This extremely hardy yellow sweet plum has been known to withstand temperatures of -40 F or more. From Northern China and other locations, this is one of the species used to create 'Shiro' and other Asian plums that are so incredibly sweet and delicious. Not much is known about the origins of my plants but thanks to a customer who let me grow out several thousand seedlings of one plant he had in his orchard, I was able to select several very nice black knot resistant plants that produced amazing yields of sweet small yellow plums. Despite early flowering, the plants tend to set fruit quickly and are rarely damaged by late frosts. Fragrant flowers attract a huge variety of pollinators in spring.
My seed selections are grown from the most vigorous parent trees reaching 30 ft. tall with straight upright trunks. The Ecos selections are highly resistant to black knot but more works needs to be done to improve on this. Two years ago I made some small additional selections that I feel will show more resistance to this disease which is really impossible to control if you are going to a no or low spray system. These plantings are not fruiting yet or just starting to.
Initially I tilled under many thousands of seedlings to find a few that are almost immune to this rather devastating disease which is quite common in North America. Black knot survives on many commercial shade tree selections of Canadian cherry ornamental plums you see used in my area. The cities of Portage and Kalamazoo, Michigan seem to love them. It is also found to a limited extent on chokecherry in the wild but it is very rare here that it occurs. In a somewhat ironic genetic twist, the trees with only slight black knot disease also are the most productive so the disease must play a role to some extent in the plants success of reproduction.
There might be some clonal selections done on this for yields and better disease control. For me there is little variation on seed grown plants of this selection but black knot resistance can easily be selected further as well as overall yields. Grow outs with the seeds I offer could both improve the seed source in that respect and make it possible to find a new type of plum which is similar to apricot yet not so early in flowering. On another note: the wood is amazing in its hardness with its well marked rings and coloration. So if the orchard gets cut down or comes to the end of its life, the wood should be saved and used for musical instruments like recorders or other uses where a hard fruit wood is desired.
To germinate the seeds, plant outdoors in the fall 1/2 inch deep in a garden type soil with good water drainage. Seeds will almost all germinate in one season (one dormancy) although a few seeds may sprout in the second year.
To do the indoor method, store your seeds in the refrigerator from 33-38 F for 60-120 days in a ziplock bag with lightly damp Canadian peat moss. Seeds will germinate in roughly 60 days as the seeds will start to crack open slowly. This is the time to pluck them out and plant them in a pot. Make sure the soil mix is light and well drained. Ussuri plum seeds rot easily in high organic soils. Some seeds will need an additional warm and cold period to sprout if some do not sprout the first year. Plants can grow to 3 ft. in one year from seed. Quite vigorous from seed.
Will produce fruit in 3-5 years from seedling.
|Genus & Species||Prunus salicina var. mandshurica|
|Hardiness||minus 40 F|
|Height (ft)||30-40 One of the tallest plum species at my farm.|
|Pollination Requirements||Self fertile. Does not cross with other plums readily as the flowering is so early. Flowers and sets fruit quickly. Having two plants may aid in increasing yields of a seedling planting.|
|Climate||Zones 3-7. Heat and cold tolerant to a wide degree of adaptability.|
|Ease of Cultivation||One of the easiest species plums to grow from seed which always come true to its yellow color. Its fast growth from seed and heavy fruit set make it ideal. Its early flowering is a problem for some and some insect damage may require a bit of neem to keep it in check otherwise a fairly care free plum species. See black knot in description details.|