There’s snow on the garden and I’m deep into 2013 seed and plant catalogues. There are so many new plants on my must-grow list for the coming spring, and one that surprised me is ‘Pipolina’ micro clover (Trifolium repens ‘Pipolina’, from oscseeds.com).
Every spring I throw some white clover seed onto the lawn, where it grows well on clay loam soil, in bright sun and semi-shade. Clover thickens the turf, feeds the lawn by fixing gaseous nitrogen into solid form in the soil, and stays green when lawn grasses are temporarily brown during summer droughts. It withstands foot traffic, gets cut along with the lawn grasses, and reduces thatch buildup, which is the result of excessive fertilizer application. Lawns with 10 to 20 per cent clover content can get by with one fertilizer application in fall.
The white clover I’ve been growing is Trifolium repens, sometimes known as Dutch white clover, or ladino clover. Left uncut, it would stand about eight inches (20 cm) tall, and spread out into mats over the soil by prostrate stems that act as rooting runners. Its white flowers are a good nectar source for pollinators, although regular mowing prevents flowers from forming.
Hybrid ‘Pipolina’ white clover is shorter, reaching only four to six inches (10 to 15 cm) tall, has smaller foliage and seldom flowers. This miniature clover has all the usual advantages as a companion to turf grass, but less visual presence. For fastidious gardeners wanting to see a consistent greensward, the small leaves of ‘Pipolina’ are less visible mixed among the lawn grasses. But I can think of other uses for this micro clover, particularly as a surface for garden paths, in shrub borders, or even as a lawn substitute where mowing is infrequent. The low flower production would keep the clover turf from becoming a Mecca for honeybees (apologies to all pollinators), consequently there would be no fear of bee stings. If used as a groundcover for paths (perhaps in a vegetable patch), thorough edging once every growing season would eliminate any colonies that spread beyond their intended space (although you might be glad to keep them). As flowering is infrequent, there would be little spread from seeds.
One unexpected advantage to clover in the lawn has been its effect on rabbit diets. My family enjoys watching rabbits in the garden, and fortunately the bunnies ignore ornamental perennials in favour of the clover. Since strong colonies of clover have been established in the lawn, our resident rabbits dine exclusively on clover leaves. They never destroy the crowns of the plants, thereby ensuring foliage regeneration and more delicious meals. (Previous to the clover presence, the favoured rabbit meal was perennial geraniums.) Considering all the benefits of using ‘Pipolina’ clover as a companion plant to turfgrass, that’s a lot of value coming from a miniature plant.