Planting sunshine in your garden
We’ve had a lot of overcast, grey days this autumn – perfect to show off the dazzling oranges and yellows of the marigolds. African and French marigolds are among the easiest and least demanding of annual flowers and can cheer up a garden bed like nothing else.
African marigolds are the tall-growing type with large pom-pom flowers (Tagetes erecta). In their natural habitat, which is Mexico and Central America, they come in shades of yellow and orange only, but plant breeders have worked on our garden strains to produce some rather bland cream shades, as well as a number of hybrids with the French marigold.
Also native to Mexico, the French marigold (T. patula) is a short and dainty plant with smaller flowers. They come in a wider colour range, and have both double and single flowers. These are very popular seedlings with nurserymen because they can be forced into bloom when small, making them easy to sell to us!
The hybrids come in a range of sizes from about 30cm up to 90cm tall, with a good range of flower colours, petal arrangements and patterns. The one thing all the marigolds have in common is foliage politely described as ‘strongly aromatic’. This quality has led to a reputation as a nematode repellent, so some gardeners like to plant them among their tomatoes. Unfortunately, you will have to chop down and dig in the marigolds to have any effect – the repellent is the leaves, not the roots.
Serious nematode problems are better managed by practising strict crop rotation and by fumigating the soil with mustard plants. Grow a green manure crop of mustard (seeds available in bulk at the supermarket or health-food store) let it come up to flower and then dig it in. The rotting foliage will kill off the pests.