How to Grow Marigolds
‘Marigold’ means golden flower, and these vibrant blooms gleam brightly in pots and beds
all summer long, adding colour and attracting pollinators. Marigolds are easy to grow and
very rewarding, and their popularity with beneficial insects makes them a welcome addition
to any garden.
Different types of Marigold and how to identify them
-
There are several different plants that all go by the common name of marigolds, and they all
have slightly different growing requirements. Here’s how to recognize the most common
types of marigold: -
Pot marigolds (Calendula officinalis) are also known as English or Scotch marigolds.
They grow to between 30-60cm tall, and have bright yellow or orange daisy-like
flowers with long slender petals. -
French marigolds (Tagetes patula) are compact, growing to around 20-30cm tall, and
have broad, squarish petals with frilled edges. -
African marigolds (Tagetes erecta), also called Mexican or Aztec marigolds, are
generally tall, with some varieties growing up to 1.2m high. They have large, round,
brightly coloured pompom flowers.
Using Marigolds in companion planting
-
Pot marigolds planted in vegetable plots can act as a ‘trap’ crop, attracting aphids,
which then get stuck to their sticky leaves and stems. They also attract beneficial
insects like ladybirds and hoverflies, whose larvae eat large amounts of aphids. -
Marigolds’ colourful flowers bring in pollinators, which also pollinate nearby fruit
and vegetable plants, improving harvests. -
The scent of French marigolds is said to repel whitefly, so they are often planted
near tomatoes, especially in greenhouses. (However, see below regarding the effects
of French marigolds on nearby plants.) -
French marigolds can be used as a ‘trap’ crop to lure slugs away from other plants.
The slugs can then be collected and disposed of. - African marigolds attract hoverflies, whose larvae eat aphids.
-
NB: The roots of both French and African marigolds produce chemicals that can
inhibit seed germination and the growth of nearby plants, so plant them at a short
distance from other plants, or grow them in pots.
When your plug plants arrive
-
Unpack your plants immediately and check the compost to ensure it has not dried out in
transit. Water with a fine spray, or sit the plants in a tray of shallow water if the compost is
dry. -
Pot on plants as soon as possible (preferably within 24 hours) after they have had time to
settle.
Potting on and planting out plug plants
- Handle each plant by the plug root ball, rather than the stem to avoid damage.
-
Pot each plug into a 7.5cm (3in) pot using a good multi-purpose compost or a
container compost. -
Grow on for a few weeks in a greenhouse or a bright, frost-free place, but avoid
direct sunlight. -
Keep moist but do not over-water. If very cold weather is forecast, cover with a layer
of fleece. -
Once there is no more danger of frost, the plants can be moved to their permanent
position. -
Harden off your plants before planting them out by placing the pots outside during
the day and bringing them back in at night. After 7-10 days, the plants will be ready
to plant out.
How to grow pot Marigolds (Calendula Officinalis) from seed
- Sow pot marigold seeds indoors in a seed tray filled with moist seed compost. Cover
the tray with a clear plastic bag and place it on a sunny windowsill. Remove the bag
once the seedlings have germinated. - Prick out the seedlings once they are big enough to handle and pot on into individual
pots filled with multipurpose compost. - Grow on and plant out in April.
- Alternatively, sow pot marigold seeds directly outdoors from March onwards (they
will tolerate light frosts). Sow the seeds 0.5cm deep and 5cm apart. Thin the
seedlings out to 25cm apart.
How to grow French and African Marigolds (Tagetes patula and T. erecta) from seed
- Sow French and African marigold seeds indoors in early spring in seed trays filled
with moist seed compost. - Place the seed trays in a propagator at 21-24C, or cover the trays with clear plastic
bags and place on a sunny windowsill. Remove the plastic bags once the seedlings
have germinated. - Once the seedlings are large enough to handle, prick them out and pot on into
individual pots filled with multipurpose compost.
How to care for pot marigolds (Calendula officinalis)
- Grow on indoors and plant out after the frosts have finished. Plant pot marigolds in well-drained soil in full sun. They will grow well in relatively
poor soil. - Deadhead faded flowers to ensure a long flowering season.
- Pot marigolds are relatively drought tolerant, but keep an eye on them in dry periods
and water if needed, as they are more prone to powdery mildew in drought
conditions.
How to care for French marigolds (Tagetes patula)
- Plant French marigolds in full sun, in well-drained soil with plenty of well-rotted
garden compost or other organic material added. - Water regularly, especially in dry periods. French marigolds need more water than
pot marigolds or African marigolds. - Deadhead regularly to prolong the flowering period
How to care for African marigolds (Tagetes erecta)
- Plant African marigolds in a well-drained soil in full sun. They will flower best in
slightly poor soils; if the soil is too rich they will produce lots of leaves but fewer
flowers. - African marigolds are drought tolerant, but will need watering in very dry spells.
- Deadhead regularly to prolong the flowering period.
When your plug plants arrive
Marigolds may be prone to the following pests and diseases. Read more about how to
control common plant pests and diseases here
Pests
- Slugs and snails (especially French Marigolds)
- Aphids (especially pot Marigolds)
Diseases
-
Powdery mildew (African marigolds and pot marigolds)
