I am back hoping you can help me learn from my failures! I had a very healthy Romeo cherry bush in a pot last fall. I kept it outside all winter (zone 5), repotted including some ACE hardware bagged compost/manure. It bloomed and started to leaf out a bit this spring, and then turned brown and faded away. I dug out the roots (see photo) and it seemed like the tips were dead. I thought maybe 1) the winter freeze killed it (though they are from Saskatchewan!) or 2) I introduced some grubs - didnt find any - or nematodes or 3) no idea…Any ideas would be appreciated. Thanks! Derek
That has the earmarks of winter freeze injury. The top is certainly hardy enough. But even in Canada where it was bred soil temperatures would not normally go below zero. Soil that cold only happens in sandy dry soil with no snow cover. On rare occasions in eastern WA state orchards there is winter root injury at sub zero air temperatures. Dry sandy soil and no snow fits the usual case. In a pot in Z5 the roots could get pretty cold.
Was the pot buried or heavily mulched over the winter? Potted plants need extra protection over the winter. I always bury my potted stuff in big piles of mulched leaves or wood chips.
Thank you both for your replies. It was not mulched. I just left it on the patio (BTW the horseradish I did the same with came back strong.) I dont have a place to bury anything in the winter. I can bring my pots into the garage - which I do for my fig. I guess I should plan on doing the same for some apples I have in pots.
Since I want them to go dormant and get enough chill hours, what is the lower temperature cut off I should move them at? For example, can I let them go into the twenties for a while in November and then move them in before the sub zero Jan/Feb temps?
You don’t have to bury them in the ground. Just pile a thick mound of mulched leaves all around and over the pot. In the spring, pull back the leaves and spread them around your garden or flower beds. Make it look like a big, tree-volcano and it should offer enough root protection for the tree to survive the winter.
Common problem with container plants is that they warm up faster than the ground normally would and they break dormancy too early. If they start growing and then you get some very cold/freezing weather again, it will kill them. They should be kept in their storage location, preferably in the shade, under a tree or on the north side of a fence, until plants in the ground start to grow, or until they start to get leaves in that location, then they can be moved out into the sun…
not sure if you are still following this or looking for Romeo, but Home Depot here (Mi) has good sized plants here for $39.00 in about 5 gal pots.
just a thought…
Pots get colder than the ground does as well, so it’s possible the roots simply got too cold.