Harvesting Rhubarb in September: What You Need to Know

With its tart and tangy flavor, rhubarb is a unique early spring treat. But did you know you can often continue harvesting rhubarb into September and even later in some gardening zones? Knowing when and how to harvest rhubarb in the fall ensures you make the most of this cold-tolerant perennial.

In this in-depth guide, we’ll cover:

• How the rhubarb harvest season extends into fall
• When September rhubarb harvesting can occur
• Signs your rhubarb is still usable that late
• How to harvest rhubarb in September
• Whether fall growth can be harvested
• Storing and preserving the late season crop
• Special care of rhubarb in fall
• Revitalizing overharvested plants
• Maximizing next year’s yield

Let’s explore the nuances of harvesting rhubarb into the fall and how to stretch out its productive season.

Understanding the Extended Rhubarb Harvest Season

While most gardeners associate rhubarb with spring, mature plants can continue producing harvestable stalks under the right conditions well into September and sometimes October or November

Here’s how rhubarb’s cultivation season typically spans spring, summer and fall:

• Spring – The primary harvest season runs April through June, Stalks are most tender and flavors milder

• Summer – Heat causes rhubarb to go dormant and stalks to become stringy. Plants are not harvested June through August.

• Fall – Cooler weather awakens dormant plants. Usable stalks often reemerge September into fall.

So while rhubarb is at peak harvest in spring, you shouldn’t disregard your rhubarb patch come September!

Determining If September Rhubarb is Harvestable

It takes an experienced eye to determine if a rhubarb plant has viable stalks in September. Here are telling signs stalks are still harvestable:

• Healthy green leaves present
• Firm, upright stalks
• Stalks snap cleanly rather than bend
• No hollowness or dryness inside stalks
• No noted signs of disease or rot

Conversely, September stalks to avoid show signs like:

• Leaves yellowed or wilted
• Stalks limp, bending or horizontally oriented
• Exterior blemishes, scarring or mushiness
• Stalks pull apart rather than snapping off
• Pith is dry versus moist and firm

Getting familiar with what desirable versus over-the-hill stalks look like will steer you right at fall harvest time.

How to Harvest Rhubarb in September

When September rhubarb proves harvestable, employ these best practices:

• Gently twist and pull only largest, healthiest stalks from outer portions of the plant.

• Use a sharp knife to cut each stalk at its base rather than breaking it off.

• Take no more than 1/3 of stalks from each plant. Never harvest all at once.

• Stagger your fall harvest over 2-3 weeks. Stop if plant seems stressed.

• Allow smaller, weaker stalks to remain on the plant to feed and strengthen it.

• Always discard leaves, which are poisonous. Only eat stalks.

With care, you can gather enough good stalks for a seasonal treat without harming the plant.

Should You Harvest Fall Foliage Growth?

Some gardeners wonder if they should also harvest the smaller tender foliage growth that emerges from the rhubarb crown in fall. It’s best to avoid harvesting fall foliage for these reasons:

• Fall growth is essential to replenishing the plant’s energy stores after spring/summer dormancy.

• Removing fall growth can weaken the plant going into winter.

• Fall foliage stalks are more stringy and less flavorsome.

Allow all late season rhubarb growth to remain untouched to ensure next year’s vigorous harvest.

Storing and Preserving the September Rhubarb Crop

Late season rhubarb often arrives in a glut. Follow these tips for storing your September harvest:

• Store freshly cut stalks in perforated plastic bags in the refrigerator for 1-2 weeks.

• Freeze trimmed stalks for longer term storage. Blanch first for highest quality.

• Cook stalks with added sugar into jams, compotes, sauces and baked goods. Refrigerate or can preserves.

• Dehydrate sliced stalks in a food dehydrator. Store dried rhubarb in airtight containers.

• Pickle tender young stalks for a tart condiment to enjoy all year.

With proper storage methods, you can keep enjoying your fall rhubarb through the winter.

Special Care of Rhubarb Plants in Fall

Rhubarb needs some TLC as it winds down for the year. Follow these fall plant care tips:

• Stop harvesting once frosts commence, usually by October or November.

• Allow all remaining stalks and leaves to wither naturally over winter. Don’t remove.

• Mulch around the crown before ground freezes for insulation if you’re in a frigid climate.

• Trim off any broken stalks or insect-damaged leaves in late fall cleanup.

• Fertilize in early fall by topdressing with aged manure or compost. This feeds the next season’s growth.

• Division or transplanting if needed should be done in early fall as well.

Attend to these care needs to ensure your rhubarb thrives year after year.

Revitalizing Overharvested Rhubarb Plants

Sometimes a rhubarb plant suffers if too much was harvested in spring and fall combined. Here’s how to nurse it back to health:

• Avoid harvesting any stalks next season. Allow full foliage growth.

• Fertilize generously with nitrogen-rich manure or compost early and again mid-season.

• Water regularly if rainfall is insufficient. Reduce other stresses.

• Protect the plant from pests like crown borers which can further weaken it.

• Propagate the variety by division to hedge your bets.

• Monitor and limit harvests in future years to avoid overtaxing this perennial again.

With TLC and reduced harvesting, an over-picked rhubarb plant can make a comeback!

Maximizing Rhubarb Yields Next Year

Here are some added tips for keeping rhubarb healthy and productive from one year to the next:

• Every 3-5 years, dig up and divide congested plants in early spring. Replant vigorous divisions.

• Topdress annually each spring with rich compost or well-rotted manure.

• Eliminate all weeds, which compete for nutrients. Keep the area around plants clean cultivated.

• Ensure rhubarb receives consistent moisture, especially during peak growth periods.

• Protect developing stalks from insect damage and rotting.

Follow these best practices to enjoy bigger and better harvests.

Enjoying September’s Rhubarb Treats

While most gardeners relegate rhubarb to spring, those in the know can savor this tart, hardy perennial well into fall. A little knowledge of its late season habits can extend your enjoyment of rhubarb’s versatility. Squeeze a few more pies, jams, or sweet & tangy treats out of your patch this September and beyond!