There are over a hundred varieties of plums currently growing in Canada. Some of these are commerical, others are experimental and of course most are in our own gardens. Plums are adaptable and hardy, making them the second most popular fruit to grow (next to apples) in Canadian gardens. But, as with any plant or fruit, we must keep a close eye to make sure it’s growing properly and healthily. The fungal diseases black knot and brown rot are fairly common on plums.