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PERSICARIA amplexicaulis 'Blackfield'
Commonly known as Knotweed, Polygonum
Slender flowers in deep red-black. A smouldering beauty
Further Reading....
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Semi-evergreenKeeps some of its foliage all year, and will drop some leaves as well.Ovate, lance-shaped, pointed, mid-green leaves to 25cm (10in) long, slightly puckered.
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RedDeep red black
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Height1.2m (4ft)
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Spread1.2m (4ft)
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HerbaceousEarly in the year, typically January till end of March, herbaceous plants might be supplied in 9cm pots to ensure timely despatch.Robust, clump-forming perennial
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Hardy - cold winterHardy in most places throughout the UK even in severe winters. May not withstand open/exposed sites or central/northern locations. Plant can withstand temperatures down to -15°C (5°F)
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Full sun
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Partial shade
PERSICARIA amplexicaulis 'Blackfield'
- Details
- Description
- Mature Size
- Tips and Advice
- Goes Well With
- Planting Combinations
- Other Suggestions
- See Also...
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Additional FeaturesPests & DiseasesNonePlace of originGarden originResistant to honey fungusThese plants have little or few problems with honey fungus.
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Flower ShapeBell/LanternNarrowly bell-shaped 5mm (¼in) longSpikesLong-stalked narrow spikes to 10cm (4in) long
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Garden Location/ConditionsBorderSuitable for a mixed or herbaceous border
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HardinessFully hardy
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Seasonal InterestSummer
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Soil ConditionsTolerates allAny moist soil.
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WildlifeBee friendlyRabbit Resistant
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Herbaceous Plants - Video Collection
- Dividing Herbaceous Perennials - Video Tip ondemand_video
- Spring Planting Osteospermums - Video Tip ondemand_video
- Dividing Summer Perennials - Video Tip ondemand_video
- Dividing summer flowering Hemerocallis - Video Tip ondemand_video
- Summer propagation - Video Tip ondemand_video
- Self-seeding aquilegia - Video Tip ondemand_video
- Supporting Plants - Video Tip ondemand_video
- Dead heading meconopsis - Video Tip ondemand_video
- Dead heading Delphiniums - Video Tip ondemand_video
- Feeding herbaceous peonies - Video Tip ondemand_video
- Overpotting Problems - Video Tip ondemand_video
Persicaria - Growing Guide
1.2m (4ft)
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1.2m (4ft) |
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https://www.burncoose.co.uk/site/UserFiles/Image/ComboPhotos/square/350_5344_Arundo_donax_varversicolor_Persicaria_amplexicaulis_Blackfield,_.jpg)
![](
https://www.burncoose.co.uk/site/UserFiles/Image/ComboPhotos/square/1358_1750_5344_Cotinus_Rubrifolius,_Eryngium_giganteum_Miss_Willmotts_Ghost,_Persicaria_amplexicaulis_Blackfield,_.jpg)
![](
https://www.burncoose.co.uk/site/UserFiles/Image/ComboPhotos/square/6407_3166_euphorbia_pasturei_AND_persicaria_01.jpg)
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https://www.burncoose.co.uk/site/UserFiles/Image/ComboPhotos/square/2159_4043_5344_plant_combi_004~01.jpg)
![](
https://www.burncoose.co.uk/site/UserFiles/Image/ComboPhotos/square/1747_3166_5701_plant_combi_038~01.jpg)
![](
https://www.burncoose.co.uk/site/UserFiles/Image/ComboPhotos/square/3204_5344_phlox_rijnstroom_AND_persicaria_amplexicaulis_blackfield_01.jpg)
![](
https://www.burncoose.co.uk/site/UserFiles/Image/ComboPhotos/square/3744_5344_rose_AND_persicaria_amplexicaulis_blackfield_01.jpg)
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https://www.burncoose.co.uk/site/UserFiles/Image/ComboPhotos/square/4817_5344_6165_plant_combi_014~01.jpg)
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https://www.burncoose.co.uk/site/UserFiles/Image/ComboPhotos/square/3936_4817_5344_5792_6165_plant_combi_015~01.jpg)
![ARUNDO donax var. versicolor ARUNDO donax var. versicolor](https://www.burncoose.co.uk/site/img/products/square/aundodanax_var_versicolor_350.jpg)
ARUNDO donax var. versicolor
Giant reed
Available from £17.50
