How to grow Bidens
Bidens is a large genus of around 200 species, including annuals, perennials, and deciduous shrubs found growing throughout the world. This growing guide will focus on the cultivation requirements of the species most likely to be grown by gardeners in the UK – Bidens ferulifolia.
Bidens ferulifolia is a short-lived perennial native to southern USA and Mexico, popular for its tough, undemanding nature and long-lasting profusion of brightly coloured, daisy-like flowers. As borderline hardy it tends to be treated as an annual in frost-prone climates such as ours.
Key Information
Position
Soil Conditions
Hardiness
Where & when to plant Bidens
Our bidens plants are available from early spring. If they arrive before the last risk of frost has passed in your area (generally around mid to late May), pot them up and keep in a cool, frost-free environment such as an unheated conservatory or greenhouse until it is safe to move them outside.
Some Bidens ferulifolia have an upright growth habit and are suitable for the front of a border, while others have more of a trailing habit and are intended to tumble over the edge of containers, hanging baskets, window boxes, and walls. Whatever the situation, ensure your bidens has a sunny spot. It can cope with wind, drought, and a certain degree of neglect. The perfect annual bedding plant!
How to plant Bidens
In a container
- Pinch out the growing tip of your plant, snipping it off just above a slightly lower set of leaves. This will encourage it to become bushier and more floriferous.
- You may wish to grow your Bidens ferulifolia in its own pot or use as the ‘spiller’ component in a ‘thriller, filler, spiller’ mixed container.
- Choose an appropriate container. The eventual size of Bidens ferulifolia can vary, so do check individual descriptions for details. Ensure there are plenty of drainage holes in the bottom.
- Use a good quality potting compost with plenty of horticultural grit mixed in, and, if not already present in the compost (check the description on the bag) some slow-release fertiliser granules.
- Start by partially filling the pot with compost; enough so that when placed on it the upper surface of the root ball is about 3cm lower than the top of the pot.
- Infill all the space surrounding the root ball with compost, firming down with your fingers then adding a little more so the plant is held tight.
- Pick up the pot (if you can!) and lightly tap on the potting bench or ground a few times to help further settle the compost around the plant.
- Soak well with water.
- A mulch with horticultural grit will look attractive and help to prevent a ‘cap’ or crust forming on the top of the compost (something container plants can suffer due to the artificial nature of their watering).
In the ground
- Pinch out the growing tip of your plant, snipping it off just above a slightly lower set of leaves. This will encourage it to become bushier and more floriferous.
- Clear the chosen area of weeds.
- Dig a planting hole several times larger than the root ball. It is a good idea to mix in some horticultural grit and well-rotted organic matter at this stage (though not essential).
- Place the plant in the hole, ensuring the top of the root ball sits level with the surface of the soil. Too low and the plant may rot, too high and the roots can dry out.
- Backfill with soil and firm in gently with your foot.
- Soak well with water.
- Mulch around the base with well-rotted organic matter.
What to plant with Bidens
A large container or tub packed with mixed planting is hard to beat, though achieving a harmonious, balanced combination can be harder than it looks. Why not try our current favourite of bidens with phormium, thunbergia, Verbena rigida, artemisia and petunia. A stylish riot of summer-flowers and foliage awaits!
Alternatively, you may wish to use your bidens as annual bedding in a border. The often-fiery colouring of this plant goes spectacularly well in a hot planting scheme, along with plants such as canna, cosmos, achillea, crocosma, zinnia, and Mexican/ Californian species of agastache (which offer reds and oranges, as opposed to the more well-known purple and blue species).
How to care for Bidens
Pruning and Deadheading
Deadhead regularly to prolong flowering.
Watering
In the ground: water until established, after which this drought tolerant plant tends to look after itself.
In a container: water regularly throughout the growing season, allowing the top few centimetres of compost to dry out between soakings.
Cold Protection
Bidens ferulifolia will not tolerate temperatures below 0°C. As a short-lived perennial, even if you were to overwinter it in a frost-free environment its subsequent performance is unlikely to match the first year in vigour and flowering. Bidens ferulifolia is therefore generally treated as an annual, meaning it is removed to the compost heap at the end of the growing season.
Pests and Diseases
Bidens ferulifolia tends to be trouble-free.
How to propagate Bidens
Perennial bidens can be propagated by cuttings in autumn.
- Find non-flowering shoots 5-10cm long and snip off the plant.
- Put them in a plastic bag straight away to prevent drying out.
- Fill a container with a compost mix which is at least 50% perlite (or if you prefer, as we do, 100% perlite).
- Remove the lowest third of leaves.
- Insert the cuttings into the compost and water lightly. Several cuttings can be put in the same container if there is enough space to do this without them touching.
- Place in a greenhouse or propagating unit if you have one or covered with a plastic bag on a windowsill if not (out of direct sunlight).
- Keep the cuttings misted and occasionally watered until they root. You will know this has happened when roots emerge out of the bottom of the container.
- Gently remove rooted cuttings and pot them into individual pots. Grow on in an unheated yet protected environment such a conservatory, greenhouse, or cold frame until they are ready to be planted out the following May.
Common Bidens questions
- Is bidens perennial?
The species in question (Bidens ferulifolia) is a short-lived perennial, usually treated as an annual. See ‘Cold Protection’ section above for more information. - Does bidens need deadheading?
This is not essential, though will give flowering a boost (more and over a longer period). - Is bidens trailing?
The straight species of Bidens ferulifolia has an upright form, though many of its cultivars have been bred for a trailing habit. Check individual plant descriptions for details.