Cherry Interstem Grafting Questions

Earlier this year during bare-root season, I planted 4 sweet cherries together in a high-density planting situation. All 4 trees are planted together in a 4’ x 4’ raised bed with about 24" between the trunks. The varieties are Minnie Royal, Royal Lee, Lapins, and Craig’s Crimson. They are all on Maxma 14 rootstock.

I am in USDA zone 10a, Sunset zone 17, so I tried to get the lowest-chill sweet cherries I could find. I wanted Royal Crimson instead of the Lapins or Craig’s Crimson, but it wasn’t available on Maxma 14. Due to the high-density planting situation, I decided it was more important the trees all be on the same rootstock. That may have been a mistake.

It appears after watching the trees leaf out that I may have to replace the Craig’s Crimson because the chill hour requirement is too high. Obviously, due to the high density planting, I can’t just dig it out and plant another tree there as the roots of the other trees would be damaged. So I am thinking about topworking the Craig’s Crimson with a different variety. My question is, does the CH requirement of the variety that is being used as an interstem (the Craig’s Crimson) have any effect on the variety that is grafted to it (would probably be Royal Crimson or Stella)? Would it work to do this? What would be the best type of graft to use? I have only grafted apples, and have no experience grafting cherries.

Thank you in advance for your help.


Do you know of anyone else in your area that has cherries fruiting? I would not put a lot of stock in chilling requirements. If other cherries are fruiting there, that one probably will too. Even later if it doesn’t you can graft it and it will be easier because it has established roots.


The short answer is, no, I don’t. Most people here don’t even bother to grow plants, much less temperate fruit trees, because of the cost of water. The ones who do aren’t brave enough to try planting something that might not bear fruit. If they even try, they typically go for the tried-and-true low chill varieties.

I am the neighborhood zone-pusher, lol. I had to practically sign a waiver to get the local nursery to order Jacaranda trees (a beautiful Brazilian flowering species) for me because they said they would never grow here. When I insisted I wanted to try, they stared me down and said “Have you seen any in town?” I finally told them to just order them anyway; I was willing to take the risk. All 3 of them are growing beautifully, BTW, and 2 of them bloomed this year.

So if I went by what other people here grow, I wouldn’t be growing anything at all. :smirk:

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This is what I heard from Andy Mariani and other stone fruit growers around Bay Area and not my personal experience. So, take it with a grain of salt. Cherries are notorious for sticking to their chill hours and refuse to even bloom if that’s not met. That doesn’t say the number marked on the tag is accurate but they are not forgiving. Other stone fruits like nectarines and plums will bloom and set fruit miserly without required chill being met but cherries won’t likely set anything. So, I’d graft another low chill variety instead of Craig’s Crimson as I heard its finicky even with good conditions. Chill hours should only affect the blooms and not the growth, so I wouldn’t worry about interstem. I used cleft graft with success with cherries in my limited experience.

Your Jacaranda trees sound great. Post some pics of their bloom!

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@californicus That is what I was hoping to hear, that the interstem wouldn’t be a problem. At worst, I could just graft Minnie Royal and Royal Lee onto the Craig’s Crimson and Lapins, as both of those trees seem to be doing quite well. The Minnie Royal even bloomed.

Unfortunately, the jacarandas just finished blooming and I didn’t take any pics, so I won’t be able to post any until next year.

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Chill requirements are mostly relevant for buds (vegetative buds and especially flower buds), so I do not expect an interstem to have any effect.

Use any graft type you feel comfortable with – cherries are pretty easy to graft. For well grown understock, bark grafts are easy and have a high success rate, but need to be protected against breakage by birds or wind.