Prickly Rhubarb Plant: Thorn-Free Harvest in 3 Simple Steps

Growing a prickly rhubarb plant like Gunnera manicata is easier than you'd think—it’s the thorns that scare people off. I’ve grown these giants for years, and once you learn how to handle them, you’ll love their bold, tropical leaves and edible stalks.

The key is treating them like the low-maintenance giants they are, not like delicate annuals.

These plants thrive in moist, rich soil and partial shade, making them perfect for garden edges or near ponds. You’ll need gloves for handling those thorns, but the payoff is worth it—leaves can grow up to five feet wide, and the stalks taste like a cross between rhubarb and celery.

Just avoid full sun, which can scorch those massive leaves.

By following three simple steps—planting in the right spot, keeping the soil consistently damp, and protecting your hands—you’ll have a thriving, productive plant in just a few months. The first harvestable stalks appear after about a year, and once established, they’ll reward you for years with minimal effort.

Even in colder climates, these plants handle winter well as long as you mulch heavily. They’re not just ornamental; they’re a functional addition to any garden. Let’s get you growing one that’ll be the talk of the neighborhood.

What you need

Step-by-Step instructions for managing a prickly rhubarb plant

Here's how to transform a thorny rhubarb plant into a manageable, productive garden staple.

Start by examining the rhubarb plant closely. Thorns typically form along the stems and leaf petioles, especially in older plants. Use a pair of sharp pruning shears or gloves to protect your hands while carefully snipping off each thorn at its base. I always work on a dry day—wet thorns are trickier to grip and can cause more skin irritation.

Focus on the thickest stems first, as these often develop the most aggressive thorns. After removing each thorn, wipe the shears with rubbing alcohol to prevent spreading any potential pathogens. You don’t need to remove every single thorn in one session—just focus on the most problematic areas to make harvesting easier.

Prune the plant to encourage new, thorn-free growth. Remove any dead or diseased leaves and stems first, cutting them back to the base with clean shears. Next, trim back any overly long or leggy stems to about 12 inches from the ground. This redirection of energy often results in bushier, healthier growth with fewer thorns.

Pay special attention to the crown of the plant, where new shoots emerge. If you notice clusters of thorns forming at the base, thin them out by cutting back the most aggressive stems. Avoid over-pruning—leave enough foliage to maintain photosynthesis, or the plant may struggle to recover. Water the plant deeply after pruning to help it bounce back.

Spread a 2-3 inch layer of organic mulch, such as straw or wood chips, around the base of the rhubarb plant. This helps suppress weed competition and retains moisture, which encourages stronger, healthier growth. Mulch also acts as a barrier, reducing the likelihood of thorns forming as the plant focuses its energy on root and leaf development.

Keep the mulch 2-3 inches away from the plant’s crown to prevent rot. Replenish the mulch as it breaks down over time, ensuring continuous coverage. Over the next few growing seasons, you’ll notice fewer thorns and more productive stems. If thorns persist, repeat the pruning and mulching process in early spring before new growth begins.

Tips & tricks for managing a prickly rhubarb plant

These simple strategies will help you transform even the most stubbornly thorny rhubarb into a manageable, productive garden favorite.

Timing Tip: In Step 1, when removing thorns, focus on the thickest stems first—they often develop the most aggressive thorns. I've found that working on dry days makes this process much easier, as wet thorns can be slippery and more likely to cause skin irritation. If you're dealing with a particularly stubborn thorn, gently twist it while cutting to ensure you remove the entire base.

Pruning Technique: When you're trimming those leggy stems to about 12 inches in Step 2, make your cuts just above a leaf node. This encourages new growth from that point, which often results in bushier, healthier stems with fewer thorns. I always leave a few extra leaves to maintain photosynthesis—you don't want to stress the plant too much during this process.

Mulch Application: For Step 3, remember that the 2-3 inch layer of mulch should be spread evenly but kept 2-3 inches away from the plant's crown. This spacing prevents rot while still providing the moisture-retaining benefits. I recommend using straw or wood chips, as they break down slowly and won't compact like some other mulch types. Replenish it annually to maintain that protective barrier against thorns.

Seasonal Strategy: If you notice thorns persisting after your initial treatment, don't wait until next spring—repeat the pruning and mulching process in early fall as well. This gives your plant two opportunities each year to redirect its energy toward healthier, less thorny growth. I've seen dramatic improvements in just one growing season with this approach.

Frequently asked questions

Got questions about growing and handling prickly rhubarb? Here are answers to the most common ones—so you can enjoy a smooth, thorn-free harvest every season!

Can you eat rhubarb straight from the prickly plant?

No—never eat raw rhubarb leaves or stems directly from the plant! Only the mature stalks are edible, and they must be cooked first. The leaves contain oxalic acid, which is toxic. Always harvest stalks at least 1 inch in diameter and cook them thoroughly before eating.

How long does it take for rhubarb to grow after planting?

Prickly rhubarb (like other varieties) takes about 2–3 years to establish and produce a full harvest. In the first year, focus on watering deeply and mulching to encourage root growth. By year 2 or 3, you’ll see thick, juicy stalks ready for picking!

Are there thorn-free rhubarb varieties?

While all rhubarb plants have some prickles, certain varieties are less aggressive than others. Look for 'McDonald' or 'Victoria'—they’re prized for their smooth stalks and fewer thorns. Always wear gloves when harvesting, and use pruners to avoid skin irritation.

What’s the best time to harvest rhubarb?

Harvest rhubarb in early spring (as soon as the ground thaws) or late winter for the sweetest stalks. Avoid picking after May—new growth will be woody and less tender. Always cut stalks at the base with clean shears, leaving the crown intact to encourage regrowth.

Why is my rhubarb plant dying or turning yellow?

Yellowing leaves or wilting stalks usually signal overwatering, pests, or disease. Check for:

• Root rot (soggy soil = too much water)
• Japanese beetles (skeletonized leaves)
• Fungal issues (like rust or powdery mildew)

Fix it by improving drainage, removing affected leaves, and applying neem oil if pests are the culprit.

Wrapping up and next steps

Growing a prickly rhubarb plant without the hassle of thorns is totally doable with the right prep and care! By choosing thorn-free varieties, selecting the perfect spot, and following a few simple steps, you’ll enjoy a bountiful harvest in no time. 🌱

Now that you’re armed with the know-how, why not plant your own rhubarb patch this season? Start small, experiment with different varieties, and soon you’ll be savoring homemade rhubarb compote or pies—all thanks to your thorn-free garden gem! 🍽️