leggy potatoes plants were started too early in the hous

started my seed potatoes using Espoma potting soil and they have grown very large(picture attached) I am planting them outside in large containers but the weather is still not warm enough here in NJ. Some of the plants are over 12 inches. SInce I am planting them in containers and will need to hill them can I cut off some of the top parts of the stem without damaging the potatoe plant. If so, how much of the stem should I cut. WIll that prevent the plant from flowering? must the plant flower to produce the tubers. The root system  has become root bound because of being in small container. What can be done to loosen it so that the tubers can grow My main concern is  how to plant them in the containers because they are so tall and once I put down the 4 inches on soil under them it would leave not too much more depth for hilling. the containers are 16" deep and 18" wide. So once I put them in, I am left with 12" of room for hilling. Given the length of them now, I could only hill one time and leave about 4 inches of growth unhilled and all the new growth would just be unhilled. Hopefully, enough of the stem would be buried to allow new roots to develop and  the tubers to grow. THanks for your help.

Welcome Professor! So you started potatoes indoors? And they got leggy? I have grown potatoes both in the SFG, and the traditional row garden.

How are you intending to hill the potatoes in the containers? In a row garden, you just plant them and cover as they grow to keep the tubers under cover.

Potatoes do not need to flower to produce tubers. Some flower, some don't. I have never chopped my taters back though.

Chop one back and let the other go wild, see which does best! Science!

Keep notes....very important!

Scorpio Rising:  Thank you for your suggestions. I like the idea of experimentation. I would hill them up in the container by carefully placing the potting soil around each of the plants and leaving about 3 inches on growth uncovered. I am just concerned about the root bound problem.

Yes, the root bound thing is an issue. I grew my first Yukon gold potatoes last year in my SFG. They were abundant and did both flower and produce little tomato lookin seed thingies that I have never seen!

I got 4 or 5 lbs of taters from 2 seeders. Ace Hardware. .

This year? I rescued a sprout from the compost pile this week and stuck it in! Yes! Free potatoes! And a Swiss chard also, yellow.

I have never tried starting potatoes indoors.  I am curious why you did?

Depending on the type of potato it might not need a lot of hilling.  Most of the big tuber potatoes only make one set of tubers in the bottom 4" above the root mass.  You mostly then are hilling to keep developing tubers from greening and to keep them cool. 

My potatoes sometimes get frosted back to the ground in early June.  They can lose a good 6" of growth and bounce back with out problem.  But I would not cut them if possible.

I seem to remember that one issue people planting potatoes in containers have found is keeping the soil cool enough.  I think Sanderson resorted to reflective insulation wrapped around the pots. 

What kind of potatoes are you raising?

Turan:  Thank you for your reply. I am planting red potatoes in containers because my garden soil is very poor with lots of tree roots. I am using Espoma container soil, their earthworm castings and their biotone fertilizers.

Do you have any suggestions about the root bound issue I have because of the plants being in the small containers for so long. Is it o.k. to plant it like it is which is very compacted or should I try to loosen the roots by perhaps soaking them in water so that they are not so tight. In this state I just cant envision how the tubers can grow from these roots. Any suggestions would be appreciated.

Professorm,  Welcome to the Forum from California!    I have grown small red potatoes in 5 gallon buckets with success.  And, I have had failures.   I wrap my white food-grade 5-gallon buckets with aluminum foil to keep out the sun and to keep the soil from heating up in our hot summers.  Then, mulch the tops with chopped bedding straw.  How big are your containers?  If I physically had more room, I would have more SFG beds and plant them in those.  As it is, buckets are the next best thing I can do.  I also have sweet potatoes in storage containers.

I think now is planting time for tubers outside for you, it is for me and I am a couple zones colder.  So you have the option of doing some of both, started indoors transplants and some planting seed potatoes direct in your outdoor containers.  I have never transplanted a potato and do not know how adaptable they are to that.
The tubers do not grow from the root mass, they grow from the underground stems  above the roots but under the soil.  They can take a good deal of crowding, that is how Mel gets away with suggesting 4/sqf.  The tubers will be smaller though.

Careful with the fertilizers.  Potatoes respond to nitrogen with lots of top growth but few tubers. 

Fingerling potatoes respond strongly to hilling and will put a couple or so layers of tubers along their stems in tower systems.  I have not had much of that happen with regular potatoes, some with long season varieties.   Red potatoes will like a hilling to keep them cool and tubers from greening, but you do not need to think of more than once or so.

I hope that helps

Turan:  As you can see, I am a novice regarding potatoes. I am a bit confused now. When I looked at all the pictures of potatoes growing under the earth, it appeared to me that they were growing attached to the underground roots. So this is not true? If I understand your statement correctly "The tubers do not grow from the root mass, they grow from the underground stems  above the roots but under the soil." that to me means that the tubers are actually growing from the stems that are hilled and thus underground but are on top of the orginal root mass. So the tubers are growing out of the stems and not from roots. Please correct me if I am still not understanding. So if that is true, then I should not be concerned that the roots that are now root bound from being kept in the small pots will not be a problem. Please help me to understand this.  Sorry for so much confusion on my part.

Now I understand after having viewed this diagram. Isee that the tuber are coming out of the stolon from the underground stem.

Turan wrote:Red potatoes will like a hilling to keep them cool and tubers from greening, but you do not need to think of more than once or so. . .I hope that helps

Boy, that is a statement I have longed to see. Thank you for saying it.

I just hill enough to keep the tubers covered.

professorm wrote:

Now I understand after having viewed this diagram. I see that the tuber are coming out of the stolon from the underground stem.

