Reliable, easy and pungent, these often maligned annuals deserve a bit of respect

I am aware that I have skipped a few annuals that I should have mentioned, including salpiglossis, but I can’t find a picture and, to be honest, they struggle a bit here and, gorgeous though they are, they suffer in damp weather and give me sleepless nights. So I will plunge straight into the next letter of the alphabet with a massive group of annuals, the tagetes.

Now, although we tend to use the word as the common name of the small-flowered and delightful Tagetes signata, tagetes is the botanical name of French marigolds (T. patula – above) which as you would expect, don’t come from France and African marigolds (T. erecta – below) which have absolutely nothing to do with Africa. All are native to Central America, especially Mexico. But they have become widely planted around the world, valued for their ease of growth, bright flowers and culinary and medicinal uses. Although there are other species, none need bother us except T. minuta (which is actually huge, though the flowers are tiny) which I will deal with later.

Robinson liked them, saying of French marigolds ‘ a charming summer annual of more varied colour’ (than African marigolds) ‘ there being many varieties striped, mottled and coloured with yellow, orange, chestnut, and other hues.’ He does deal with the elephant in the room ‘The unpleasant odour unfits them for cutting.’ All tagetes have a distinct smell when rubbed or the stems are broken and I know that some people won’t grow these plants because of it. Personally I find it mildly pleasant and just a sign of the season. It is pungent and has a sweaty base note but it certainly would not stop me from growing them. For the easily offended there are strains that are alleged to be less strongly aromatic.

To make things easy, in general terms, African marigolds are the tallest, often as high as 75cm, with the largest flowers, in shades of yellow, gold and orange, though breeders have worked hard to create white flowers and creamy ‘Vanilla’ has been achieved. They have also dwarfed them and they can be as short as 20cm – these make me shudder with horror.

Unless you buy F1 hybrids and good strains there will be a proportion of single flowers – with a central tuft of disc florets and a ring of broad ray florets. I don’t know if I am alone in this but I find them really ugly. The more popular double flowers (I don’t think you can deliberately buy the singles*) are packed with ray florets and are dense. They are the typical wildlife unfriendly plant that people love to hate, useless for pollinators until they start to fade and the centre opens up to allow an exploratory proboscis access. There are looser, chrysanthemum-flowered kinds that have narrow florets and a rather scruffy look.

The problem with African marigolds is that the flowers are so densely packed with petals that they collect water and too often in this climate they rot. In summer this is tolerable and the heads can be snapped off but as cool and damp becomes the norm, in autumn, plants can be a mess. It seems a particular problem with the very dwarf, over-bred kinds. The browning is not so much of an issue with the orange flowers but shows up more in the lemon yellows and is awful on the vanillas.

• It appears I may be alone in disliking the singles. I see that Thompson & Morgan sell ‘Daisy Wheel Lemon’  – but not to me they don’t.

It will come as no surprise that I prefer the older and taller kinds. Though they do usually include some ‘ off ‘ kinds and are almost straggly, the frankly cheap ‘Crackerjack’ mix has much to like, and it is the one I grew as a child. It was probably as tall as me, at 90cm, and we grew it with kochia (burning bush), another annual I missed mentioning but which I am growing again this summer.

I also like the astonishing ‘Kees’ Orange’ (above). Apparently the breeder was determined to produce the most ‘orange’ marigold possible and this one certainly makes the others look like bland satsumas against this vibrant Seville orange. Obviously such a harsh colour can be hard to place and last time I grew it I combined it with red cabbages. I think that steely and purple, metallic foliage sets off the shade perfectly.

French marigolds are much more varied, but have suffered from being shrunk too. Some are only 12cm tall but most are 15-25cm which makes them perfect for the front of beds and containers. I am delighted to say that seed companies are being more adventurous in what they stock and there is now a good number of taller kinds available, making mounded plants 60cm high with masses of small flowers. I think the trend for these arose from the reintroduction of the ‘Scotch’ striped marigold in the 90s. This was preserved by keen gardeners and is a tough, wiry plant with single blooms striped with mahogany and yellow. It is a great plant. As might be expected, the colourway was added to the short kinds – somehow rather wrong to me – more tall kinds have seen the light of day, including the rusty red ‘Burning Embers’ (confusingly called the Swedish marigold because it originated at the Linnaeus Garden, Uppsala, Sweden) and  the rather similar ‘Cinnabar’.

