Mulberry pruning to induce fruit doesn't seem to work

[Yook]

Hi all. I have three mulberry plants in the ground. Two worlds best that I started from cuttings and 1 dwarf everbearing.

I have heard that cutting these guys back hard in the winter and then after the first crop is done can help spur more fruiting. Unfortunately, my trees seem to only produce a handful of berries at each bud break after pruning, and then proceed to produce tons of vegetative growth, usually as single shoots without branching. I've kept the dwarf everbearing as a central leaderish shape, and the WB more as bushes.

I have experimented with fertilizing one of the worlds best and not the other(Osmocote slow release, 15-9-12 or something I believe) and didn't see much difference. The plants seem healthy.

Any clue why these mulberries aren't loading up with fruit all along the new branches like I see in so many photos? This occurs on both the WB and dwarf everbearing so I'm not sure what it could be. I'm not getting much fruit on either the first set or when I prune afterwards.

I appreciate any help. Also would like to say thanks for helping me get going with tree growing a few years back. We have been enjoying Brogdon avocados for the last 2 months. The first crop of lula avocados is on the way. Starfruit just set and loquats have been great as well. All thanks to your guidance.




The WB are the two bushes on the right of the island in the picture. Ignore the dying tomato.

[pineislander]

I put in 20 of the World's Best in 2020. I tipped constantly the first season but after fall let them grow long branches to be ready for fruiting in 2021. Even though my zone is 10B they went fairly dormant during winter and I did not cut them back. In spring that was when they made a good crop, as the weather warmed all the buds along the long dormant branches came to life and fruited very well. After that, I pruned back again and did get a brief second crop but what I noticed was far less fruit, more vegetative growth and the fruit didn't ripen as well, many fermented due to steady summer rains.

Perhaps your winter pruning removed branches with older wood which needed to lie dormant during winter to set them up for flowering in spring. This year, try leaving branches about as long as what you show in the pics, let them go dormant, and watch what happens.

Here was my spring crop on one year old plants:
https://www.youtube.com/watch?v=6a9L8jvyhqo

[achetadomestica]

Spring crop is always the best and highest production.
I notice a few of mine have some fruit now probably cause we
finally got some rain a few weeks back. I agree with Jay the summer
fruit is not as good on my trees either.

[palmcity]

Agree that fruit taste is so poor vs. spring fruit it is not worth trying to force the tree to fruit... But if you really want to see a few try pulling every single leaf off the mulberry tree instead of just prunning.

A few years back a landscaper said his client could not get fruit in the spring and asked me why. I asked him what did the tree look like and he said the guy fertilizes and waters it all year and it is really big but never sets fruit.

As was mentioned earlier, a dormant season is required Jan. Feb. in S. Fl. to get big bud swells and put out a big flush of leaves and fruit bloom in the spring. The guy watered all winter and it never lost it's green leaves as he got upset when they started yellowing... I told the landscaper to tell his clinet to stop the watering at least in Dec. and probably earlier in even Sept. as I never water mine unless a small tree that I think might die in the summer heat but as long as a green leaf is still on it I would refrain from watering even if 90% of the leaves drop off. During dry summer periods this has happened in the past and with almost all leaves dropping in July to early Aug with dryness & heat and then followed by a few cooler weaks of rain... Rusults in new leaf growth and a few blooms and a few fruit but not worth it to try to mimic this by picking off all the leaves.

Stop watering and fertilizing at least in Oct or earlier as I never do and the trees bloom fine in the spring.

[kh0110]

From my limited experience with mulberries, removing leaves is the only way I get my trees to set fruits again in abundance. I prune them heavily also to keep them short but only leaves removal would trigger abundant fruiting and I remove almost ALL the leaves leaving only about 10%.

This was my observation when I was experimenting with the way leaves are removed in order to feed silk worms.

