Pruning Roots before Transplanting Experiment -- To prune, or not to prune?

It's late fall, which for many of us, especially in the hotter climates, is the best time of the year for transplanting. Which means I'm usually ordering way to many plants and rushing to get them in the ground before it gets too cold outside. I've always wanted to experiment with pruning the roots of my plants to see if it would help the plants get the best start, or if planting them with the roots fully intact is best.

For my experiment, I ordered six Arapaho blackberry plants and randomly selected 3 to prune and 3 not to prune. The roots were washed and untangled for each one. I am planting them beside each other, so the soil and location should be the same.



I've also done this with blueberries and fruit trees this year, but for scientific purposes, they were not done as precisely as these blackberries were. However it still should be interesting to see the results with them and if they are different.

The benefits for each one that I could think of after planting them and considering future benefits are...

Not Pruned...

  1) Plant has more roots to support it through transplant shock
  2) Plant is not being injured, and won't have to spend energy healing

Pruned...

  1) Easier to plant- the roots are more rigid and keep their shape while backfilling the hole, and a smaller hole can be used due to less roots
  2) Encouraging roots to branch out more as a result of the pruning

Which way do you think will work best? Do you transplant your plants a certain way or had results using other beneficial techniques? I'll be posting updates along the way and the results to come! Happy planting!

 

I would prune tops rather than roots. Roots are almost everything for plant survival and if there is a big healthy root system for a small top it will soon grow a big top. If the top is too big for the roots to keep fed and watered it's going to die.

Great point Mary.

I'm going to add 6 more blackberry plants of a similar variety, 3 with pruned tops and unpruned roots and 3 with pruned tops and pruned roots to widen the experiment to include for this.

I'm just remembering that one of my favorite fruit plant sellers appears to prune both the top of the plant and the roots, and those plants usually have a burst of growth in the spring and are very healthy.

I was thinking that by planting in the fall, the pruned roots will have time to adjust and maybe even grow a little before spring to be ready for the new top growth in the spring, and the tops of the plants are only 6 to 9 inches so there hopefully shouldn't be a whole lot of top growth to support. We'll find out soon I guess if they all die!

Wonderful observation, keep them coming!

Plants will self-prune their roots if the root-to-shoot ratio is out of balance.  Basically, they'll shut down nutrition to long extended roots that are not necessary.  The inverse it not true: plants do not generally self-prune branches that are too long.

I wouldn't take off any root mass unless the roots are girdled or bound.

Good point Marco.

I was actually thinking that by planting a large mass of roots, unless a person is really careful when planting which I am not , all the roots may be clumped together from the weight of the first initial shovelful of dirt going in the hole, causing all the roots to be right together resulting in minimal nutrient absorbsion and possible severe root girdling in the future.

Great ideas so far keep them coming!

Hi Steve,

I prune my roots to lay evenly on the bottom mound before filling the hole.  I also prune any broken roots.  Once the tree or bush is planted I prune the top.  I want my plants to struggle a little bit to survive.  With no proof, I feel like a little pruning of the roots and the top makes for a healthier plant.  

For stuff that has roots growing close to the surface, I only prune damaged roots or that crazy wild root that extends way beyond the root ball.

Let us know how it works for you.

Cheers, Scott

Great information, thanks Scott.

Yeah, I think I'm leaning the same way, that a little pruning of each will make the healthiest plant and that a smaller surface area will help the plant adjust quicker to its new spot.

It's always hard for me to prune a plant, especially the top part of a fruit tree, but I'm thinking it should end up greatly helping the new plant get the best start.

Great info, thanks again Scott!

Steve Thorn wrote:Great information, thanks Scott.

Yeah, I think I'm leaning the same way, that a little pruning of each will make the healthiest plant and that a smaller surface area will help the plant adjust quicker to its new spot.

It's always hard for me to prune a plant, especially the top part of a fruit tree, but I'm thinking it should end up greatly helping the new plant get the best start.

Great info, thanks again Scott!

I think that in most cases if you have an amount of root mass to match your upper structure you should be good to go.

Yeah, I'm thinking that's also going to be a very important factor Scott.

I guess my "hypothesis" will be that a slight pruning of both the roots and plant will help it adjust best to transplant shock, and that a balanced pruning of each one could help ensure a well founded support for the upcoming growing season.

Excited to see what will happen!

Some good information has been given by several people here.

Cane type woody plants (black berry, raspberry) are a bit different than true trunk type, deciduous trees when it comes to planting bare root.
Canes will benefit from a top prune back with the roots left as long as possible, these plants usually bear fruit on new growth instead of second year growth.
When spring comes new main canes will come from the crown and the more root support that is already there, the more main canes will sprout from the crown.  

Blueberries and all other fruit trees (those with a trunk) can do very well if the roots are trimmed about an inch back into the root ball when being planted and the tops also need to be pruned back when being planted.
This allows for new root growth in the spring which also brings out new branch growth (thicker top branching).

Redhawk

Just yesterday, I pulled a black genoa fig growing in a small pot and transferred into a root pouch. The roots were all tangled in spiral and I pulled them apart removing some thick ones before transplanting. I am hoping the roots will recover and the tree starts growing again.

I think with every pruned root, the fertilizing is important for the first couple of weeks. A good liquid fertilizer would help a lot with the recovery.

Gurkan Yeniceri wrote:Just yesterday, I pulled a black genoa fig growing in a small pot and transferred into a root pouch.

That's neat, I had never heard of the term root pouch before, I think they call them grow bags around where I live. I had seen people online pruning plants in existing pots and also before transplanting to new pots, which partly inspired this experiment!

Gurkan Yeniceri wrote: The roots were all tangled in spiral and I pulled them apart removing some thick ones before transplanting. I am hoping the roots will recover and the tree starts growing again.

I had to do the same for mine that came in pots, one of the many reasons I prefer bare root plants. It took me forever to untangle some of them.

Gurkan Yeniceri wrote: I think with every pruned root, the fertilizing is important for the first couple of weeks. A good liquid fertilizer would help a lot with the recovery.

I'm trying to minimize my inputs, to make it as cheap and simple as possible. My soil they will be planted in is already pretty fertile and we get lots of rain this time of year, so they should get a natural "compost tea" kind of boost during the dormant season.