How to grow Alchemilla mollis common name Lady's mantle
Alchemilla mollis, common name Lady's mantle, is an easy to grow herbaceous perennial, fully hardy and which will grow successfully in many conditions. The preferred growing conditions for Alchemilla is damp soil with some sun, but it is a vigorous plant which will survive in most conditions. This means it will tolerate semi shade, any aspect, exposed and sheltered spots, which makes it a useful plant for awkward areas. It will also grow in damp areas as long as they are not boggy. The most common variety on sale is A.mollis, a good variety with the RHS award of garden merit, always a safe bet when choosing a plant.
When it first comes into leaf and Alchemilla makes a fresh mound of zingy lime green foliage, which is very attractive, especially with raindrops as seen in the image. The leaves are almost downy in appearance and hold the water well.
Alchemilla mollis is one of those plants, like Hostas, which looks good in the rain. Flowers are formed on sprays, with multiple flower heads. When the flowers first emerge, they are a strong lime green colour which becomes a mass of tiny yellow flowers from early summer onwards. This variety grows to around 60cmc and makes good at the front of borders.
Alchemilla mollis look good with many plants, especially good with Allium cristophii and the lime green foliage looks good with purples and blues. One advantage of growing Alchemilla with Alliums, and why it's such a good companion plant for Alliums, is that often the leaves around the base of Allium look tatty even before the plant has flowered. It's one of its shortcomings. Plant Alchemilla around the Alliums and it will cover the base leaves of the Allium.
Alchemilla also looks good as a contrast growing around the base of a Cotinus "Royal Purple", the strong lime green contrasts with the purple. The contrast is good, but to be aware a Cotinus is potentially a large shrub, 3 meters plus, although it can be kept in check by pruning. Alchemilla also looks good combined with the soft blue of Nepeta (Cat Mint) a nice mix of blue with lime green/yellow and both flowering in June.
I have also seen Alchemilla planted to good effect growing at the base of a copper beech hedge and Alchemilla looks good along a path.
Alchemilla mollis is a simple plant.It is easy to grow, unfussy about its conditions and although a number are listed in the RHS Encyclopaedia of plants, you really only see A. mollis for sale.
A downside to growing Alchemilla Mollis - It is vigorous and self seeds
Be brutal and cut it back
Towards the end of the growing season, when you can physically see the spread of Alchemilla, take the knife to it. The Alchemilla in the image was flowing all across to the bark path before I cut it back. It forms very tough clumps and I keep an old bread knife for tough perennials and hack it back to a neat line, keeping it in check.
This stops it taking over areas of the garden and neighbouring plants. Do not worry, it's so vigorous you will not kill it.
Cutting back Alchemilla around July
Alchemilla comes into leaf early in the year, which means it can look tired by July, with brown spots and fawn areas marring the foliage, as in the images below.
A simple solution is to take the shears to it; either a complete haircut or cut it partially in stages and new clean foliage will be up and sprouting within a couple of weeks and look good for the rest of the growing season. It will not flower again, but it will produce fresh looking foliage.
To illustrate how quickly it grows back, and encourage the bold gardener in you, look at the images below. The first shows the Alchemilla in full bloom looking great, and then some weeks later when the foliage and flowers are looking tired and brown. I cut it back and within a short period, about 2.5-3 weeks, it had re grown some new fresh foliage, as in the third image.
Alchemilla mollis is very easy to grow, too easy and can be invasive.