J.

Why is the plant in a container? Do you cut the plant back and bring it inside for the winter. Forgive me if I am mentioning the obvious but most blackberries fruit on two year old canes. The plant looks healthier than mine and I easily picked 10 gallons of fruit from each plant this year. I throw a bit of 13-13-13 under the plant each spring and this time of year right after I cut out the old canes.

Al

Hello Al! Thanks for you response!

My primary reason for going with a container was due to my location here in NC, where we have alot of clay. If I went with a container, I could put the plant into some good organic potting soil. The other reason was a watering method that I am working on, and wanted to test it out on something other than vegetables, and this seemed like a good test. So far, so good. I went back and found that I planted the blackberry in the container in June 2005, so it is 2 years old, not 3 as I first thought. I think it spent one year in it original 9" container.

I don't think I have gotten but a gallon of berries off this plant; again much more than I have gotten previously. Do blackberries blossom and fruit more than once, or is one time all you get?

Thanks again for the response!

J.James

Here is a photo of when it was first put in the container:

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By metalfillboy, shot with Canon PowerShot A400 at 2007-07-08

jethro:

You will multiply your production many times if you take that Triple Crown out of the container and get it into the ground, clay or no clay. Many of us start with clay, but a few years of heavy mulching changes it dramatically. Meanwhile, the TC plants will not rebel at clay at all. These canes have very extensive root systems that cannot be contained without sacrificing productivity of the plant, although you have certainly managed to keep yours healthy with your regular watering and fertilization.

I have my TC plants on a strong trellis, and allow them to grow vertically about 7 feet or so, then pinch or prune them off. The following season -- the fruiting season -- they will grow in vigorous laterals that I tie to the wires, allowing them to go 4 feet or so laterally if there is room on the trellis. That is where the bulk of the fruiting occurs, not on the main canes.

Getting the canes in the ground will also increase the size of your berries, as well as their sweetness.

Don Yellman, Great Falls, VA

Hello Don! Thanks for you suggestions!

While I may put this bush in the ground someday, I think for now I want to see how this bush is going to do over the longer term in a container. I understand that the root system can be vigorous, but I think that if you give a plant all the food and water it needs, it should do just fine. I do NOT pretend to be a biologist (engineer, actually), but I have had much success in growing vegetables in 18 gallon containers for the last 4 years, with this season being year 5 and things are looking really good so far. So what I did was to apply the same watering and fertilizer method to a perennial and see how it worked out.

And so far, I seem to have the watering and fertilizer working, but I think I need some help understand the canes and how/when to prune them. Below is a close up photo of some new growth from this year. The one I have labeled "primocane" is a cane coming out of the crown and is now about 8 to 9 feet long. The two that I labeled "lateral" are two canes that have come out of the side of the primocane.

Have I labeled these canes correctly?

If I have, should I go ahead and prune the end of the primocane, to allow more laterals to from?

Is it off these laterals that during the second year that the fruit will form?

One last question: I have some new flowers forming and new fruit setting. At what point do I cut the floricanes, so that the plant can focus on growing new canes for next year?

Again, thanks for your thoughts and suggestions, and to you, or anyone else, who can help me with pruning questions. I have included a link to a PDF put out by NC State on growing blackberries in NC. This is where I have gotten most of my information on growing blackberries.

J.James

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By metalfillboy at 2007-07-09

Here is a link that might be useful: Growing Blackberries in NC

J

New canes arise from the original root system and the old canes die back to the ground. I believe that the pot will confine the spread of your root system.

These plants are very agressive. Mine are 3-4 years old and new canes are coming out of the ground as much as 5 ft from the original root stock

If you want to experiment and learn you are doing the right thing but do not expect to maximize fruit production at this point.

yes, I think you have identified the canes properly but I would expect to see both one and two year old canes on the plant this time of year

Good luck, keep us posted about what you find out.

Al

Hello again Al!

