Harvesting rhubarb: how & when to pick rhubarb

Regina
Regina
Regina
Regina

I studied horticultural sciences at university and in my free time you can find me in my own patch of land, growing anything with roots. I am particularly passionate about self-sufficiency and seasonal food.

Favourite fruit: quince, cornelian cherry and blueberries
Favourite vegetables: peas, tomatoes and garlic

Ready to pick from spring onwards, rhubarb is one of the first crops of the year. Discover how to harvest rhubarb and when to stop picking it.

Prepared rhubarb on a table
Depending on the variety, you can start picking rhubarb from March onwards [Photo: Nadezhda Nesterova/ Shutterstock.com]

Along with being commercially produced, rhubarb (Rheum x hybridum) is commonly grown in allotments and home gardens. Grown for its tasty stems, you can use rhubarb in crumbles, jams, pies and even for making rhubarb wine. Read on to find out how and when to pick rhubarb as well as when to stop picking rhubarb.

When to pick rhubarb?

As a perennial, rhubarb dies back in the winter before regrowing again in spring. If you are wondering when to pick rhubarb, the answer is generally around April. However, the harvesting period depends on the rhubarb variety, as early varieties can start cropping from March and main crop varieties from around May. However, you can tell when rhubarb is ready to pick when the stems are thick and around a minimum of 25 to 35cm long.

Rhubarb plants need time to establish before being harvested from. After planting rhubarb, you should not remove any of the stems during the first year and only harvest sparingly in the second year.

Tip: for an earlier and sweeter crop of stems, try forcing rhubarb under a pot.

Rhubarb plant with ripe stems
To help ensure that your rhubarb plant crops well the following year, cease harvesting in mid-summer [Photo: Peter_Fleming/ Shutterstock.com]

When to stop picking rhubarb?

In general, the rhubarb harvest time lasts around 10 to 12 weeks from the time you start picking it. In practice, this generally means that you can keep harvesting rhubarb until late June or early July. When to stop picking rhubarb is important, as after being harvested for several weeks, the plants need time to recuperate in order to crop well again the following year. In a mild summer, rhubarb can keep producing stems up until September, so willpower is required to leave it alone.

How to harvest rhubarb?

To harvest rhubarb stems, simply grasp the stem low down with one hand and pull gently away from the centre of the plant. You can also cut away the stem with a knife. However, cutting rhubarb can lead to the wounded stub rotting and open the plant up to potential diseases. Having harvested your rhubarb, prepare the stems by removing the leaves, as they are toxic due to their high oxalic levels and must not be eaten. Instead, you can add them to the compost and let them decompose.

When harvesting rhubarb, you can pick the stems as and when you need them. It is best to remove only a few stems at a time to avoid reducing the number of leaves significantly and the plant’s ability to photosynthesise.

With the right care, rhubarb plants can remain productive for up to a decade and sometimes even longer. However, to prevent plants from becoming congested, you can divide them every 5 years to propagate new rhubarb plants.

The levels of oxalic acid in rhubarb rise over the growing season and the stems, just like earlier in the summer, should only be eaten in moderation. This is due to the fact that excessive consumption of oxalic acid can lead to hyperoxaluria and kidney stone formation. The highest levels of oxalic acid are found in raw rhubarb stems. On the other hand, peeling and cooking decrease the levels. Due to the levels of oxalic acid in rhubarb, consumption is generally not recommended for those who are pregnant or breastfeeding, toddlers, or people with kidney or liver issues.

The ends of rhubarb stems
Picking rhubarb by pulling the stems ensures that no stubs are left to potentially rot [Photo: Lia Kos/ Shutterstock.com]

When placed in the fridge, you can keep rhubarb fresh for around 10 to 14 days. If you want to preserve the stems for longer, you can discover more in our article on how to store rhubarb.