Lowering the required chill hours, of a cherry tree, for instance, through (less chilly) almond rootstock? Feasible?

Using the next door's rugged avocado seedling to graft the tropical sourced one. Wise?

Best wild quince in the neighborhood usualy tops Mallings. True?



Actually, the cherry tree chill hours sparked this. The one I´m considering lies on a friends orchard and produced the precise amount of three cherries, this year. Should self-pollinate, been told. Some Almond trees just in front (traditionaly choosen here in warmer\lime solis for prunus) ... think I'll add some cherry toping and see how that goes...

You cannot graft a cherry scion onto an almond rootstock - not compatible:

http://www.crfg.org/chapters/golden_gate/Grafting%20HO%2005%20MG%2021.pdf

I suspect there is a cross pollination issue or chill hour issue with the cherry. If it's cross pollination, be sure you've got another variety that blooms at the same time. If not, you'll simply not get fruit, or very little. And, cherries do take a few years to increase their production. On my two low-chill cherries, Minnie Royal and Royal Lee, I had exactly 1 cherry the first year, a handful this season, and I am hopeful to have a decent crop this next spring. This is the typical pattern for our low-chill cherries, and for most cherries - it can take a bit. Some cherries are self-fruitful - I have a couple of self-fruitful varieties (Lapins and Craig's Crimson) which will set fruit just fine without a cross pollinator. Chill hours can affect fruit set, but it doesn't sound like you lack chill hours? Can't tell because you don't have your zone listed, but you're also talking about avocados, so chill hours could be a factor. With many stone fruits, you can fudge with chill hours, and grow varieties that are listed to require more chill hours than you may actually experience at your location. With the exception of cherries. They simply will not set fruit if they do not have their specific chill hours required for the cultivar.

We routinely graft more cold sensitive avocado varieties onto hardier seedling rootstocks here in S. California. I live in the heart of "Avocado Country", just south of Fallbrook.

Can't speak to Quince, I don't grow them.

Patty, I am not completely sure about the compatibility of grafting cherry onto almond, as I have never looked into it, nor done it. However that said, almonds can be bud grafted successfully on plum, peach, apricot, or cherry trees, because they are so closely related. Usually almond seedlings are selected for the root stocks, although peach seedlings are sometimes used in almond orchards where the trees are cultivated and irrigation is used. I only write this because if almonds can be successfully grafted upon cherries, why can't cherries be successfully grafted upon almonds?

I do know that both sweet and sour cherries are usually (normally) propagated by T-budding the wanted variety on a seedling of either the Mazzard or Mahaleb cherry. - Millet

I had posed this question actually, to some of the folks at Dave Wilson Nursery. Cherries seem to not do well on on other Prunus rootstocks. They are just a bit different than the other Prunus family members. You may get them to take, but they will not last. Sweet cherries don't even do well on sour cherry rootstock. Cherries are a little different than the rest of the Prunus family. I wish I knew why, Millet, I didn't get more of an explanation than that. I will see if I can find out more information about that. Interestingly, with all the interspecifics that the Zaiger familly have created, they just now have been able to release a cherry/plum interspecific. That tells me that cherries just aren't as compatible with the other Prunus cultivars.

Rootstock has no effect on chill unit requirement. Each bud on the scion collects its own chill units and doesn't even share that information up or down the stem to the next node.

True, Dr. Manners, but rootstocks in and of themselves, can provide additional hardiness to temperature. However, if the scion succumbs, well, it's moot at that point.

Rootstocks that are developed for dwarf trees and hard soils can cause a tree to go into dormancy earlier if not watered. I'm not sure if that affects the scion but it may help.


Get the minni royal and royal lee cherries. They are very, very low chill... like 150 hours.

