Mirabelle Plum Seeds

 Mirabelle plum is a wild French plum grown worldwide for its rich complex flavor used in jam and other processed fruit mixtures including pies, preserves and wine. Although commercial uses are centered around the French region of Lorraine, it is also found in Poland and the Czech republic where this plum was carried by those who found it as a wild population of alpine plums. Today large trees exist in the U.K. in some very out of the way places so it probably has been distributed for hundreds if not thousands of years carried by pits much like the peach was.  

Some online information has labeled it the illegal plum. In reality this species plum is not illegal to grow but like all species in the genus Prunus, it is illegal to import the seeds, fruit and plants.  It can be grown within the U.S. and is currently grown as grafted trees from a few other nurseries where named selections have been created. 

My Mirabelle plums have been producing now for 30 years. They came labeled as var. syrica from an arboretum collection as well as wild found trees in France, its country of origin.  My plants tend to be more like a crabapple tree in shape with asymmetrical branching.  Surprisingly  the fruit is similar to beach plum with different colors of red and yellow. Variety syrica is completely immune to black knot and has few insect pests or fungal diseases.  But in some years it has problems with plum curculio. This is probably it biggest pests. Older trees will begin to fade after 25 years and new sprouts near the trunk should be kept to take the place of the main trunk which will eventually die back to the root crown. Other suckers can be trained to maintain the root system. The tree itself is not particularly fast growing but in the right sandy soils with good drainage the trees respond to fertilizer very well and branches can be laden with fruit in good years. 

It needs full sun and a soil that is highly drained or sandy. Dense clusters of fruit form starting in years 4-6 from seed. Some trees took 10 years from seed to really set fruit. Our seedlings come true to type  and range from yellow to red. It does not appear to hybridize with the other plums I have as it flowers at a different time. The mixed types have a unique tart flavor which is highlighted when made into jam and syrups. 

Selection could be done on fruit color but for all practical purposes the fruits taste similar with only slight variations. The yields also appear to be about the same. The trees do appear to loose large limbs as they mature and are replaced by new suckers near the main trunk. My guess is this is a means for the plant to loose weaker limbs after fruiting many years and to replace them. The trunks can be cut to the ground then and restarted so the root systems could live many decades this way.

Overall this species should be planted because of its unique flavor profile.  Its tartness and different flavor are unique in the plum world.  No wonder it was carried in the pockets of so many people far beyond its historical range. This fruit was relished in Europe just like the peach was from China. There are even some old established hedgerows found in the U.K. brought by traveling mariners many years ago. 

Seeds are available after processing starting in October of 2022. A limited amount is available this year. Seeds were floated to remove blanks and stored properly to allow the embryo to continue growing during the summer and fall. 

To germinate the seeds: Mirabelle plums are often doubly dormant and require two winters to sprout fully. But some seeds will spout after the first dormancy and in some years the percentage can be quite high. Store the seed in a lightly moist media in the refrigerator  for 60-90 days at 33F to 38F. Some seeds will split after 60 days and can be plucked out and planted. Lightly cover the seeds with 1/4 inch soil or sand. Seedlings will grow slower than other plum species but will establish in very dry locations. The seedlings are quite twiggy at a young age and will branch even on 12 inch seedlings. It is best not to remove those until 4-5 years old.