But most French marigolds are dwarf and double. They are roughly divided into the crested kind with a ring of ray florets around a centre of enlarged disc florets (below), and the carnation-flowered with fully double flowerheads, plus of course the singles. Like all marigolds, they are easy to collect seeds from but some hybrids are sterile, including the triploid, Afro-French hybrids which are robust, colourful and need less deadheading, but you can’t collect seeds from these.

I like the singles, including the old ‘Naughty Marietta’, though stocks are not as good as they were and you often get ‘off’ plants, and the old, 30cm high, ‘Legion of Honour’ introduced in 1894 (photo top of page). Even the doubles usually display their wares to bees and butterflies eventually so these really are good wildlife plants. What is extraordinary about French marigolds is that they are so weather resistant. No matter what the weather is like; blistering heat or miserable rain, I have never seen French marigolds looking bad at any trial ground I have been to. While the spent flowers will go mouldy on plants in wet weather, the blooms themselves always look OK and the plants soldier on. They are wonderfully reliable. But there is one problem – that although we may not like the scent of the plants, slugs and snails can sniff them out like a pig finds a truffle. So, immediately you have cleared the soil of spring bedding and weeds and have carefully planted out you marigolds, protect them from slugs.

The range of colours includes pale yellows and the richest mahoganies. The most interesting colour break was a few years ago with the introduction of ‘Strawberry Blonde’ (below).  I have written about it before because when I saw it on a trial ground I was really captivated by it and I still love it.

And that leaves us with Tagetes signata or, simply, tagetes. This charming little plant has a much finer and bushier habit and smaller, single flowers. It is usually grown as the golden or lemon yellow varieties but there is also the multicoloured ‘Paprika’ strain. I prefer the lemon yellow and it is such a wonderful, bright flower. It tends to flower itself to death and is not as long-flowering as the others. I often plant it beside onions because it can be pulled out by late August when the onions need to be lifted to dry off. But, perhaps more importantly, this and the other tagetes are alleged to have many valuable properties.

All tagetes are edible and the petals of African marigolds are used as a food colouring. The dried flowers of African marigolds are even fed to hens to improve the colour of their yolks. They are frequently planted as companion plants, especially with tomatoes because they are supposed to discourage whitefly. I have always been slightly sceptical of this because, when I was a student at Kew I had to look after a huge collection of tagetes grown for research and, as I passed between the plants, I almost choked on the clouds of insects that flew off the plants. But many people will continue to plant marigolds between their tomatoes.

The roots also secrete chemicals that kill nematodes and may have anti-bacterial qualities too, which is a reason why you should not plant them among beans and peas, which have nitrogen-fixing bacteria on their roots. Look at any travel programme about India and you will see the flowers of African marigolds draped, scattered and flung everywhere. But the Aztecs were using them long before and they are still used extensively in Mexico in ceremonies. Decades ago when I went to Thailand and supposedly visited a village where Opium was grown, my fellow tourists were delighted to see all the African marigolds – I was less convinced.

There is so much to say about these plants and this post is too long already. Suffice to say that they are half-hardy annuals and must be sown in heat in March or April and planted out in late May. They germinate in a week at 20c and the long seeds (actually fruits or achenes) are easy to handle – just give them a bit of elbow room and don’t sow too thickly.

They bloom quickly. French marigolds are usually in bloom before they are planted out. Deadhead them to encourage flowering and prevent seed production until the end of the season if you want to collect your own seeds. The seeds are large and germinate quickly.

Oh yes – Tagetes minuta (below). This is frequently grown specifically to rid soil of soil pests including nematodes. It is a large, bushy plant and I have grown it when it has been 2m high. It has small, dull flowers and seems to bloom late. It is no beauty but is interesting and would make a good summer screen.

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