Plants not growing well

Hi there! I'm wondering if anyone can give me any advice. We started a SFG 3 weeks ago here in Central Florida and most of the seeds came up well, then stopped growing. Even the radishes have not grown past about an inch to inch and a half tall after 3 weeks. My husband tweaked the SFG design by making basically a giant earth box with pipes beneath the soil (10 inches of Mel's mix above them) and a pipe coming up to fill with water (officially these are called wicking beds - anyone heard of these?) We've been keeping it so the soil is moist when I poke my finger in - I notice the soil is pretty wet further down (starting about maybe 4 -5 inches down). We planted broccoli, collards, peas, onions and herbs - the peas are doing well and the tomatoes look good (although the lower leaves are turning yellow) but the rest is either not growing or growing VERY slowly. The radish leaves look like they are turning yellow as well. I'm wondering if the plants are getting too much water? Any advice would be appreciated - I'm getting worried about the plants all dying!

This time of year the days are becoming so short that there might not be enough daylight hours to sustain good growth even if the weather is warm. That would be my first, best guess.

Thanks for the reply - we are still in the mid-80's during the day with a good 6 hours of sunlight on the garden here in central FL - is that enough for veggies? Our other bed with lettuce in it gets less than that and is doing pretty well. Night temps are in the 60's - might that be a factor?

They should be growing. Here in So Cal. which is a higher latitude, I have no problem with plants in the winter. However, they do grow a little more slowly. Is your garden always 6 hours of sunlight because of its location? That does seem minimal. Mine gets sunup to sundown, which right now is still 11 hours.

If they are not dying, then they are growing. but you may be right - it may be too much water. Try lessening it for a few days and see what happens.

Yes, always 6, could be 7 hours of sun this time of year. We have so many trees in our yard here in Florida that we have the garden in the only spot where it gets sun. Our lettuce bed doesn't even get that much because we put it in the wrong spot when we started (novices!) but it does great anyway. So far in the SFG only one thing has absolutely died - a broccoli plant. The rest are just growing so slowly. The thing that makes me wonder about too much water is the radish leaves turning yellow (with some red) - never had that happen before. The herbs we did from seed from a company that I'm having trouble with other seeds from them, so won't get them again. Hopefully things will pick up!

Have you used wicking beds before? Was your Mel's Mix right to the best of your ability, or did you skimp somewhere? Could there be some chemical in the soil from installing the "wicks?"

I am just spitballing here. But, the yellowing and slow growth suggests some kind of nutrient issue. But, I am far from an expert when diagnosing these things.

Well, a quick search turned this statement up from About.com: "Foliage discoloration and stunted plants can easily be caused by soil that is too wet and drains poorly or soil that is too compacted for good root growth."

Further down the page, your problem may be nitrogen, too. "Nitrogen (N) •Symptoms: Older leaves, generally at the bottom of the plant, will yellow. Remaining foliage is often light green. Stems may also yellow and may become spindly. Growth slows.
•Sources: Any compound containing the words: 'nitrate', 'ammonium' or 'urea'. Also manure.
•Notes: Many forms of nitrogen are water soluble and wash away."

Magnesium deficiency apparently causes pale yellowing. Phosphorus can cause reddish tints.

I would start with these areas, but it sounds more like your compost mix was off somehow.

Wow! Thanks for the great information. I'm inclined to agree that it's either the soil not draining properly or possibly the nitrogen. We did use horse manure as part of the mix, but didn't use the full 5 types of compost, so maybe that's affecting it. I am planning to take some samples tomorrow and send them off to our extension. In the meantime, I may try adding some nitrogen and see what happens.

ksbmom wrote:.... My husband tweaked the SFG design by making basically a giant earth box with pipes beneath the soil (10 inches of Mel's mix above them) and a pipe coming up to fill with water (officially these are called wicking beds - anyone heard of these?) We've been keeping it so the soil is moist when I poke my finger in - I notice the soil is pretty wet further down (starting about maybe 4 -5 inches down).

