When To Stop Picking Rhubarb Uk

Knowing when to stop picking rhubarb UK is the key to a healthy, productive plant that comes back stronger every year. Getting this timing right ensures you enjoy a great harvest without weakening your crown.

Rhubarb is a hardy perennial, and its harvest season isn’t open-ended. Picking for too long drains the plant’s energy reserves, which it needs to survive the winter and push up strong new stalks next spring. This guide will walk you through the clear signs that tell you it’s time to put down your knife and let your rhubarb rest.

The traditional and most reliable rule is to finish harvesting by the end of June, or around Midsummer’s Day on the 24th. This isn’t just an old wives’ tale; it’s based on the plant’s natural cycle. After this point, rhubarb growth slows and the stalks often become thinner, tougher, and more acidic.

Why the Mid-Summer Cut-Off is So Important

Stopping your harvest allows the plant to do essential work. From mid-summer onward, it focuses on rebuilding its root system and storing carbohydrates for the next season. If you keep picking, you’re literally stealing its food supply for the future.

This can lead to a weak plant next spring, with spindly stalks and low yields. In severe cases, continous picking can even kill the crown. Letting it grow freely after June ensures it has enough leaf surface area to photosynthesize and build up those all-important energy stores.

Key Signs Your Rhubarb is Telling You to Stop

Even if the calendar says late June, your plant will give you visual clues. Watch for these signals:

Thinner, Wispy Stalks: New stalks emerging are no longer thick and succulent.
Increased Leaf Size: The leaves become disproportionately large compared to the stalk.
Tougher Texture: Stalks lose their crispness and become stringy or fibrous.
Flower Stalk Development: The plant sends up a tall, central flower stalk. This is a major drain on energy.

What to Do About Rhubarb Flowers

If a flower stalk (or seed head) appears, cut it off as soon as you spot it at the base. Use a sharp knife and make a clean cut. This redirects the plant’s energy back into the roots and edible stalks, rather than into producing seeds.

The Role of Weather and Plant Age

A cold, late spring might delay growth, meaning you could pick a little into early July if the stalks are still robust. Conversely, a very hot, dry early summer might bring the season to an earlier end. Always let the plant’s condition be your final guide.

Also consider the age of your plant. Never harvest from a newly planted crown in its first year. In its second year, only take a few stalks over a 4-week period. Established plants (3+ years old) can be harvested fully from April until the stop date.

How to Harvest Correctly (And How Not To)

How you pick also affects the plant’s health. Follow these steps for sustainable harvesting:

Choose stalks that are at least 25-30cm (10-12 inches) long and are firm and thick.
Hold the stalk firmly at the base and twist it gently to the side, pulling it away from the crown. It should release cleanly. You can also use a sharp knife to cut the stalk at the base, but twisting is often prefered as it causes less damage to the crown.
Immediately trim off the large, poisonous leaf and add it to your compost heap.
Never take more than one-third to half of the total stalks from a plant at any one time.

Avoid the temptation to simply cut stalks off at ground level, as the leftover stump can rot and invite disease into the crown. Always remove the whole stalk from the base.

What to Do After You Stop Picking

Your job isn’t over when harvesting ends. Post-harvest care is crucial for next year’s crop.

Let It Grow: Allow all the remaining leaves and stalks to grow unchecked. This is the plant’s recovery phase.
Feed the Plant: In early July, after your last pick, give the plant a boost with a balanced fertiliser or a generous mulch of well-rotted manure or compost around (not over) the crown. This replaces nutrients used during the growing season.
Water in Dry Spells: Continue to water during prolonged dry periods in summer to support this growth.
Autumn Clean-Up: After the first frost, when the leaves have died back completely, you can remove the old foliage. The frost helps break down any residual oxalic acid in the leaves.

Forcing Rhubarb and Harvest Timing

If you force rhubarb (cover it in winter for an early, tender crop), the rules change slightly. Forced crowns need extra care because the early harvest is very draining.

Harvest forced rhubarb as soon as the stalks are ready, usually from late winter.
Once you stop harvesting forced rhubarb, remove the forcing pot or cover.
Do not force the same crown two years in a row. It must be allowed to grow normally for at least one full season to recover its strength. Mark it so you remember not to pick from it the following winter.

Common Questions About Rhubarb Harvests

Can I pick rhubarb in August or September in the UK?

It is not recommended. While you might get a few late stalks, the high levels of oxalic acid that build up as the season progresses can make them unpleasant and potentially more irritating if consumed in very large quantities. It’s much better for the plant’s long-term health to stop by July.

Is it true rhubarb becomes poisonous later in the year?

The leaves are always poisonous due to oxalic acid and other compounds. The stalk’s oxalic acid content does increase later in summer, but the primary reason to stop picking is plant vigor, not acute toxicity. The stalks often become too sour and tough to enjoy anyway.

My rhubarb has very thin stalks, what did I do wrong?

Thin stalks are a classic sign of over-harvesting or harvesting for too many seasons without a break. It can also mean the plant is overcrowded and needs dividing, or it’s lacking nutrients. Ensure you follow the seasonal stop date and feed the plant well in spring and after harvesting.

When is the best time to divide and replant rhubarb?

The ideal time is during dormancy, in late autumn or early winter. Lift the whole crown with a fork and use a spade to split it into sections, each with at least one healthy bud. Replant these divisions with the bud just below the soil surface.

A Simple Seasonal Checklist

February-March: Apply a general fertiliser around established crowns.
April-June: Harvest stalks by twisting from the base. Never strip the plant completely.
End of June: Stop picking. Apply a mulch of compost or manure.
July-September: Let plant grow freely. Water during drought.
October-November: After frost, clear away old dead leaves.
Every 5-6 years: Divide overcrowded crowns in late autumn.

Sticking to the simple calender of stopping your rhubarb harvest by late June ensures you’ll have a reliable, year-after-year supply from your garden. By listening to your plant and giving it the recovery period it needs, you’re investing in countless future crumbles and pies. Remember, a little restraint in summer leads to a much more generous spring harvest.