When To Plant Rhubarb In Oregon

If you’re a gardener in Oregon, you might be wondering when to plant rhubarb in Oregon. Getting the timing right is the first step to growing a healthy, productive patch that can last for a decade or more. Our cool climate is actually perfect for this perennial vegetable, but you need to work with our unique seasons.

Rhubarb thrives with a good winter chill. Planting at the right moment gives the crown time to establish strong roots before the heat of summer or the dormancy of winter. Let’s look at the best schedule for success across the state.

The absolute best time to plant rhubarb in Oregon is in early spring. This is typically from late March through April, as soon as the ground is workable. The soil is moist from winter rains and starting to warm up, which encourages root growth without stressing the plant.

You can also plant in the fall, around late September to mid-October. This allows the plant to settle in during the cool, wet autumn. Fall planting works well west of the Cascades where winters are milder. In colder, higher-elevation areas, spring planting is safer to avoid frost heave damaging young crowns.

Understanding Your Oregon Growing Zone

Oregon’s climate varies dramatically. Your specific location will fine-tune your planting date.

Western Valleys (Zones 8a-8b): This includes the Willamette Valley and Portland area. Early spring (March-April) is ideal. Fall planting (October) is also very successful here due to mild winters.
Coastal Regions (Zones 8b-9a): With even milder winters, you can plant in early spring or fall. Watch for soggy soil in winter and ensure good drainage.
Southern Oregon (Zones 7b-8a): Areas like Medford have hotter summers. Plant as early in spring as possible so roots establish before the heat. Fall planting can also work well.
Central and Eastern Oregon (Zones 6a-7b): With colder winters and later springs, wait until April or even early May. Focus on spring planting only, and choose a site with full sun.

Choosing the Right Rhubarb Variety

Selecting a variety suited to cooler climates will boost your success. Some classic and reliable choices for Oregon include:

Victoria: A very common, reliable green and red stalk variety. It’s vigorous and productive, though can be less sweet.
Canada Red: Known for its bright red, sweeter stalks. It’s a bit slower to establish but worth the wait.
Crimson Red: Another sweet, red-stalked type that holds its color well when cooked.
German Wine: A heirloom variety with green stalks streaked with pink. It’s extremely cold-hardy and tart.

Step-by-Step Planting Guide

Once you have your crown or division and your timing is right, follow these steps.

1. Site Selection and Soil Prep

Rhubarb needs full sun (at least 6 hours) to partial shade. Pick a spot with well-draining soil, as it hates “wet feet.” This is crucial in rainy western Oregon.

Prepare the soil deeply, as rhubarb will live there for years. Dig a hole about 2 feet deep and wide. Mix in generous amounts of compost or well-rotted manure. This improves drainage and provides nutrients. Aim for a slightly acidic to neutral soil pH (6.0-7.0).

2. Planting the Crown Correctly

Place the rhubarb crown in the prepared hole. The growth buds (or “eyes”) should be facing upward, just 1-2 inches below the soil surface.
If you plant it to deep, the crown may rot. If it’s to shallow, it can dry out or heave from frost.
Backfill the hole with your soil-compost mix and gently firm it around the crown.
Water the plant thoroughly after planting to settle the soil.

3. Spacing and Initial Care

Space rhubarb plants about 3 to 4 feet apart. They get very large! Water new plants regularly during the first growing season, especially during dry spells.

Apply a thick layer of mulch (like straw or shredded bark) around the plant. This conserves moisture, suppresses weeds, and keeps the roots cool. Keep the mulch a few inches away from the base of the crown.

Caring for Your Oregon Rhubarb Patch

Proper care ensures a bountiful harvest for years. The first year is all about establishment.

Year 1: Do not harvest any stalks. Let the plant put all its energy into building a strong root system. Remove any flower stalks that appear immediately.

Year 2: You can harvest lightly for 2-4 weeks in spring. Pull only a few of the largest, outer stalks.

Year 3 and Beyond: You can harvest for 8-10 weeks, stopping by mid-June to early July. Always leave at least one-third of the stalks on the plant so it can continue to photosynthesize and store energy.

Seasonal Maintenance Tasks

Spring: Apply a top dressing of compost or balanced fertilizer as growth begins. Remove any winter mulch from the crown.
Summer: After harvest ends, the plant will grow large leaves. Keep it watered during extended dry periods.
Fall: After the first frost, the foliage will die back. Cut the dead leaves off and add them to your compost pile (avoid leaves with disease). Add a fresh layer of mulch over the crown for winter protection, especially east of the Cascades.

Common Problems in Oregon’s Climate

Our cool, wet springs can encourage some issues. Crown and root rot are the biggest threats, always caused by poor drainage. Ensure your planting site doesn’t stay soggy.

Slugs and snails love young rhubarb leaves in western Oregon. Use organic slug baits, traps, or hand-pick them at night. Good air circulation helps prevent fungal leaf spots. Divide overcrowded clumps every 5-8 years in early spring to maintain plant vigor.

FAQ: Planting Rhubarb in Oregon

Can I grow rhubarb from seed in Oregon?
You can, but it’s not recommended. Rhubarb grown from seed is variable and takes much longer to produce. Starting with a crown from a nursery or a division from a friend’s plant gives you a predictable variety and a head start.

Is it too late to plant rhubarb in May?
In most of Oregon, planting in May is still fine, especially if you keep it well-watered going into summer. For the hottest parts of Southern Oregon, it might be better to wait until fall.

Why does my rhubarb keep flowering?
Flowering (bolting) is often triggered by stress, like drought, poor soil, or an old, crowded plant. It can also just be genetic. Simply cut the flower stalk off as soon as you see it to direct energy back to the roots and stalks.

Can I plant rhubarb in a container?
Yes, but choose a very large pot (at least 20 gallons). Use high-quality potting mix and water frequently, as containers dry out fast. It may not be as long-lived as in-ground plants, and will need more feeding.

When is the best time to divide rhubarb?
Early spring, just as the first pink buds are swelling on the crown, is the ideal time to divide. This gives the new divisions a full season to recover. You can also divide in early fall if you have too.

By following these guidelines tailored to Oregon’s cool climate, you’ll be on your way to a successful rhubarb patch. With proper timing and care, you’ll enjoy homegrown stalks for pies, sauces, and more for many springs to come.