Alchemilla Lady's mantle
Growing Alchemilla mollis common name Lady's mantle
Alchemilla is an easy to grow perennial, fully hardy which will grow in many conditions. Alchemilla prefers damp soil with some sun but it is vigorous and a plant which will survive most conditions. The most common variety on sale is mollis, a good variety with the RHS award of garden merit so always a safe bet when choosing a plant. It makes a mound of green foliage as seen in the middle image, looks very attractive with raindrops on its leaves, ( in common with Hosta) and makes a mass of tiny yellow flowers from early summer onwards. This variety grows to around 60cmc and makes good ground cover in the borders.
Alchemilla mollis looks good with many plants, image on the above right is 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 Alliuma look tatty even before the plant has flowered, it's one of it's shortcomings. Plant Alchemilla around the Alliums and it will cover the base leaves of the Allium.
Alchemilla also looks good in contrast, in the image on the left where it is growing around the base of a Cotinus "Royal Purple" and yet to flower in the mix is an Allium. The contrast is good but be aware a Cotinus is potentially a large shrub 3 meters plus although it can be kept in check by pruning. Alchemilla looks good combined with the soft blue of Nepeta (Cat Mint) a nice mix of blues with lime green/yellow and both flowering in June.
A down side of Alchemilla is that it is a big self seeder which some gardeners may find a problem, but it's easy to weed out where you don't want it. I have seen Alchemilla planted to good effect growing at the base of a copper beech hedge and Alchemilla looks good along a path. Alchemilla comes into leaf early in the year and so can look tatty by July, with brown spots and fawn areas marring the foliage. An easy solution is to take the shears to it; either a complete haircut, cut it partially in stages and new clean foliage will be up and sprouting within a couple of weeks maximum and look good for the rest of the growing season. It will not flower again but it will produce fresh looking foliage.
This is illustrated in the images below, the first shows the Alchemilla looking sad, bit tired and brown I cut it back and within a short period of time it had re grown some new foilage.