Accumulated chill hours are temperatures above freezing, and below 60 degrees Fahrenheit. There are several models used, but I believe the most common model used for accumulated chill hours or "units" is the Utah model. Here's a nice article that describes accumulated chill hours, as well as symptoms that indicate not enough chill hours:

http://aggie-horticulture.tamu.edu/stonefruit/chillacc.html

I suspect what you're seeing, then are chill hour accumulation issues. What variety of cherries are you growing? If you are growing varieties than need over 500 ch, then you're going to struggle in zone 10a (which is also my zone). You'll want to see if you can find cherry cultivars developed for low chill areas. Not sure what you've got over there, but you might try to find Lapins or Craig's Crimson. Both are lower chill cherries and self-fertile varieties. Not as low as Minnie Royal and Royal Lee (cross pollinators for each other, and developed by Dave Wilson Nursery in California, so may not be available in Europe, but worth contacting Dave Wilson to see).

Mahaleb & Mazzard rootstocks are both used with sweet cherries here in the USA. They are standard rootstocks and are used based on your area's soil & growing conditions:

Mahaleb: drought tolerant, resists bacterial canker, and is tolerant of root lesion nematode and crown gall. It is very susceptible to Phytophthora , crown and root rot. This is supposed to be "somewhat dwarfing". Poo. Not here in S. California. But, good for our drier soils as long as you don't have an issue with Phytophthora, which I do, so I don't use it.

Mazzard: water tolerant, cold hardy, vigorous, and resists root knot nematodes. It is slower bearing than other cherry rootstocks. Very good for wet, heavy soils. Not an issue for me here in S. Calif.

I have my Minnie Royal and Royal Lee on Colt, which is supposed to be a semi-dwarfing precocious rootstock, but for me here in ideal growing conditions, I still end up with BIG trees (I needed to prune probably 6 feet out of my cherry trees that first season). However, Colt does well and is very precocious. I really prefer Krymsk 6 or Gisela 5 (or 12). Both Gisela and Krymsk are also very precocious, your trees will fruit sooner, and produce more fruit than on Mazzard or Mahaleb. However, I wonder about the longevity of the tree. Will have to see. For you, I would suggest Gisela 12 or Krymsk 5. Both are European sweet cherry rootstocks that do very well for dooryard trees.

Well, some cherries are not cross-pollination compatible (intersterile). Here is a nice excerpt from the University of Colorado that does a good job of identifying some of the varieties that are considered "universal pollinators" (which is why I have Lapins in my cherry selection):

Quote:

Some varieties, e.g. Bing, Lambert, Royal Ann/Napoleon, are also cross-unfruitful and cannot be depended upon to provide pollen for each other. Index, Lapins, Skeena, Sweetheart, WhiteGold, Sonata, Stella, Symphony, Sunburst, and BlackGold are self-fruitful (SF) sweet cherries that can serve as “universal” pollen sources for many self-unfruitful sweet cherry varieties (Stella does not work for Bing in some areas).

Here is the link to the page with the above quote:
http://www.ext.colostate.edu/pubs/garden/07002.html

Also, more info from University of Missouri:
http://extension.missouri.edu/p/G6001#Sweet

Brooks is self-sterile and does need a cross pollinator. It's a low chill cherry developed by University of California, and a nice cherry. It is one of the only cherries that is nearly free stone, kind of a nice trait. Ripens in Mid-May for us here in California. Cross pollinators for Brooks are Coral, Kansas Sweet, Tulare, Early Burlat, and Rainier. Rainier is a very nice cherry, by the way. It is a blush cherry, big, very sweet and it ripens right after Brooks, so you could get an extended cherry harvest. Not sure why Lapins is not included, and Lapins blooms in mid-spring as well, but perhaps it is a wee bit to early or to late, in comparison to Brooks. If you can pick up a Rainier, you would have two very nice cherries. And, the nice thing about Rainier is the fact that it's a blush cherry, and the birds often leave it alone.

And, more information about possible cross pollinators (this list is awfully long, and not sure the bloom times with all varieties will coincide perfectly to get good cross pollination). This is a UK source, so I thought if you didn't have any of the above varieties available, one on this site might work for you:
http://www.orangepippintrees.com/pollinationchecker.aspx?v=1439