Root pruning in 5 gallon sips?

[don_sanders]

Anyone know if fig trees grown in 5 gallon sips should be root pruned every year?

I was hoping that they would be fine another year but they seemed to have grown so fast that I'm thinking they will need pruned. Roots are growing into the water reservoirs of the bottom buckets.

Maybe cut 2" off all around (sides and bottom) once they go dormant? Think that will be enough? I'm thinking I might be able to get away without pruning the tops of the ones that I've trained to grow bushy?

Here's a pic of what I have growing. The one on the left is about 7.5' tall for perspective. I'll be pruning that one and some of the other ones down pretty heavily to train them to.

[jmaler]

I can't answer your question about root pruning, but I bet your wife croaks when that first cold snap sneaks up on you and you drag all those beautiful fig trees inside that patio door. LOL

[don_sanders]

Hehe, yeah. She isn't on board with my obsession yet.

[AscPete]

Yes, along with the seasonal branch pruning 2 inches above the reservoir platform and 1 inch off the sides has worked to maintain continuous growth in 5 gallon SIPs each season, . Good Luck.

[drivewayfarmer]

I let my 5 gallon SIPS go without root pruning for at least 2 years sometimes 3.
Growth has been very good.
I'm sure root pruning every year is fine as well , but I couldn't face root pruning that many every year , although pruning the 5 gallon SIPS is easy compared to my 25 gallon SIPS.
The plants in your photo look great.

[don_sanders]

Hmm, so every year or two. Maybe I'll have to take a look at the roots of some of the larger ones once they go dormant.

Maybe I'll experiment with letting one of the larger ones go without root pruning.

If I can get away with every other year, that would be nice.

[eboone]

When do the experts advise doing that root pruning for container figs? Any time after dormancy? Just after dormancy? In the spring right before they bud out?

[AscPete]

I'm no expert... but IMO root pruning can be done anytime after the tree has gone dormant or before spring bud break. My observation has been that roots will start to grow at least 1 month before bud break in the spring, so the Root Pruning should be completed before that time. Bare Rooting should only be done in the spring before bud break to reduce the chances of root rot (dormant roots in wet potting mix).

[eboone]

Do you have a recommendation for when to do the top pruning, if you are also doing root pruning? Do you think both could be done anytime thru the dormant period? Simultaneously?

[AscPete]

I prune in winter, the pruning cut leaves 1-2 nodes extra for die back, they're sealed with pruning sealer to prevent desiccation while dormant in storage and the final pruning cut is done in spring after the desired buds and branches have been established. The cuttings can be stored in the crisper (a better temperature controlled winter storage) for rooting later in winter or spring. Yes, I usually do the root and branch pruning at the same time. BTW, with a little extra care root/branch pruning and even bare rooting can be done at any time of the year, but it usually retards fig development.

[Bijan]

Ed,

As I mentioned, I prefer not to do both in the same year. I know this counters the conventional wisdom of pruning the top to match what is taken off the roots. Here is some information regarding auxin and root growth.

From a Colorado State University / Master Gardner publication:

Auxins produced in the terminal buds suppress the growth of side buds and stimulate root growth. They also affect cell elongation (tropism), apical dominance, and fruit drop or retention.

The last sentence makes me wonder if the reason we hear so much about fruit drop isn't due to pinching.

Here is the abstract from a paper (linked below) titled "Ethylene Regulates Root Growth through Effects on Auxin Biosynthesis and Transport-Dependent Auxin Distribution":

In plants, each developmental process integrates a network of signaling events that are regulated by different phytohormones, and interactions among hormonal pathways are essential to modulate their effect. Continuous growth of roots results from the postembryonic activity of cells within the root meristem that is controlled by the coordinated action of several phytohormones, including auxin and ethylene. Although their interaction has been studied intensively, the molecular and cellular mechanisms underlying this interplay are unknown. We show that the effect of ethylene on root growth is largely mediated by the regulation of the auxin biosynthesis and transport-dependent local auxin distribution. Ethylene stimulates auxin biosynthesis and basipetal auxin transport toward the elongation zone, where it activates a local auxin response leading to inhibition of cell elongation. Consistently, in mutants affected in auxin perception or basipetal auxin transport, ethylene cannot activate the auxin response nor regulate the root growth. In addition, ethylene modulates the transcription of several components of the auxin transport machinery. Thus, ethylene achieves a local activation of the auxin signaling pathway and regulates root growth by both stimulating the auxin biosynthesis and by modulating the auxin transport machinery.

I am admittedly not so scientifically savy as many people are. So please just don't take my word for it. It seems to as though the argument is that pruning the terminal bud (were auxin production occurs) will slow down root growth (recovery). My experience this year where most of my trees had significant cold damage to the top before I root pruned them mirrors these findings. The amount of top growth this year did not match my expectations.

The link function doesn't seem to be working.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1955700/

[Bijan]

I bare-root and root prune. This year, most of what I was transplanting went from 2 gallon RootPouches to #5 Airpots. I removed about 50-75% of the rootmass.

http://www.ourfigs.com/forum/figs-home/22203-bare-rooting-repotting-a-fig-tree-video

[AscPete]

Thanks for the reply...
I suspect that your reduced canopy growth was due to the large reduction in root mass.

[Bijan]

From my favorite "scientific" source, Wikipedia:

Ethylene is produced from essentially all parts of higher plants, including leaves, stems, roots, flowers, fruits, tubers, and seeds. Ethylene production is regulated by a variety of developmental and environmental factors. During the life of the plant, ethylene production is induced during certain stages of growth such as germination, ripening of fruits, abscission of leaves, and senescence of flowers. Ethylene production can also be induced by a variety of external aspects such as mechanical wounding, environmental stresses, and certain chemicals including auxin and other regulators.[27] The pathway for ethylene biosynthesis is named the Yang cycle after the scientist Shang Fa Yang who made key contributions to elucidating this pathway.

[AscPete]

Attached are photos of established fig trees in 5 gallon buckets, from bare rooting and root pruning through fig production this year. The last photo is of the tree with a few stagnant figs that could ripen if the trees were placed in a greenhouse.