Trifolium obtusifolium

• Clammy Clover

Pre-soak the seed for 12 hours in warm water and then sow in spring in situ.

If the seed is in short supply it might be better to sow it in pots in a cold frame. When they are large enough to handle, prick the seedlings out into individual pots and plant them out in late spring.

Division in spring.

We have very little information on this species and do not know if it will be hardy in Britain, though judging by its native range it should succeed outdoors in most parts of the country. The following notes are based on the general needs of the genus.

Succeeds in a moist, well-drained circum-neutral soil in full sun^[5]. Succeeds in poor soils. It grows well in an apple orchard, the trees will produce tastier fruit that stores better^[6]. It should not be grown with camellias or gooseberries because it harbours a mite that can cause fruit drop in the gooseberries and premature budding in the camellias^[6].

This species has a symbiotic relationship with certain soil bacteria, these bacteria form nodules on the roots and fix atmospheric nitrogen. Some of this nitrogen is utilized by the growing plant but some can also be used by other plants growing nearby^[5]. Buttercups growing nearby depress the growth of the nitrogen bacteria by means of a root exudate^[6]. When removing plant remains at the end of the growing season, it is best to only remove the aerial parts of the plant, leaving the roots in the ground to decay and release their nitrogen.