Yes, now you got it.  So one reason for hilling is to get the plant to make a longer underground stem for stolons to sprout from.  I think the stolons come from what would be leaf buds if above ground but I am not positive of that.  All potatoes respond to hilling by growing but only some will also put forth stolons along the whole underground stem.  So with red potatoes just hill enough to keep it cool and tubers covered and call it good. Your root bound issue I assume will limit the size of your tubers but that may be all. 

Sanderson, glad I could help

Thanks.

Turan you stated that "I think the stolons come from what would be leaf buds if above ground but I am not positive of that."

I found this interesting article that confirms that.




Although potato tubers ordinarily form On underground stolons,every axillary bud on potato stem has The potential to develop a tuber. Nearly a century ago,Vochting (23)demonstrated that sessile tubers developed at the covered nodes when cut pieces Of stem were inserted into soil.He also showed that
tuber formation was promoted by darkness and
moisture.
http://www.plantphysiol.org/content/61/3/348.full.pdf

  professorm   
from Kelejan from British Columbia, Canada

Thank you, professorm, for digging for that information. At least two of us have benefited from your exercise.

I also thought that potatoes were just "down there somewhere".  Not that they came from a specific part of the plant which makes sense when you think about it.

I think it quite neat that a newcomer's question can educate us here on the Forum.

Kelejan wrote:  professorm   
from Kelejan from British Columbia, Canada

Thank you, professorm, for digging for that information. At least two of us have benefited from your exercise.

I also thought that potatoes were just "down there somewhere".  Not that they came from a specific part of the plant which makes sense when you think about it.

I think it quite neat that a newcomer's question can educate us here on the Forum.

+1

Kelejan

I have to admit that I am fascinated with this  project. I am experimenting with the leggy ones that I grew in the house. I cut off the plant tops and replanted the originals again outside in my containers. Also, I am going to plant some others directly outside. I have learned so much about potatoes. It reminds me of doing research in college. Will keep everyone informed of my progress.

Chopping the potato tops .. well if there is a sharp frost & the potato tops get hit they  go black & die off .
So I Guess you can safely cut some of the tips .
Just make sure that there is some full shaped leaves left on each stem .

A few years ago whilst an ANSFG'er I  grew some spuds in the new glasshouse , in 19 inch dia tubes which were some two feet tall . Started off with the potaotes laid on 3 inches of MM and covered in another 3 ".
As soon as the tops got 8 inches above the MM I filled up the tubes so that there was 2-3 inches of green top still showing and carried on doing this little exercise till the tube was filled up .

I used an automatic watering system (  2 min of water = 5 litres every 12 hours ) and a very high grade of home made composts for the MM that was rather high in nitrogen & phosphates .

Result from :- Too much heat ( 80 to 100 oF most days , too much water ,  too much nutrients ...... I had potato tops reaching up to the top of the glasshouse roof's apex ( 8 feet tall tops ) .

 The potatoes in the tubes were little bigger than a golf ball and there was only two or three per plant tube .

 Outside potatoes in tubs and heavy duty black plastic rubble  bags fared far better ,I got a couple of 2 pounders and plenty of fist sized ones . I was watering these by hand so they didn't get too much because I had to carry it .


 One thing that has just come to mind , cutting potato tops often leads to a severe blight attack ,especially in warm humid times unless you use a copper based anti blight spray regularly .

 Our farmers here in Great Britain actually spray the crops with a very diluted sulphuric acid to kill off and dessicate the tops  within a fortnight or so . So that by harvesting time three to four weeks or so after the acid treatment  there is little chance of any blight spores from the potato tops getting on the freshly unearthed potatoes ..  This is a massive help in getting potatoes to store longer and keep a reasonable quality .


 You could put your potato plants outside along south facing wall ( heat sink effect )  in black plastic sacks like I mentioned above  and cover then each night with a fleece till all danger of frost has passed . Come the hotter weather  use a sack barrow and take them to a cooler north facing aspect etc.

I planted  potatoe eyes on June 7th and all the plants are doing well despite the crazy NJ weather. Out of curiosity, I was feeling around the surface of one of the plants and felt something hard.  I dug down about  two inches and there was a medium size red potatoe still attached. I covered it up with soil.  I was rather surprised since none of the plants have flowered and it has been about 10 weeks. They are over two feet tall and very green. Any suggestions? SHould I just leave the plant alone until it flowers and start to die back. Happy to see this red potatoe but a little confused. Is there an option for posting pictures that are not on a website? All advice appreciated. THanks.

At 10 weeks you should be finding at least baby potatoes.  Not all varieties bloom, and some varieties only bloom sometimes.  Weird I know.  If the plants are still green then let them keep going.  They will keep making more tubers for at least awhile.  You can steal a few of the bigger tubers with out bothering the plant if you are careful.


Mine did not bloom this year either and are now dying back.  Time to dig them and see what I got.

THank you Turan. I am so looking forward to turning those containers over and seeing what is there.  I will wait until they start to dry up. Finding that potatoe made my day. LOL.

I have a volunteer in a bucket that is leggy. It was a total surprise as I hadn't done anything to the bucket for months, and up it pops. It's either a red or a russet. I've been watering but not feeding. I think one is supposed to let it die off naturally in the fall, then fig around for the potatoes.

As I stated yesterday, my container potatoe plant which I planted in early JUne has not flowered, yet when I dug around the plant I felt the below red potatoe. I posed the question regarding non flowering plants producing fruit and whether I should just let it grow until it withers. Posting two pictures  now one of the potatoe and another of a plant that has been growing since May 15 and never flowered but  now it looks like it is drying. My question is (finally) what to do with the drying plant and wht to do with other plant which is very green and which has produced the red potatoe without flowering. Sorry for the repetition of the previous post

Here is a picture of the plant from mid May which is now losing leaves and drying out.