Red-hot poker: planting, propagating & overwintering Kniphofia

Red-hot pokers are vibrant, sun-loving plants that make a great focal point in any garden. Discover this stunning bee-friendly perennial and get tips on planting it in your own garden.

Red-hot poker plants (Kniphofia) have vibrant red blooms that look like torches glowing atop the bushy foliage. Their nectar, which is used in creams and ointments and is also fit for us humans to drink, makes them popular with bees and butterflies. Read on to find out everything you need to know about red-hot pokers and discover some of our favourite Knifphofia varieties.

Red-hot poker: origin and characteristics

Red-hot pokers, also known as torch lilies, are members of the asphodel family known as Asphodeloideae, of which aloe vera is a popular member. Being native to Africa, red-hot pokers’ natural environment offers them a Mediterranean climate under full sun. From the coast up into the mid and high mountains, red-hot poker flowers thrive on rugged slopes and river banks. In the colder months, these plants stand in wet soil that gets plenty of fresh oxygen. In summer, the hotter temperatures cause the moderately nutritious silicate rock to become quite dry. In their native habitat, red-hot poker plants’ main growing period is in the wet winter and spring. In the hot, dry summers, they go dormant. However, in our part of the world, red-hot pokers flower in summer.

These herbaceous plants form horizontal rhizomes which help them to survive. They are thus perennials. While some species are evergreen, in many species the above-ground parts of the plant die back in winter.

Red-hot pokers are clump-forming perennials, meaning the narrow, long and keeled foliage leaves grow closely together in clumps. The shoot axes, on which several intensely coloured flower corollas are located, usually protrude from these to a height of around 1m. The flowers on these 15 to 30cm long clustered flowerheads are usually red at the top and turn yellow towards the bottom. However, they can sometimes be white, green or apricot. Red-hot pokers flower between June and October, depending on the variety. As the flowers unfold from the bottom up, the flowering period lasts for quite a while.

Red-hot poker species and varieties

There are currently about 150 known Kniphofia species. Breeding has also given rise to numerous hybrids and varieties. Here are some notable Kniphofia species and varieties:

• Kniphofia uvaria: this is the original red-hot poker species from which the present cultivar crosses originate. It has red to yellow flowers and grows from 50 – 120cm tall. There are different varieties of this type, such as ‘Grandiflora’.
• Kniphofia uvaria ‘Papaya Popsicle’: this variety blooms vigorously in salmon pink, fading to apricot, and grows up to 50cm high.
• Kniphofia uvaria ‘Ice Queen’: white flowering variety that grows from 100 – 120cm high.

• Kniphofia uvaria ‘Green Jade’: has flowers that fade from white to green, 100 – 120cm tall.
• Kniphofia hybrid ‘Royal Standard’: yellow, orange and red gradient of flowers, grows from 80 – 100cm tall.
• Kniphofia hybrid ‘Vanilla’: strong yellow flowers, grows from 90 – 100cm high.
• Kniphofia uvaria ‘Saffron Bird’: orange-pink flowering variety, salmon-pink to cream, grows to around 90cm tall.

• Kniphofia hybrid ‘Fire candle’: flower red and orange, grows from 60 – 70cm high.
• Kniphofia galpinii ‘St. Gall’: orange flowering variety that grows from 60 – 80cm tall. It is more frost hardy than other species.

Growing red-hot poker plants

The climate here in the UK is not ideal for these plants. Hence, red-hot poker plants growing here have to adjust their rhythm a bit and go with the flow, so to speak. As a result, they rest in winter instead of summer.

Where to plant red-hot poker plants

Red-hot poker plants are only winter-hardy to an extent and best survive the winter months in mild locations, such as in front of protected south-facing walls. The ideal place to plant red-hot poker in your garden is in a wind-protected location in full sun on very loose, well-drained soil. While a deep, well-draining gravel substrate is ideal, you can also adjust your existing soil to fit this plant’s needs. Simply loosen the soil in the area and mix in plenty of sand before planting. The soil should be moderately rich in humus and nutrients with a pH between 6.5 and 8. Ensure it is rather dry to fresh, but never allow it to dry out completely. Red-hot pokers need watering more frequently in the summer than in winter. Remember to ensure they get plenty of water during the main growing period. They will tolerate short dry spells if necessary, but this will lead to slower growth. To prevent the soil from drying out so quickly, mulch the area around the plants.

It is best to plant red-hot pokers in the spring once the risk of frost has passed around mid-May. These plantsoften fail to establish themselves when planted in autumn. After planting, you will still need to protect your red-hot pokers plants from frost, as they are not reliably hardy. In winter, they will not tolerate waterlogged soils and cold, unprotected sites at all.

When planting red-hot pokers in the bed, keep a planting distance of 60cm. This equates to about two plants per 1m². Aesthetically speaking, planting one to three plants (max. 5) per bed is ideal. Make sure the basal rosette, which is where the leaves sprout from the shoot axis, is close to the ground and parallel to the soil surface, but never below ground level.

Red-hot pokers have thick, yellow roots that bundle together and spread far out to the sides. To avoid injuring the root system, choose a location that will not need to be dug up regularly.

