How to grow a Judas tree
Updated: October 2026
You already have a sapling, a sowing tray, or a packet that might be Cercis siliquastrum and might not. This how to grow a Judas tree guide covers UK site choice, planting depth, water, light pruning, and the two diseases Gardeners' World names often enough to respect. It does not rank the amazon.co.uk listings. The [Judas tree comparison](/hub/trees-and-palms/judas-tree) does that. Products Compared used RHS, Gardeners' World and Hayloft pages checked 19 October 2026. There was no lab trial. Affiliate links may earn a commission at no extra cost to you.
You already have a sapling, a sowing tray, or a packet that might be Cercis siliquastrum and might not.
You already have a sapling, a sowing tray, or a packet that might be Cercis siliquastrum and might not. This how to grow a Judas tree guide covers UK site choice, planting depth, water, light pruning, and the two diseases Gardeners' World names often enough to respect. It does not rank the amazon.co.uk listings. The Judas tree comparison does that. Products Compared used RHS, Gardeners' World and Hayloft pages checked 19 October 2026. There was no lab trial. Affiliate links may earn a commission at no extra cost to you.
Our top picks
| Badge | Product | Form | Species | Watering | Note | Price | Offer |
|---|---|---|---|---|---|---|---|
| Best overall |  SAFLAX SAFLAX Judas tree seeds (60) | 60 seeds | Cercis siliquastrum | Moderate | 4.9 | about £4.55 | View offer |
 Akplants Judas tree sapling (Cercis siliquastrum) | Sapling, 12 in | Cercis siliquastrum | Moderate | 7.1 | about £12.50 | View offer | |
| Best value |  Ipsa Ipsa Chinese redbud seeds (10) | 10 seeds | Cercis chinensis | Moderate | 5.7 | about £2.96 | View offer |
On this page
Where it will actually flower
Cercis siliquastrum is a Mediterranean-region tree for mild, sunny, well-drained UK gardens. The RHS lists H5, full sun or partial shade, and chalk, clay, loam or sand if drainage is good. Gardeners' World says it does best in milder parts of the UK and should not be moved once planted. Horticulture Magazine adds that it flowers more reliably in southern Britain. That is a site warning, not a ban farther north if you accept slower flowering and young-plant frost care. Species and form come first on the Judas tree buying guide.
Pick shelter from cold winds and frost pockets. Waterlogged soil is the common failure. Drought tolerance on the RHS page is for established trees, not a soggy rootball. Hayloft stresses shallow, wide roots and a final spot rather than moving the tree later. If the garden stays wet all winter, fix drainage before you dig.
H5 means about -15°C to -10°C for an established plant in the ground. A first-year seedling in a pot on an exposed balcony is outside that promise. Fleece for new plants matches Hayloft. Container limits are on Judas tree in a pot.
How to plant the sapling
Plant in spring or autumn. In colder districts Hayloft suggests spring so a hard freeze does not hit the roots straight after planting. Dig a square hole as deep as the rootball and about twice as wide. Set the tree at the same depth it was in the pot. Never bury the stem to stabilise a wobbly sapling. The Akplants listing, the top pick if you want a plant rather than seed, is twelve inches tall. That is the young plant, not a cue to plant it in a tiny hole.
Backfill with the excavated soil, water in, and mulch without heaping material against the trunk. Water through the first growing season, then ease off. Outdoor on the listing means outdoor. One UK review of the comparison sapling reported death after indoor care on dampish compost. Starting seed under cover is fine. Keeping the tree indoors for life is not. Once it is in, leave it there. Gardeners' World is explicit: Cercis dislikes disturbance.
Seed, briefly
Seed is a long project. Soak hard seed, sow in well-drained compost, and expect a cold, moist period before warmth. A UK seller outside this Amazon set describes roughly ten weeks cold, then 18–21°C, with germination in one to three months and erratic emergence. SAFLAX reviews in our files often say nothing came up. Treat that as a risk flag. Check for mould and whether you can read the instruction sheet.
First-year seedlings may only reach five to fifteen centimetres. Flowering from seed is often quoted around fifteen years. Akplants claims a sapling may flower in four to seven years, still not next spring. A year-round flowering attribute on Ipsa listings is a form field, not blooms every month. If the packet said Canadian Judas tree, read Judas tree vs eastern redbud before you sow. If you sow indoors, harden off before planting out.
Pruning and the two diseases
Flowers sit on wood at least a year old. The RHS puts Cercis siliquastrum in pruning group 1: little pruning needed. If you must trim, do it after flowering, not in winter before the buds show, or you cut off next year's display. Light shaping in June matches Horticulture Magazine.
Gardeners' World names Verticillium wilt and coral spot. Verticillium wilt has no chemical cure in their account. Cut out affected wood, and if dieback returns you may need to destroy the plant because the fungus persists in the soil. Call an arborist if a mature tree fails fast. Coral spot shows as pinkish pustules on dead wood. Remove infected material and keep the tree unstressed.
Oxford Plants 400 notes that in Britain leaves often appear before flowers. Do not panic in April if leaves arrive first. It is normal here. Call a professional for machinery planting, chronic wet soil, suspected Verticillium wilt when removal is the only safe option, or GOV.UK plant-passport rules if you import plants for planting as a business.
Common questions
When should I plant in the UK?
Spring or autumn. Colder areas often favour spring planting so roots are not immediately frozen.
What soil and sun does it need?
Well-drained soil in full sun or partial shade. Wet winter ground is more dangerous than a dry week in summer once the tree is established.
How deep do I plant?
No deeper than the rootball. Shallow, wide roots mean wide holes, not deep graves.
How often do I water?
Regularly through the first year after planting. Established trees tolerate reasonable drought on the RHS page, but not constant saturation.
When do I prune?
After flowering if needed. Avoid heavy winter cuts that remove flower buds on old wood.
Why has it not flowered?
Young age, shade, frost damage, pruning at the wrong time, or a seed-grown plant still in its first decade. Seedlings can take many years.
What if leaves yellow and a branch dies back?
Suspect Verticillium wilt or coral spot. Inspect the wood, improve drainage, and seek advice before the fungus spreads in the soil.
Can I start the seed indoors and leave the tree there?
Start seed indoors if you wish. Grow the tree outdoors for life. Indoor death matches the cautionary review on the comparison sapling, not a growing method.
Related pages
Sources
Public UK sources used for this comparison. Listing prices, stars and review counts are the amazon.co.uk figures saved for this set on 19 October 2026.
- RHS: Cercis siliquastrum (retrieved 19 October 2026)
- RHS: Cercis canadensis (retrieved 19 October 2026)
- RHS: Cercis chinensis (retrieved 19 October 2026)
- BBC Gardeners' World: how to grow a Judas tree (retrieved 19 October 2026)
- BBC Gardeners' World: Cercis siliquastrum (retrieved 19 October 2026)
- Hayloft: how to grow Cercis (retrieved 19 October 2026)
- GOV.UK: issuing plant passports in Great Britain (retrieved 19 October 2026)
- Oxford Plants 400: Cercis (retrieved 19 October 2026)