Should I Soak Bare Root Perennials Before Planting? UK Gardening Guide

When you buy bare root perennials in late autumn or early spring, they look like a bundle of dry sticks with roots wrapped in sawdust or moss. It’s easy to wonder: should I soak bare root perennials before planting? The answer isn’t just yes or no-it’s about timing, temperature, and what your plant actually needs to survive its first weeks in the ground.

Why bare root perennials are sold dry

Bare root perennials are dug up in winter when the plant is dormant. No soil, no pots, no extra weight. This cuts shipping costs and reduces transplant shock. Companies like Crocus, Thompson & Morgan, and RHS-recommended nurseries ship them this way because it works-when done right. But dry roots don’t mean dead roots. They’re just resting. Your job is to wake them up gently.

Think of it like a hibernating bear. You don’t throw it into a warm pool. You ease it into warmth. Same with roots.

What happens if you skip soaking

I’ve seen gardeners in Brighton plant bare root hostas straight from the box. They dug the hole, dropped the roots in, and watered lightly. Two weeks later? Half the plants were dead. The roots had dried out during transport and couldn’t rehydrate fast enough to reach the soil moisture.

Roots are living tissue. If they’re shriveled and brittle, they’re stressed. Without enough water, they can’t absorb nutrients or send out new feeder roots. The plant might survive, but it won’t thrive. It’ll lag behind others planted at the same time. And in the UK’s unpredictable spring weather-cold snaps, wet spells, sudden sun-you can’t afford a weak start.

How long to soak bare root perennials

Soak them for 1 to 2 hours in a bucket of lukewarm water. Not hot. Not icy. Room temperature works best. Rainwater is ideal if you’ve got a water butt. Tap water is fine too-just let it sit for 30 minutes to let chlorine evaporate.

Don’t leave them overnight. Soaking too long can drown the roots. Roots need oxygen, not a bath. After 2 hours, they’ll look plump and flexible. That’s your signal they’re ready.

What to do while soaking

While your perennials are soaking, prep the planting spot. Dig a hole twice as wide as the root spread. Loosen the soil at the bottom. Mix in a handful of compost or well-rotted manure. Don’t add fertilizer yet-new roots are sensitive. Too much can burn them.

Some gardeners add rooting hormone to the water. It helps, but it’s not essential. If you’re planting a few plants, skip it. If you’re planting a whole border of expensive bare root peonies or iris, then yes-use it. But make sure it’s a powder, not a gel. Gel can trap moisture and rot the crown.

How to plant after soaking

Lift the plant out of the water. Gently shake off excess. Don’t scrub the roots. Don’t trim them unless they’re broken or rotting. Healthy roots are white or light tan. Black, mushy roots? Cut them off with clean secateurs.

Place the plant in the hole. Spread the roots out like fingers. Make sure the crown-the point where roots meet stems-is level with the soil surface. Plant too deep? You’ll smother the crown. Too high? The roots dry out.

Backfill with soil. Firm it gently with your hands. Water thoroughly. Not a light sprinkle. A full bucket. This settles the soil around the roots and eliminates air pockets. Then mulch with straw or leaf mould to keep moisture in and weeds out.

When to plant bare root perennials in the UK

The best time to plant bare root perennials in the UK is between late October and mid-April. That’s when the plants are dormant and the ground isn’t frozen. Avoid planting in December if the soil is waterlogged or icy. January and February are often the best months-cool, moist, and quiet.

Spring planting (March-April) is also good, but you’re racing the clock. Once the plant starts waking up, it needs water fast. If you wait until the buds are swelling, you’re already behind. Late October to November is ideal for perennials like peonies, daylilies, and ornamental grasses. They’ll settle in before winter and burst into growth by May.

Common mistakes to avoid

• Soaking for more than 2 hours-roots suffocate
• Planting in frozen ground-roots can’t grow
• Adding fertiliser at planting-burns tender roots
• Planting too deep or too shallow-kills the crown
• Forgetting to water after planting-drying out kills more than dry roots

I once planted a bare root astilbe in early March. I soaked it for 30 minutes, planted it, and thought I was done. Two weeks later, it looked like it had given up. I dug it up. The roots were dry as paper. I’d forgotten the soil was still cold and slow to absorb water. I replanted it, soaked it properly, and gave it a deep drink. It flowered in June. Same plant. Different care.

What to expect after planting

Don’t expect fireworks. Bare root perennials take time. In the first month, you might see nothing. No leaves. No growth. That’s normal. The plant is building roots underground. By late spring, you’ll see shoots. By summer, it’ll be taller and bushier than a potted plant from the garden centre.

Some perennials, like oriental poppies or lupins, take two years to really settle. Be patient. The reward is worth it: stronger plants, better blooms, and lower cost.

When not to soak

If the roots are already moist and plump when you open the package, skip the soak. Some nurseries ship in damp sphagnum moss. That’s enough. Soaking again could cause rot.

Also, if the ground is frozen solid or the forecast says a hard frost is coming in 24 hours, delay planting. Soak the roots, then keep the plant in a cool, dark place (like a garage or shed) until the soil thaws. Don’t leave them outside.

Pro tip: Label everything

Bare root perennials often look identical before they grow. A peony root and a phlox root? Both are brown and tangled. Label them with a paint pen on a stone or a plastic tag. Write the name and date. Otherwise, you’ll forget which is which. I’ve dug up three plants thinking they were all the same-and lost two because I didn’t know what I was dealing with.

Final answer: Yes, soak them-but correctly

Soaking bare root perennials before planting isn’t optional if you want them to survive and thrive. It’s a simple step that makes a huge difference. One to two hours in lukewarm water. No longer. No hotter. Then plant immediately into prepared soil. Water deeply. Mulch. Wait. And trust the process.

It’s not magic. It’s just biology. Roots need water to wake up. Give them that, and they’ll reward you for years.