[Kevin Jones]

I can't speak from first hand experience... but the variety "Worlds Best" appears to be the same... if not very similar to the Thai Dwarf Mulberry.
I have had excellent experiences with the Thai Dwarf Mulberry.
After the initial Spring fruit flush is over... I cut the trees back by 2/3s and hit them with Miracle Grow fertilizer.
They immediately start regrowing new branches that are covered with fruit as thickly and as tasty as the Spring fruit.
Plus... all of the pruned branches can be easily rooted to start new trees... one of the easiest to root.
This technique does not work with most of the other varieties of Mulberry I have tried it on... Pakistani, Shangri-La, Shatoot, etc.

Here's a few photos of September berries after an August pruning from a couple of years ago:







The plants were so full I had to toss netting over them to keep the birds away.

Kevin

[Yook]

Kevin, when you say your branches are loaded, are you meaning the new branches grow fruit along their entire length? The picture you sent seems to show only fruiting at the bud break for the new branches. I’m thinking you guys are right and that I need to keep more old wood. I see so many people saying to cut back super hard but the tree really doesn’t seem to like fruiting on new wood so there must be something I’m missing. These guys did go dormant last winter but I also cut them back way far to like 10 stems so I’ll just leave them be this year instead and see if they fruit better on these giant shoots.

[Kevin Jones]

It will only fruit on NEW wood after a hard pruning like I am suggesting.
Very rapid growth with lots of fruit.
I prune back EVERY branch to divert all growth energy into new branches.

Kevin

[sc4001992]

Yook, I agree with Kevin on how to trim the branches. But after looking at the photos of your mulberry tree/bush it looks to me that you branches are still too small to be having fruits. How long have you had the trees in-ground ?

If your plants are not from fruiting branches/scions of a mature mulberry that was fruiting then you trees may not be old enough to have any fruits. I'm sure your tree will start to have some fruits next year if it is at least 3 yrs old. I get fruits on my seedling plants (18" tall) which I graft scions from my fruiting trees and that's normal for my grafted plants. But the small plants can't hold much fruits until the branches grow out. Also if you don't have a mature tree to graft the scions then it may not fruit for a few years after you graft it. All of my new grafts I did this year (spring) of mulberries cuttings I got from Marta (Really Good Plants) have had fruits this summer and branches are already 2-5 ft long on my older trees.

If you know how to graft, and you want fruits for sure next season then send me a PM and buy some of my Thai Dwarf/World's Best mulberry cuttings I can sell you. All of my cuttings will be from fruiting branches so if your graft takes, you should have fruits by next summer. Here's a few photos of my 1 yr old grafted Thai Dwarf branches with fruits I had this year (from April-July). I had over 40 lbs of fruits on these grafts.









Comparing Thai Dwarf and World's Best fruits and leaves: [Thai Dwarf 2 on left, World's Best on right]

[socalbalcony]

Thai Dwarf should fruit on new wood after a prune of more than 40% of branch length

Pakistani should fruit on new buds after a leaf strip - though won't fruit as aggressively as spring, sometimes Pakistani will fruit again on its own in the fall in warmer regions but so far leaf strip is the only way I've been able to force it - people here in socal do get fall crops with no intervention though..

[K-Rimes]

I had a stunning fruit session on my white mulberry and I tipped all the branches and got a weak second fruit session but the fruit wasn't as good at all and most didn't ripen correctly.

At this stage I don't care much about the secondary fruiting and don't think about it, I just trim for aesthetic, airflow, and size control now and if I get more fruit that's cool.

[sc4001992]

Yes, I agree, my Thai Dwarf still gets a few ripe fruits now but I just trim back my branches that were weeping from all my fruits from summer (May).

[Timbogrow]

Works on my tree every time it gets cut it tries to fruit. I had pruned mine back to 6' without leaves. It was having some powdery mildew or something always making the leaves turn brown and fall off. Seems it's cured now. I have 4 cuttings in 3 gal pots fully rooted ready for free/trade if anyone local is interested. I don't want any more mulberry.