I am interested in companion plants, cover crops, climbers, or bushes under pomegranates, red maple, and quince which my parents have in their yard? What would be good to plant underneath? Currently the trees have raw earth underneath and then grass around a circle of the tree. The house is in a Mediterranean continental climate, in Madrid, Spain.
Here's my take. Start with clovers of different varities that grow well in your area. As many types as you can get as they will come and go with seasons and conditions. Comfrey is always welcome in an understory as is yarrow (comfrey needs moisture). The quince will appreciate tansy as it deters ants that can spread sooty mold. If borer is a problem then the trees will benifit from lavender grown through the lower branches. There is a start.
Garlic growing under quince improves the flavour of the fruit apparently. Here is a list of things I have researched as being useful underneath quince trees Mixture of Garlic, marjoram, fox gloves, apple mint, nasturtiums, chives, wall flowers, tansy, lovage, stinging nettles, chamomile, alfalfa, white clover and rosemary. I have 2 quince trees so far with some of these under each. I'll add more as I get the time.
