Subterranean Clover
Trifolium subterraneum
Family: Fabaceae or Leguminosae
What it is like
Trifolium subterraneum is a ANNUAL growing to 0.2 m (0ft 8in). See above for USDA hardiness. It is hardy to UK zone 8. The species is hermaphrodite (has both male and female organs) and is pollinated by Insects. It can fix Nitrogen. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils, prefers well-drained soil and can grow in nutritionally poor soil. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils. It cannot grow in the shade. It prefers moist soil.
Height (m): 0.2
Where it is found
Sandy and gravelly pastures, also on cliff tops, avoiding acid soils and shady positions.
Southern and western Europe, including Britain.
Conservation Status:
Countries/locations it is found in
How it is used
Food
Rating: 1
Leaves - raw or cooked.
Medicine
Rating: 0
Other
Rating: 4
This plant can be grown as a ground cover green manure under tomatoes in the greenhouse. The seed should be sown before planting the tomatoes. It can also be sown under soft fruit and cut once or twice in the summer. Nitrogen Fixer.
Green manure: Fast-growing plants that can be used to increase the fertility of the soil.
Dynamic accumulator: Plants that gather minerals or nutrients from the soil and store them in a more bioavailable form and in high concentration in their tissues. Used as fertilizer or to improve mulch.
Food Forest: Plants for Edible Forest Gardens and Food Forests.
Nitrogen Fixer: Plants that fix nitrogen in the soil
How it is grown
Succeeds in a moist, well-drained circum-neutral soil in full sun. Succeeds in poor soils. Plants are partially winter hardy. After flowering, the fruiting head grows into the ground, thereby planting the seed. This species grows well in an apple orchard, the trees will produce tastier fruit that stores better. It should not be grown with camellias or gooseberries, however, because it harbours a mite that can cause fruit drop in the gooseberries and premature budding in the camellias. 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. Buttercups growing nearby depress the growth of the nitrogen bacteria by means of a root exudate. 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.
Propagating it: 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.
Best place to grow: Cultivated Beds;
Habit: Annual
Hardiness: 7-10
Growth:
Soil: Light (sandy), medium, heavy (clay)
Shade: No shade
Moisture: Moist