Thanks for confirming the name of the canes. I think I will go ahead and clip the end of the long primocane and see if more laterals pop up. There are several other primocanes, as well as laterals, on this plant; you just can't see them in the photo. The foliage that you see below the canes pointed out are second year floricanes. I will keep an eye on them, and if they don't look like they are going to fruit any more, I will cut them back.

I know that both you and Don have concerns about the root system being confined, but I think I will be ok. I mostly base this on my experience in growing tomatoes in containers. I usually put two tomatoes plants into a single 18 gallon tote that has two 40 lbs bags of potting soil. Tomatoes also have very aggressive root systems and you would think confining them in a container would limit production. My 4 years of experience in growing in containers has shown this to be not true. Take a look at earthbox.com. Their system is based on a smaller container than mine and they have monster production on their tomatoes plants, and many on the vegetable and container forums here will also verify this. I can also verify this; I owned 3 of them at one time, but now use a design of my own.

The caveat to all this is that the black berry is a perennial, not a annual, like vegetables. I may find out in the next year or two that the plant's production will start to decline due to this root confinement. Who knows, but so far, the plant is healthy, happy, and has produced a bunch of berries. Now, I am trying to figure out how to prune them to possibly increase production, which both you and Don have helped out on.

Again, thanks for your input and advice. I will try and keep this link updated in the future when there are changes to the plant.

J.James

Jethroe:

Nobody is trying to talk you out of growing in containers if you prefer to do it that way. But if you want to apply the scientific method, split out one plant and put it in the ground, then compare the vigor and production of the two systems side-by-side.

Plants in the ground will also propagate themselves by tiprooting and underground spreading, which surely helps increase overall production, but is more problematic with container grown plants.

Don Yellman, Great Falls, VA

Hello Don!

I never took your's or Al's suggestions as a way of talking me out of growing in containers. :o) What you have done is to point out to me the limitations of growing in containers when it comes to a plant like blackberries.

But growing in a container does help solve the "problem" of the plant getting out of control. If I were going to put the plant in the ground where it is, it is only 2 or 3 feet from my neighbors fence. While I have really enjoyed my blackberry bush, I am not sure what my neighbor would say about a new blackberry bush growing in her side yard that has propagated under the fence. As aggressive as these plants can be, it might not be a bad idea to take a small hit on fruit production to keep the plant from getting out of hand, both in my yard and my neighbors yard.

What I might try next year (or may still have time to do it this year) is to try and tip root one of the canes into another container, to see if I can propagate another plant. I assume that this (and roots spreading underground) is the only way to propagate a Triple Crown? I think I read here that the seeds from a TC will not germinate. Have you ever tried this??

Again, thanks for your information and suggestions.

J.James

Jethro:

Triple Crown should tiproot readily into another container. I wouldn't say it is impossible to grow TC from seed, because I really don't know, but it certainly seems impractical. If I fail to prune and pin up my TC canes in a timely manner, they tiproot all over the place. You are right that they are vigorous growers.

Don Yellman, Great Falls, VA

Here is an updated picture of the TC.

I have pruned off all the floricanes, leaving just the primocanes and laterals. I have 4 primocanes, 8 laterals, and looks like a few more are forming. I am also attempting to tip-root one of the really long laterals (about 5' long). Will let you all know how this works out.

Several of the laterals have gotten about 3' long (actually, the two pointed out in the photo above). From what I have read here, I should tip them around 18" to 24". Is this correct?

Thanks for any feedback!

J.James

P.S. The 2x4 is used to keep the bird netting off the plant. Guess I can take it down now that the fruiting is all gone.

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By metalfillboy, shot with Canon PowerShot A400 at 2007-07-18

Jethro:

I let the laterals go 3-4 feet. They produce along the entire length. Doesn't seem to strain them. Maybe they could go even farther, so long as they are kept from drooping down to the ground. But in my planting, they meet laterals coming from the other direction from the adjoining plants.

Don Yellman, Great Falls, VA