spraying after the buds open doesn't work. Apply on a dry day, follow the label, and cover all twigs and buds.
Finish cleaning up mummified fruit and fallen leaves under apples, pears and blueberries if you didn't get to it in fall.
Take out cankered or dead branches on any fruit tree while you prune. On stone fruit, wait for dry weather before cutting. Remove tent caterpillar egg masses (shiny bands around small twigs) on fruit trees and ornamental cherries while the branches are bare and easy to see.
Check stored bulbs, tubers and produce
- Check stored dahlia tubers, gladiolus corms and tender bulbs. Throw out any that are soft or moldy. Lightly mist tubers that are shriveling.
- Sort stored winter squash, potatoes, onions and garlic, and use any that show soft spots first.
- For dahlias left in the ground (see the October guide), check that the mulch hasn't washed away and that water isn't pooling over the crowns.
Bare-root planting season
Late winter is when west-side nurseries stock bare-root fruit trees, roses, cane berries, strawberries and many shade trees. Bare-root plants cost less, and they establish well because their roots go straight into native soil.
- Plant as soon as you can after buying. Until then, keep the roots moist, either wrapped or temporarily covered with damp soil or sawdust in a shady spot.
- Soak the roots for a few hours before planting, and trim any broken ones.
- Dig a hole wide enough to spread the roots without bending them. Set the plant at the depth it grew in the nursery (look for the soil line on the stem). Keep the graft union of fruit trees above the soil.
- Don't plant into saturated soil. If the ground is too wet, heel the plants in temporarily and wait for a drier week.
Choose fruit varieties suited to west-side conditions, such as scab-resistant apples and peaches resistant to leaf curl. They make the disease calendar on this page much lighter.
Winter crops and cover crops
Kale, leeks, collards, chard and hardy greens keep giving small harvests during mild spells. Per WSU Extension, growth stays minimal until days lengthen. Pick lightly so plants have enough leaf area to push new growth in February and March. Keep row cover handy for cold snaps.
- Overwintering cauliflower, purple sprouting broccoli and spring cabbage are sizing up for late-winter and spring harvest. Keep slugs and weeds away from them.
- Garlic should have several leaves. Pull weeds by hand, and don't walk on the bed.
- Cover crops sown last fall are growing slowly. Leave them until a few weeks before spring planting. Per OSU Extension, they are protecting the soil from winter rain and, once they flower, feeding pollinators.
Soil, slugs and lawns in the wet season
January soil is usually too wet to work. OSU Extension's wet-soils guide explains why working saturated clay damages its structure for months. Spread compost on top of beds instead of digging it in, and plan raised beds for spots that stay waterlogged.
Slugs feed on any mild night. Per OSU Extension, spring is the next prime control window, but clearing hiding places around beds now gets you ahead of it. Lawns are best left alone this month. Moss is easy to see now, and WSU Extension explains that lasting control depends on fixing the conditions behind it.
East of the Cascades
East of the Cascades (zones 5–7), January is mid-winter and last frosts come weeks later than on the west side. Use a local schedule such as OSU Extension's Eastern Oregon seed-starting schedule, not west-side dates. Starting too early leaves you with overgrown transplants waiting for a May planting. January jobs here include ordering seed, checking stored produce and tubers, watering evergreens during dry thaws, and brushing heavy snow off shrubs. Fruit tree pruning usually waits until late winter, after the coldest weather.
Look for sunscald on the south and west sides of young, thin-barked trees, and for vole and rabbit damage where snow has drifted against trunks. Keep salt and salty snow away from beds and lawns. If the winter is snowless and dry, water evergreens and young trees on a mild day when the soil isn't frozen.
Common mistakes
| Mistake | Consequence | Correct approach |
|---|---|---|
| Starting tomatoes in January | Leggy, root-bound plants long before soil is warm | Start tomatoes mid-March to April 1 in the western lowlands |
| Pruning cherries and plums in winter rain | Bacterial canker enters through the cuts | Prune stone fruit in dry weather |
| Skipping the late-winter leaf curl spray | Leaf curl is set before leaves emerge | Spray before bud swell on a dry day |
| Digging or tilling wet soil | Compaction that lasts into the season | Top-dress with compost and wait for drier soil |
| Using west-side dates east of the Cascades | Transplants ready weeks before it is safe to plant | Use an east-side seed-starting schedule |
Frequently asked
When should I start seeds indoors in Portland or Seattle?
Onions and leeks in January or February, early brassicas and lettuce in late January to February, peppers in early March, and tomatoes from mid-March to April 1. Count back from a last frost around mid- to late March.
When do I prune blueberries in the Pacific Northwest?
During winter dormancy. OSU Extension recommends pruning highbush blueberries every winter, removing the oldest canes and weak growth before buds break.
Is January too early to prune apple trees?
No. Apples and pears are pruned while dormant. OSU recommends late winter. Pick dry days and finish before buds open in early March.
Sources
- January Garden Calendar (EM 9698), OSU Extension
- Prune apple trees in late winter for stronger growth and better fruit, OSU Extension
- Prune highbush blueberries every winter for bigger, better harvests, OSU Extension
- Peach: Leaf curl, WSU Extension HortSense
- Bacterial canker and blast, OSU Extension (Solve Pest Problems)
- Eastern Oregon seed-starting schedule, OSU Extension
- Ponding, plugging and pugging: How to care for wet spring soils, OSU Extension