Question:
- Have you done this for your home backyard cherry? Is it necessary?
Yes, I've done it. NO, it's not necessary imo.

- If I can not find ultra low biuret urea, is MG general purpose a reasonable alternative? it also contains certain micronutrients. If not, can you please recommend a safe product?
Miracle Gro GP would be a suitable alternative. If your set on doing it follow MSU's guidelines for nitrogen % and adjust your mix rate accordingly. The high N lawn version would likely provide a better value, but you'd have to dilute to the appropriate N%.

- What would be the formula rate for foliar application? (professional grower seems use urea 2%
Follow the label and adjust accordingly. In my opinion (that's all this is) 2% isn't worth doing, you will see little to no benefit from this. Perhaps they mean 2% of pure urea N which is something like 46-0-0, so you'd be spraying a +/- 1% N dilution?

I wasn't aware commercial growers applied fall foliar nitrogen. Everything I've ever read wanted nitrogen cut off well before winter to prevent trees from staying vegetative. This is to allow the tree to naturally harden off and go dormant. Not observing this or over-doing it could result in winter die-back. I've done this, but I think I way over-did it.
This is just mho, and I'm certainly no expert.
Personally, I'd skip this and early spring apply broadcast balanced fertilizer or an organic equivalent at the recommended rate. I'm not an expert though so I'll follow the thread and let the experts school both of us.

The risk of fall N application generating dangerous vegetative growth is not born out by research- sometime past mid-summer trees fail to respond this way and only store the N for the following season.

The article you linked was very interesting to me as the common practice is to apply foliar N. in the spring for apples. I've always simply done a broadcast application to the soil around mid-Sept with some N and a lot of K to get N to the spur leaves early. I don't see how a foliar application would improve on this since the K soil application is already called for and the trees will pick up the N fine from the soil.

The article is about stressed cherry trees, but for apples getting extra N to the spur leaves is a regular practice of commercial growers pretty much no matter the condition of the trees.

Of course this probably isn't needed for your tree, unless it has some disease issue- we have been gifted with an exceptionally good growing season in the NY region. I've never gotten better growth from trees here. Do you think your tree is under stress?

Thank you all for the invaluable sharing. I really learn a lot from you.

I am new to this. The tree I have probably not under stress, but it did plant late (end of may) and had powdery mildew since end of july, PM is under control with bayer's biofungicide and potassium bicarbonate.

back to my naive thinking,
tree in a pot "should" have limited root capacities to uptake N (and other nutrients). I am wondering if I can use fall foliar application as regular routine every year to help potted cherry grow / fruit better in "next" spring.

Also attached another link I think is related (for nursery plant)
http://www.ars.usda.gov/SP2UserFiles/person/4947/PDFs/2007/2007BiFoliarUreaNMPRO.pdf

Thanks again

Alex

Alex:

It most certainly isn't necessary. I never used foliar N on any of my potted cherries and hit 25-34+ brix.

Commercially yield, size, and appearance are all that matter for sweet cherry. Little incentive to maximize taste.

In a pot you will need to apply fertilizer regularly but none needs to be foliar.

Here are some pictures of my potted sweet cherries.

Pot and tree size:

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Rainier cherries from tree above;

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More varieties:

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This post was edited by fruitnut on Mon, Aug 25, 14 at 14:31

fruitnut,

Thanks for sharing. Your photo make newbies like me to think it is easy. :-)

- What is size of pot you used for the rainier?
- How often do you need to "repot" your cherries?
- How do you resolve the pollination issue when your trees are in a greenhouse?

Alex

Alex:

That's a 15 gallon pot and on Gisela 5 rootstock. It never was repotted and fruited about 4-5 yrs starting yr three. I gave it to a friend who has a nursery this summer after harvest. She sold it for $100 and gave me half, amazing. I would have sold it for $20.

Mostly I hand pollinated but also used bumblebees. Rainier was one of my better varieties for bloom and setting but not for eating. I prefer Selah, Sonata, Sandra Rose, Skeena, and Van, all dark cherries.