Rare plants

Question: where can I find a rare plant to grow?

I have a rather complicated question ... from experts ...
Taking inspiration from the idea of ​​Mister Planet
I decided to cultivate a more or less rare plant that can easily survive without suffering on my balcony (maybe not in winter) ... I live in Varese and the balcony is facing West - South-West and in front has only a grove and the lake ... no building that can make shade in the afternoon until sunset ... What plant would you recommend?

Rare plants: Answer: rare plants

Dear Luca,
thanks to you and to Mister Planet, who are suggesting an activity that costs us little but that can do a lot of good for the planet; we often hear about biodiversity, but just as often we are not told what it is, or how useful it can be for our planet. If this were not the case, there would be no other motivation than the fully approved gardens, vegetable gardens and orchards. Unfortunately in the nursery the same plants are more or less always spread, not because nurserymen and plant producers do not care about the future of life on earth, but simply because we customers are content to cultivate the simplest and most decorative plants, which possibly not requiring great care. And so, in this way, we all have the beefsteak tomatoes in the garden, or the "smooth round", on the balcony we all have at least one vase of "Parisian" geraniums, and in the orchard we grow beautiful "Williams3" pears. Not that there is nothing wrong with our behavior, but over the years we are witnessing a proliferation of insects and fungal diseases, increasingly tenaciously resistant to insecticides and pesticides, also because the most widespread plants are always the same, and they are also particularly affected by the exact same pests.
Fortunately, there are those who take biodiversity to heart, that is the set of all genetically different living beings, with all the possible variables. The more biodiversity of a place is rich, the more the ecosystem is vital and able to regenerate itself in the event of an external attack.
One of the most important Italian realities in the field of biodiversity is located in the botanical garden of Lucca: the A.Di.Pa; or association for the spread of plants among amateurs. It is an association that every year spreads among its members hundreds of different species of plants of all kinds, through their seeds. These are rare plants, or little widespread, but also of particular cultivars, or of old horticultural varieties now forgotten almost everywhere. In addition to this, the seed band of this association is in contact with other global databases, with which they carry out (where possible) exchange of seeds of various kinds; therefore it is always a joy for the members to choose the 25 annual sachets of flowering plants, trees, fruit trees, and vegetables. In addition to this fairly large reality, there are local realities; in more and more nurseries seeds and scions of plants that were once typical of a certain region are gathered, but that by now no one cultivates anymore, with the purpose of spreading the cultivation again. Try to get information in the area where you live. There are also events and fairs specifically dedicated to this type of plants.