I have a 3x1 graft plum tree, Santa Rosa has 10-20 fruit per year. I bought this tree from Home Depot as bare root, maybe 4-5 years. Shiro is the most productive so far.
I give all my trees a fruit tree fertilizer stick, Vigoro 16-4-8. Frankly, I don’t have a clue what the numbers are but they seem to work.
@GiddyUp Ok, so far so good! My next query is about pruning. Homeowners out west with fruit trees and garden maintenance services often experience lack of production because the crews prune for appearance and unfortunately on plums often remove fruit spurs. The best guide available for western gardens is the pamphlet How to Prune Fruit Trees by R.S. Martin. Be sure to look at the section on “training of young trees” in addition to the couple of pages for Plum.
@Richard Ok so you think that fertilizer is OK? (I saw someone else saying lower N and higher P&K is better?). Regarding pruning, as it’s a still quite a young tree honestly I’ve not pruned it at all so that’s definitely not the issue. But thank you I will read the ‘how to’ link you shared!
2 Likes
I’ve got a Santa Rosa next to a Japanese plum (“Gold” from orange box store) and last year it had 5 blooms and produced 1 plum while the Gold had about the same and no plums. This year they both have tons of fruit, likely due to the cross pollination. If you can, get a pollinator for it, or graft another variety in, or even use a smaller potted plum you just plop next to it temporarily during bloom.
1 Like
@SoCalGardenNut Thanks for sharing and awesome happy it’s working for you! The numbers are telling you how much Nitrogen, Phosphorus and Potassium are in the fertilizer (N, P & K).
1 Like
Yes, be careful about frequent applications of compost – it adds more “N” each time. I add compost once to the soil mix, then never again. Instead I have masonry tree rings of significant radius. After planting a tree I put down about 1.5 inches of 1" diameter Sequoia bark (not dyed). Afterwards I never rake within the tree ring and let leaf fall accumulate.
2 Likes
In northern WisconsinI would think it was great to have any plums at all by third year. Things mature much more slowly here.
1 Like
Hi Sally
Welcome to the forum. You can get some very good advice here
While Santa Rosa plum is self fertile, you can significantly increase your fruit set by growing other Asian plums nearby so that cross pollination is possible. This is true of all types of fruit and particularly true for stonefruit. Another important point is to try to match blossom schedule by checking with other members nearby to pick varieties that blossom generally at the same time period.
Best of luck
Dennis
Kent wa
2 Likes
Thanks @DennisD yes I have heard even when self fertile another tree is good but the only other space in my yard is grass. I guess maybe I could put one in the lawn but don’t think my husband would like that plan! I was considering getting one and just leaving it in a pot but not sure how long they can stay in pots? Also this year my Santa Rosa literally on blossomed for about 1-2 weeks so I’m concerned it would be hard to get something to blossom at exactly the same time!
@Richard thank you so much you are being very helpful! Good to know re the compost. Why Sequoia bark specifically? And what do you mean you never ‘take’ within the tree ring? And can I assume you let the leaf fall accumulate to add more nutrients and to help keep the soil moist?
I’m also on the west coast in zone 10a, halfway between Los Angeles and San Francisco. I have had Santa Rosa plums in several places I have lived, mostly the weeping variety. My experience with them is that they fruit very young and so heavily you often have to thin the fruit. It almost makes me wonder if the graft died on your tree and you just have rootstock, or maybe it was mislabeled and is really a different variety that is not self-fertile?
Another possibility–this one is kind of a longshot, but it happened to a friend of mine–it could be the rootstock it is on is inappropriate for your area. My friend bought an apricot on St. Julien rootstock (which can also be used for plums). She has had the apricot for 10 years. It grows and blooms, but never sets fruit. The graft is a variety that usually does well in this area–it’s just the rootstock that is weird. The same variety on Citation is already fruiting in her yard, and she bought that one less than a year ago.
Santa Rosa is the Japanese plum that most people have around here, and it’s pretty much foolproof. I don’t spray mine, or really do anything to it other than prune and pick. The chickens in the back yard take care of fertilizing it, and it gets watered by the lawn sprinklers.
2 Likes
Typo, should have been “rake”.
Yes, the slowly decomposing sequoia bark + leaf fall mediates moisture evaporation from the soil – a serious problem in our environment.
Note also that my irrigation is by 4 shrub “streamer” heads mounted inside the tree ring perimeter. The goal is to completely soak the basin each time they come on – about 8 minutes with my local 50 psi water pressure. During the summer months this is once a week. I did not operate them at all this year until last weekend.
The “Sequoia Forest Products” brand bark is the best quality for cost I’ve found in our region. It comes in 2 cu.ft. bags. I’ve never seen it at big box stores, maybe at Green Thumb or Walter Anderson Nurseries. The commercial supplier “Nutrien Ag” definitely has it.
Chances are Sally, you could find someone near you who could help you learn how to graft on several likely varieties. Space is limited in most members’ property which is often the incentive to start grafting. You can check the member map to see who your neighbors are and inquire about their grafting skills, or just learn by doing it yourself as I did a few years ago. I have a local grafting partner and we share our good ideas and teach each other what we learn. You have that opportunity on this forum, so just start! You will discover many options you have yet to consider, the door is open to you! Good luck
Dennis
Kent, wa
1 Like
@GiddyUp …well after setting 100 tiny plums yr 1 … we got a pretty hard frost and all turned dark and shriveled and fell off 
The leaves looked sad for a week or so but they recovered and it is looking great today.
I planted it with a pollinator Shiro… but my new shiro only had 1 blossom and it bloomed a few days after Au rosa quit blooming.
So I am pretty sure that my 1 yr AU rosa plum self pollinated and set 100 plums… all by itself… i was impressed with that.
I grafted a scion of AU producer on my AU rosa… so next spring there will be 3 in the mix producing pollen.
You might consider grafting on to your Rosa next spring a couple of good pollinators… to help increase your fruit set.
Good luck !
2 Likes
Now maybe it’s because there are many backyard plums in western San Diego county, but I’ve never seen a Santa Rosa that needed a pollination partner.
I hope so Richard I am counting on them as pollinators for other Asians
Dennis
So I assume that the tree is otherwise growing well? Too well? (possibly too much N).
If so, you might want to spray MPK on it. About 1/2 teaspoon per gallon. Roughly 300 ppm if you have one of those meters. Maybe with a few drops of liquid detergent added for stickiness. I use Dr. Bronner’s ‘cause it’s organic. I did this every few weeks during growing season.
Monopotassiumphosphate is the active ingredient in Gatorade. It is highly soluble highly potent P and K. Reputed to help flowering. The dope growers use it a lot.
I thought it helped on my Mirabelle plum. No way to know for sure.
If you have lots of exuberant growth you want to cool it on the N and almost certainly the P (Phosphorus).
1 Like
A reasonable approach in your location but something I’d avoid on Prunus in the southwest.
Why the Southwest?
We primarily supply nutrients to the roots because evapotranspiration rates are high in our environment. Also, our environment is primarily alkaline due to water sources with pH around 8.1. An MPK solution in neutral, unbuffered water is about 10. Nonetheless, it is applied foliar by commercial growers of nuts (incl. Prunus almonds) later in the season along with Zinc chelate to improve crop quality and weight.