It can be hard to define exactly what is a weed and what isn’t. For some people, It’s easy – a weed is a plant growing where you don’t want it to. There are, of course, some weeds that you do not want growing anywhere – old man’s beard, oxalis, convolvulus – but there are some plants that straddle the line between being a desired inhabitant of the garden and being a little bit too adventurous with seeds or rhizomes.
An example – I love granny’s bonnets in the spring. They flower at the same time as irises and nicely fill up spaces in the garden. But they also seed themselves generously, so last year, I assiduously removed most of the seedheads, thinking only a few would flower this year.
And it worked, with fewer plants, but it also didn’t work, as many of the attractive shades I like did not appear this year.
And it definitely did not work in the limestone chip path at the back of the border. A blue-green haze has appeared with hundreds of small aquilegia seedlings, each with a strong tap root, meaning I have to scrape through the chips to remove the seedlings. Still, it’s a good way to see that part of the garden from the ground up.
Alstroemerias have become increasingly popular in recent years, and they seem to fit that middle ground too – they are often exquisitely beautiful and are reliable perennials, but they are also inclined to be a little bit ambitious about where they should be growing.
When I first started gardening, the only ones commonly available were the yellow and orange forms of A. aurantiaca. With willowy growth, they reached about 1.5 metres high, with bright flowers in the yellow-orange spectrum, often deeply shaded with brown or purple spots. They were attractive summer flowering plants, inclined to wander around a bit but not at all weedy.
Their cousin, A. psittacina has smaller growth and tubular flowers of bright red tipped with green – an unusual combination. I planted this once, and quickly found that it was looking at the rest of the garden the same way Russia looks at Ukraine.
Fortunately, I was able to repel its invasion and excised it from the bed. Others have not been so lucky, and this plant is now declared as a weed in many warmer climes.
About 25 years ago, we started to see dwarf forms in an expanded range of colours come onto the market. My first two were both from the ‘Inca’ series – a red and a yellow form. They are both great plants, with yellow probably being the better flowering form as it is slightly more compact.
Both varieties are growing in contained beds, but both have spread through most of the bed and are trying to escape into the lawn. I dig them back every couple of years, and it keeps them under some form of control.
At one stage I tried to remove the yellow one, but quickly found that any small piece of tuber left in the soil resulted in the plant reviving itself. It is pretty, and it is good ground cover, so I have become philosophical about never being rid of it.
There is another cultivar in another bed, this time a taller-growing one that looks like a brighter form of those I knew years ago.
The garden belonged to one of my sons, and he wanted to plant this bright plant in his garden. He left home years ago, and the garden has reverted to my ownership – it has peonies and iris in it now – but the alstroemeria lives on despite my efforts to remove it.
I am not suggesting you should not plant these South American beauties – just that you should be careful. If you have an area that requires some mildly aggressive groundcover, some alstroemerias may well be just what you are looking for.
A gardening friend had a mass of an apricot form growing through some French lavender, and when they flowered together, the effect was stunning.
However, I think I would be a little cautious about planting them in a warm spot with free-draining soil, as they might get away on you a little. Keep them in a container [the smaller varieties look fabulous is a pot] or in a small garden bed where it will not matter if they get a bit vigorous.
If you are digging any aggressive cultivars out, be careful about how you dispose of the tubers.
They have become serious pests in some places in the world – our Australian cousins have declared some of the noxious weeds, and I am sure some of the older cultivars in particular may be a threat to native plants if they are just disposed of on the roadside.