Hydroponic Green Beans Question

8 years ago

last modified: 8 years ago

This is my second attempt at growing green beans hydroponically. Using the Kratky method except I do have a bubbler for more air. The issue I'm having is this odd leaf bleaching and discoloration.

Air Temp is 72, water temp is usually between 65 and 68. PH is 6.23 and the ppm is 350 this time. There are a total of 4 plants and all of them are exhibiting this to some degree. From reading it sounded like a mold or mildew, but its not powdery at all and it didn't seem to look like any of the pictures I saw.

Does anyone have any idea what might be causing this? Or what I can do to stop it?

Featured Answer

hydroveggiegrow

8 years ago

That's make sense if you're seeing some underdeveloped roots since a calcium deficiency can cause that. And with underdeveloped roots comes stunting of growth. And stunting of growth will cause lower transpiration rates which will cause less calcium uptake. It's a vicious cycle.

Calcium travels into the plant with water uptake and has to be in high concentrations in your nute solution in order to maximize that uptake. Nearly all commercial nutes I've seen are low in calcium. For the most part that's because if people are using them with soil or hydro and tap water, which usually contains a lot of calcium, they assume there is another calcium source. Somewhat the same thing with magnesium. Which is why many manufacturers specifically state that if you're using RO then you should use a cal-mag as well, and of course they make one! How convenient. I figure out the PPMs and have my own formula that increases Ca to almost around my N levels and Mg to at least 80% of K. Once I tweaked my ratios I haven't had any calcium or magnesium issues at all and overall better and faster growth.

But figuring all that out for most with dilution rates and whatnot is daunting so I would start by doubling your dose of cal-mag and get some air, if you don't already, blowing on those plants to increase transpiration (water uptake). Or you could use your cal-mag as a foliar spray...or both for that matter.

Dyna-Gro makes good products, I use a few, but it's weird that they have so much phosphorous in that mix. But having said that, it's not likely you would ever get a phosphorous toxicity and that would usually just cause some issues with some of the metals.

I'd give that a go. This is all assuming that you're changing your solution at the appropriate times and maintaining pH and whatnot. Too low of pH can cause Ca problems as well as some others.

Sort by:Oldest

Comments (7)

hydroveggiegrow
8 years ago
If I had to hazard a guess I'd say calcium deficiency. I've seen something similar on my tomato plants before and it was calcium related. It's not only the necrotic spots but I can see some signs of it on other leaves - that slight crinkling and some distortion on some leaf margins.

What nutes are you using? How much Ca and NPK? RO water or tap?
Joshua Terry
Original Author
8 years ago
I've been using Dyna Grow which is 7-9-5 and adding Mag-Cal + for the calcium, magnesium, and iron. I only added about half the recommended Mag-Cal though since they were so young.

I normally use Rain Water that I harvest into barrels for the water.

I confirmed its definitely not White Powder Mold or Mildew. We have a bush outside with it and its nothing like it. The spots are completely devoid of color almost like its been bleached. It doesn't seem like its spreading to the new leaves yet.