![COTINUS coggygria 'Rubrifolius' COTINUS coggygria 'Rubrifolius'](https://www.burncoose.co.uk/site/img/products/square/cotinus_coggygria_rubrifolius_1358a.jpg)
COTINUS coggygria 'Rubrifolius'
Purple smoke bush
![ERYNGIUM bourgatii 'Picos Blue' ERYNGIUM bourgatii 'Picos Blue'](https://www.burncoose.co.uk/site/img/products/square/eryngium_bourgatii_picos_blue_1747.jpg)
ERYNGIUM bourgatii 'Picos Blue'
Sea holly
Available from £13.50
![ERYNGIUM giganteum 'Miss Willmott's Ghost' ERYNGIUM giganteum 'Miss Willmott's Ghost'](https://www.burncoose.co.uk/site/img/products/square/eryngium_giganteum_miss_willmotts_ghost_1750a.jpg)
ERYNGIUM giganteum 'Miss Willmott's Ghost'
Giant sea holly
Available from £5.00
![EUPHORBIA x pasteurii EUPHORBIA x pasteurii](https://www.burncoose.co.uk/site/img/products/square/euphorbia_pasturei_6407.jpg)
EUPHORBIA x pasteurii
Available from £17.50
![HEMEROCALLIS HEMEROCALLIS](https://www.burncoose.co.uk/site/img/products/square/hemerocallis_2159.jpg)
HEMEROCALLIS
Daylily
![MONARDA 'Prairie Night' MONARDA 'Prairie Night'](https://www.burncoose.co.uk/site/img/products/square/monarda_prairie_night_5701.jpg)
MONARDA 'Prairie Night'
Available from £13.50
![PERSICARIA PERSICARIA](https://www.burncoose.co.uk/site/img/products/square/persicaria_microsephala_red_dragon_5140~1s.jpg)
PERSICARIA
(Polygonum) - Knotweed
![PERSICARIA alpina PERSICARIA alpina](https://www.burncoose.co.uk/site/img/products/square/persicaria_alpina_6165a.jpg)
PERSICARIA alpina
Available from £12.50
![PHLOX divaricata 'Chattahoochee' PHLOX divaricata 'Chattahoochee'](https://www.burncoose.co.uk/site/img/products/square/phlox_chatahooche_4817a.jpg)
PHLOX divaricata 'Chattahoochee'
Border phlox
Available from £12.50
![PHLOX paniculata 'Rijnstroom' PHLOX paniculata 'Rijnstroom'](https://www.burncoose.co.uk/site/img/products/square/phlox_paniculata_rijnstroom_3204.jpg)
PHLOX paniculata 'Rijnstroom'
Border phlox
Available from £12.50
ROSA POLYANTHA & FLORIBUNDA
Rose
![SALVIA 'Embers Wish' SALVIA 'Embers Wish'](https://www.burncoose.co.uk/site/img/products/square/salvia_embers_wish_5792s.jpg)
SALVIA 'Embers Wish'
Available from £13.50
![SEDUM spectabile 'Brilliant' SEDUM spectabile 'Brilliant'](https://www.burncoose.co.uk/site/img/products/square/sedum_spectabile_brilliant_3936a.jpg)
SEDUM spectabile 'Brilliant'
Ice plant
Available from £13.00
![STACHYS lanata 'Silver Carpet STACHYS lanata 'Silver Carpet](https://www.burncoose.co.uk/site/img/products/square/stachys_lanata_silver_carpet.jpg)
STACHYS lanata 'Silver Carpet
Lambs' ear, Woolly betony
Available from £12.50
Useful extras...
![](https://www.burncoose.co.uk/site/img/products/squaremedium/Vitax_Q4_6202.jpg)
Fertilisers & Feeds - Vitax
Q4 Pelleted Fertiliser
A useful fertiliser suitable for use on a wide variety of plants. Q4 provides all the nutrients and trace elements essential for vigorous growth, abundant flowering and ripening of fruit.
3 options from £6.00
![](https://www.burncoose.co.uk/site/img/products/squaremedium/grow_your_own_front_22.jpg)
Fertilisers & Feeds - Empathy
Afterplant - Grow Your Own
AFTER PLANT GROW YOUR OWN seaweed is ready to use liquid concentrate that was specially formulated be used on all edible plants.
Only £8.00
![](https://www.burncoose.co.uk/site/img/products/squaremedium/tomatoe_front.jpg)
Fertilisers & Feeds - Empathy
Afterplant - Tomatoes
AFTER PLANT TOMATO FEED Liquid Concentrate with Bio stimulant is a high potash liquid concentrate containing seaweed extract, plant derived amino acids and other nutrients specifically formulated to benefit tomatoes and greenhouse plants.
Only £8.00
![](https://www.burncoose.co.uk/site/img/products/squaremedium/rootgrow_6203.jpg)
Fertilisers & Feeds - Empathy
Rootgrow mycorrhizal fungi
Recommended by the RHS. Contains Rootgrow™ mycorrhizal fungi. Suitable for all trees and shrubs (except rhododendrons, azaleas, heathers, cranberries and blueberries)
3 options from £3.00
![](https://www.burncoose.co.uk/site/img/products/squaremedium/RootgrowEricoid_6204.jpg)
Fertilisers & Feeds - Empathy
Rootgrow Ericoid mycorrhizal fungi
This specially adapted Rootgrow™ mycorrhizal fungi will boost the growth of acid-loving plants like rhododendrons, azaleas, heathers and blueberries.
It contains ericoid and arbuscular mycorrhizal fungi, which are found in poor acidic soils where ericaceous plants naturally grow.
Only £7.50
![](https://www.burncoose.co.uk/site/img/products/squaremedium/empathy-allpurpose_6208.jpg)
Fertilisers & Feeds - Empathy
All-purpose Seaweed Stimulant
All-purpose organic concentrated seaweed feed that is a ready to use, derived from sustainable harvested kelp, that can be used on all outdoor and indoor plants, except acid loving plants.
Perfect used in conjunction with Rootgrow™.
Only £7.50