Ruth, I did this, myself, about 3 years ago, by harvesting seeds out of ripe guava fruit, following instructions I found on the web. Suggest you search on something like "germinate feijoa" . Essentially, we are to allow the seeds to sit in a dish, in their own moist, gelantinous surroundings from the fruit, in order to ferment, for a few days. Then allow the seeds to dry. In the spring plant them in pots, keeping the soil moist till they sprout. I was able to get 6 new plants.
One plant I gave to a friend, one to my mother, one to my brother. Theirs are all doing well. One seedling I planted here in my townhouse complex; it simply disappeared one day. Another I guerilla planted at the
local library, but it too disappered after about a month. The last one I planted at a park half a block away from me. This one I thought would die or disappear (because there is no
water from a sprinkler system there) but, in fact, it is doing well. I've had to take water to it several times over the summer but I took some mulch over there and every time I visit my plant I make sure any fallen leaves are drawn up around the little bitty so it has a nice blanket.
Also, I kept the dry seeds in a little plastic sleeve. As this plant is
native to relatively warm area, it does not need a period of cold, like in the fridge, in order to germinate. I live in Los Angeles and the South American guava thrives here.