Summary – Red-hot poker’s preferred planting location:

• Plant around mid-May once the risk of frost has passed
• Full sun, preferably 6 hours a day or more
• Wind-protected location on warm south side
• Loose, well-drained soil that is moderately rich in humus and nutrients
• Ensure soil is dry to fresh and add a layer of mulch to prevent it from drying out
• Avoid digging around the plant to avoid damaging root system

Suitable red-hot poker companion plants

Large groups of red-hot pokers really make an impact from afar. They look wonderful planted amongst tall grasses or shrubs with attractive foliage. There are many companion plants to choose from, as long as they have similar needs in terms of location. Here are some examples of good red-hot poker companion plants:

• Grasses: pampas grass (Cortaderia selloana), tender feather grass (Stipa tenuissima)
• Flowering plants: bearded iris (Iris barbata), daylilies (Hemerocallis), montbretias (Crocosmia), palm lily (Yucca), ornamental onion (Allium), beardtongue (Penstemon), crimson beebalm (Monarda didyma), catmint (Nepeta cataria), mullein (Verbascum), lavender (Lavendula), Perovskia (Perovskia), dahlia (Dahlia), globe thistle (Echinops sp.), tickseed (Coreopsis), yarrow(Achillea), sneezeweed (Helenium), lilies (Lilium), gypsophila (Gypsophila)

Avoid planting red-hot pokers next to highly competitive plants such as aster (Aster), as these will keep your torch lilies from unfolding their true potential.

Growing red-hot pokers in a pot

As red-hot poker plants are sensitive to harsh winter conditions, planting them in a pot is better than planting in the bed. Pots can be quickly brought inside in winter and also warm up quickly in the spring. That said, pots have very limited space for red-hot poker plants’ roots, so you will need to opt for a nutrient-rich and structurally stable substrate. Our Plantura Organic Enriched Compost releases nitrogen over time and contains plenty of phosphate and potassium oxide which promote stable growth and attractive flowering. Create a drainage layer at the bottom of the pot to prevent waterlogging and mix some coarse-grained materials, such as expanded clay, sand or gravel, into the soil. A mixture made of 60% Plantura Organic Enriched Compost and 40% structural materials is ideal. Finally, add a layer of mulch on top to keep the soil moist.

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Plant one to two seedlings in a 1 litre pot, or two to three in a pot that can hold more than 2 litres. Larger containers will fit more plants. Allow the top of the seedling(s) to protrude a good 5cm out of the soil. Separate and pot up the seedlings individually the following year into 5 litre pots to avoid overcrowding. Full-grown red-hot pokers require large, wide containers with a volume of 20 litres.

Propagating red-hot poker plants

Red-hot pokerplants can be propagated from seed. After successful fertilisation, the plants produce seeds in small, green globular capsule fruits. After a while, these fruits turn brown and open, at which point you can harvest the seeds. Start red-hot poker seeds on the windowsill from February onwards. Red-hot poker seeds require cold stratification, meaning they need to be exposed to cold temperatures for a period of time in order to germinate. Store seeds at an average temperature of 5 °C for 6 to 8 weeks. Keep seeds you have collected yourself in a bag in the refrigerator until spring. 

Red-hot poker seeds also require light to germinate, so do not cover them with soil when sowing. Kept at temperatures of at least 15 °C, the seeds will start growing after about 2 to 3 weeks. Kniphofia seeds must not dry out under any circumstances, so keep the soil moist during this time. It is best to keep young red-hot poker plants in a greenhouse for their first year to protect them from slugs. You can move them outdoors from the second year on.

Summary – Growing red-hot poker from seed:

• Cold stratification: store in the fridge/at 5 °C for 6 to 8 weeks
• Start indoors from February or directly sow from April
• Do not cover seeds with soil
• Keep soil moist
• Temperature: 15 °C
• Germination: 2 – 3 weeks
• Keep in greenhouse for the first year (recommended)

Another way of propagating red-hot poker plants is by dividing the clumps. This can be done in April. To do this, first expose the rhizome, cut off the flower shoots completely and cut back the leaves to about 15cm. To encourage new shoots, trim the roots as well.

Now it is time to divide the clumps. If you plan on growing the resulting plants in a pot, you need small sections, about 5cm wide. If you want to plant them out in a bed, the sections need to be as large as possible. Using a sharp, clean knife, divide the plant, ensuring each section has several visible “eyes” i.e. shoots. To disinfect the wounds, dip them in charcoal powder and cover with a damp cloth to prevent them from drying out. Then, simply bury the rhizomes in planting holes in suitable locations along with some organic fertiliser. Make sure that the roots point downward and the shoots point upward.

Overview – Propagating red-hot poker by division:

• When: April
• Cut back leaves and flower shoots to expose the rhizomes
• Remove rhizome from soil
• For growing in a pot, divide the rhizome into 5cm-wide pieces
• For growing in a bed, separate rhizome into larger pieces (the larger the better)
• Plant rhizome pieces the right way up with a little flower fertiliser

Are red-hot pokers winter hardy?

Red-hot pokers are conditionally hardy. They are assigned to winter hardiness zone Z7 and, accordingly, can withstand temperatures of maximum -17.8 °C. That said, they do require some extra winter protection measures.

Torch lily flowers wither towards autumn but remain standing. Do not deadhead until the next spring, as the flowers provide a little protection over the winter. Leave the foliage as well, and tie it together loosely. Covering lightly with spruce branches, leaves or fir brushwood also helps to protect against frost. Do not allow moisture to accumulate under the cover, as this could lead to rot. Fertilising too much or too late into the year can reduce winter hardiness. Therefore, discontinue fertilising in autumn at the very latest.

Overwinter potted red-hot poker plants at cool temperatures of 5 to 10 °C in a light to semi-shaded spot. They will tolerate light night frosts. Discover some winter-hardy perennials to adorn your garden year around in our separate article.

Are red-hot poker plants poisonous?

No, red-hot poker plants are not poisonous, neither for humans nor for animals. They are perfectly safe for all to enjoy.

Interested in growing some red-hot poker plants in your garden? Visit our article on red-hot poker
care to find out what these plants need to thrive.