Mirabilis jalapa is a plant I have come to love, and I have the Chelsea Physic Garden to thank for it. When we first came to the garden, this plant appeared all over the place and was pretty rampant. I had never seen it before, and being a bit overcome with the scale of the gardening job facing me (whilst working, travelling to the UK, three children and all that) I ripped as much of it out as I could, reckoning that I needed to get on top of it. And I continued systematic destruction most years, but it always came back and bit me on the backside.
An embarassing number of years passed with me making no effort to discover what it was, and then, I was horrified to visit the Chelsea Physic Garden and see it growing in splendour there. Not only that, but I discovered that the cultivation of this plant dates back to certainly 1596, and probably before, as an introduction from Mexico via Spain, when it was considered to be the most desirable plant to have in your garden by the cognoscenti. Dr. Alice le Duc, of Duke University, North Carolina, has studied the plant closely, and recorded that Thomas Jefferson grew it at his garden in Monticello. Nowadays, it no longer grows in the wild in Mexico. I was mortified by my thuggery.
Standing aside from my ignorance for a moment, and just considering it as a garden plant, it has a tremendous amount to recommend it. First, it flowers reliably and non-stop for about 6-8 weeks at the back end of summer when it’s easy for the garden to be a little on the bare side. Then, apart from the yellow that I have, it also flowers in a deep cerise pink, which is stunning coupled with the fresh, green foliage. Wise people say that it also flowers in several colours on one plant but I have never seen this. It will grow in full sun and some shade, although if in full sun, it will do better in an area with some moisture. Having said that, in very hot summers, it dies back with me and then re-appears when the rain returns. Some say it has a scent, but I have to say my nose failed me again here.
It is a tall, slightly rangy plant, loosely growing upwards to about 1.5m with me, easily flattened by heavy rain, so needs positioning between other plants that will help it to stand up, or staking. I go for the former, as it fills in late summer gaps really well. In the UK, you might have to bring it in, like a dahlia and store it somewhere dry and cool, but you could probably pot it up and treat it like an overwintering geranium. The RHS has it as an annual, but this plant can be much more than that if you take a little care over the winter.
With me, the corms survive where they are in soil, but they do start later for me probably. It self seeds, so you can let it do that, or take seed, as I have from a neighbour who has the cerise-pink variety, and grow them on, the seeds germinate and roar up into substantial seedlings in late summer or early autumn, which you can just overwinter as above.
N.B. Label the pots, another weakness of mine, as the baby corms do an impressive imitation of being mud clots, and I have thrown plenty away not realising they were there.
It really is a pretty bombproof plant, and once you have got it going, it will stay with you for years. Think about it, you will be growing something that was an Elizabethan delight, and had been in cultivation for 200 years before Linnaeus catalogued it in 1753. That’s pretty impressive.