One of the 4 plants seems oddly stunted as if frozen in time. I started all of them at the same time, but 1 of them seems like it just stopped growing after 2 leaves. It looks fine and healthy except that it appears about 2 weeks behind the others and has no visible roots from the bottom of the cup.
Related Discussions
questions about growing bush green beans in containers
Q
Comments (13)
Unfortunately I haven't really received an answer to my question. I plan to space them how far apart each plant should be spaced. OK. I would prefer to use a window box, so however many gallons the thing has to be to plant 4 green bean plants without overcrowding them, please specify the dimensions of the window box and what size it has to be in gallons. 6" deep, 6" long and 6" wide. I assume since I'll be planting 4 bush green bean plants and this is how many I want in a container without overcrowding them after I thin them, that I should plant double the amount of seeds with the number of plants I plan to grow since I'll be thinning them out to the strongest plants later? First, the idea of thinning to leave just the strongest plants is silly. What criteria determines which plant is strongest? Sometimes the little weaklings go on to do impressive things once they reach their stride, and the rapid growers peter out and become weak, but I digress. If you will only be planting 4 bush bean plants it isn't really worth your time. You will, at best, get 1-2 light side meals from that amount. Bush beans are usually planted with 3-6" spacing. Root system crowding/competition is pretty much never a limiting factor for them, instead sunlight exposure is. If you plant them too densely the ones in the middle shaded by the sunny side ones become the primary limiting factor. In a container you have the luxury of rotating it for sun exposure so you can plant a little more densely than in the ground. In a trough style container you can go even more dense since the mass of leaves is only as wide and the narrow container. If it were me and I was using a container 30" long by 6" wide by 6" deep I would place 20 bush bean plants into that space. That's 3" per plant. I would also fertilize with a 3:1:2 ratio fertilizer such as Miracle Grow 24-8-16. Don't count on the myth of beans/legumes using atmospheric nitrogen when growing in containers. Heck, half the time you can't even count on it when growing in the ground. With a trough shaped container this amounts to 2 rows of beans and I would rotate the container every day or every other day to get both sides adequate light.
...See More
Brocolli and green bean question
Q
Comments (5)
Here's an idea for the beans -- do as you say, pick clean, water, do a rain dance or two, and hope they start over on HALF of your plants. On the other half, leave them and let the beans dry, and at least you'll be certain of having dry beans for chili this winter, even if you don't have lots of quarts of canned green beans. My broccoli is also inedible because of the heat and drought. If you keep broccoli from going into full flower and setting seed, it will keep on sending up side shoots (trying to reproduce). You can keep cutting (not to the ground, just the heads and then the side shoots, as mentioned above) and hope that the cool of fall will improve the flavor of the side shoots that are produced then-- it does do that most years for me, also in zone 5. Good luck!
...See More
questions on kale, peas, green bean and tomato
Q
Comments (8)
All bets are off for green house or house grown plants. For open field growing. All fruits are perennials and most vegetables are annuals or biennials. There are many tropical perennials in the vegetable group but in most of North American , they are grown as annuals. That includes fruiting vegetables like tomatoes and peppers and root vegetables like sweet potatoes. Kale will go until it sends up a seed head, which normally happens in the spring ( increasing daylight) It will stand mild freezes but not hard frozen ground. Peas (Pisum) like cool damp weather. tolerate frost but not hard freezes. Beans go down with the first frost. In the south heat can be a problem in midsummer for many crops, but should not bother you in New York State. I doubt that you ever see 30 or more days of triple digit temps. There are many annual flowers, even perennials have their season. I doubt that you have roses blooming in january unless you are using a green house. In general tho, treat your vegetables as you would annual flowers and you will be ok.
...See More
Green bean question
Q
Comments (3)
The trouble with planting things now is the heat. If you plant anything be sure to keep them well watered so they sprout. Take a hint from my Italian neighbor. He grows new beds of lettuce all summer. He waters well and then covers it with a piece of cotton material which he soaks then waters every day. The material keeps the sun from drying the earth so much. He removes the cloth after the seeds have sprouted. You can plant anything that will mature before frost. That is probably beans but not carrots. You may have to do some covering up when frost threatens. Check the seed packages. They usually give you the days to maturity.
...See More
Joshua Terry
Original Author
8 years ago
I did not realize you could use Cal-Mag as a foliar spray! I haven't used any sprays yet as I wasn't quite sure of their effectiveness. I will have to try this.

I will say that since I have increased the amount of Cal-Mag in the solution they do not seem to be getting worse. I had hesitated adding too much initial as I had read that a common beginners mistake is too add too much.
hydroveggiegrow
8 years ago
The damage on the leaves that's already there won't go away so just pay attention to new growth and growth that's undamaged and keep an eye on it.

Tell tale signs of calcium deficiency are "j-hooked" leaf tip, basically tips that curve left or right, distorted new growth, or cupped leaves (up or down, but I most the time see up).

I wouldn't worry about giving it too much cal-mag. I've never seen a calcium or magnesium toxicity in any of my plants and run high levels compared to most although some elements are antagonistic and will interfere with the uptake of others but generally nothing to worry about with Ca and Mg.

Give me an update after awhile if you don't mind. I'd like to know how it's working out.
Joshua Terry thanked hydroveggiegrow
Joshua Terry
Original Author
8 years ago
Your advice made a tremendous difference! I started adding more CalMag to the Nutrient solution as well as creating a foliar spray which I've been using on Beans, Tomatoes, and Peppers. I've seen improvement in everything since began using it.

Here's a picture of one Green Bean plants now. You can still see the one damaged leaf but all of the new growth appears very healthy with a good deep color.

Thank you very much for this advice, it has really helped!
hydroveggiegrow
8 years ago
That's great to hear. Glad I could help.

Hydroponic Green Beans Question

hydroveggiegrow

Comments (7)

hydroveggiegrow

Joshua Terry
Original Author

Related Discussions

Joshua Terry
Original Author

hydroveggiegrow

Joshua Terry
Original Author

hydroveggiegrow

COMPANY

BUSINESS SERVICES

GET HELP

CONNECT WITH US

Hydroponic Green Beans Question

hydroveggiegrow

Comments (7)

hydroveggiegrow

Joshua TerryOriginal Author

Related Discussions

Joshua TerryOriginal Author

hydroveggiegrow

Joshua TerryOriginal Author

hydroveggiegrow

COMPANY

BUSINESS SERVICES

GET HELP

CONNECT WITH US

Joshua Terry
Original Author

Joshua Terry
Original Author

Joshua Terry
Original Author