I have heard of wicking beds. They are essentially a continuous watering sister (CWS). And you are correct, you have made the bed into an EB. I have 14 EB's and this fall is the first time I used MM in the box. I am on the verge of loosing most of my crop in the EB's with MM because the soil is over-wicking. There is so much water in the mix that I believe my plants have root rot.

I believe the high proportion of Compost in the MM is the contributing factor. I pulled the mulch covers off the boxes, to get the excess water to evaporate.

With respect to your plants in the raised beds, I believe you're putting too much water into your MM. Lower leaves yellowing is a sign of over watering. Dig down near the bottom of a square and grab a handful of your "soil". Squeeze it. Does water run out ? I can squeeze about 2 TBL out of each fistful of MM. This is a sign of over-watering. DO NOT try to adjust nutrients before cutting back on watering. Let your mix dry out and water occasionally in a more controlled amount.

Check the top of the soil as well. My top 1/2" has absorbed so much water that I can squeeze water out of it as well.

I started this experiment b/c I was told MM would not work in an EB b/c it would not wick water. That made no sense to me. I put MM in the EB with no plants and filled the reservoir with water. After two days, the at the top was still dry, but the soil at the bottom was slightly damp. After three days, the top was still dry but moisture had reached about 2" below the top. So I deemed the MM would work and planted tomatoes in several of them.

Turns out that MM keeps wicking water from the reservoir until it is so saturated, roots can't get oxygen

My tests with MM proves a drip system feeding H2O at the surface is better than a wicking system.

I've never run across anyone else who even knew what a wicking bed was! I went out today and bought some proper compost, pulled out the tiny plants that weren't thriving and replanted, digging in the compost. During the digging, I noticed that the soil was actually not as wet as I had anticipated - I definitely could not wring it out, and the top was pretty dry. I still think the watering is a factor - I obviously haven't gotten it down how much to add to the system. I did some more reading and I really wonder if it's the MM - we only used horse manure and composted yard waste because it was more cost effective. I have a couple of empty squares near the tomato plants and I'm going to dig down to the pipes and see how wet the soil down there is. Next SFG will be strictly by the book!

My wicking box design was a little different than yours, and my MM was by the book. I did not have the problems you did.
https://squarefoot.forumotion.com/t3068-sfg-wicking-boxes

Kay did her wicking boxes differently also, and had good luck with hers.
https://squarefoot.forumotion.com/t5716p30-experiment-to-deal-with-pure-sand-and-high-water-bills

Thanks for the links Boffer! You really got fancy with yours! I just talked with my husband, who did the MM for the box (he mixed it in the back of his pickup truck) and he mentioned that we did not add as much vermiculite as the book says to. Instead of one third we maybe have one fifth (he's such a not-go-by-the-directions kind of guy ). So I think that's working in our favor as it doesn't seem to be getting too wet. We're not sure if it's sopping right above the pipes or not - I'm going to dig down tomorrow and see what it's like. I haven't added water for quite some time and my measuring stick still shows about 2" of water in the pipe. I really think the problems we're having are due to not doing the right MM.

Closies are usually good enough. 1/3 or 1/5 vermiculite shouldn't make too much difference, as long as your compost is 1/3 or more of the mix for nutritional purposes.

Did you use coarse vermiculite? I have found that MM made with medium grade vermiculite holds water to the point of over-saturation. I have to water the two boxes I have with medium vermiculite differently than boxes with coarse.

I honestly don't know what grade the vermiculite was - I got it at our local feed store. It's hard to find it here. Other than the feed store, the only other verm. I could find was at Lowe's in tiny little bags that would have cost a fortune.

A question on your wicking bed - I see you lined the box with plastic. What kind did you use? My husband had a hard time finding something he thought would be tough enough (he's quite a perfectionist!)

I did it on the cheap and don't recommend my method; it had a slow leak from the beginning. I think the best way would be with 30-40 mil pvc pond liner or shower pan liner.

I think my husband ended up with pond liner in our bed. He looked at the EPDM - even found some websites that sell used billboards which apparently are made of a very tough EPDM. We have a place here that storehouses billboards after they come down but they wouldn't give him one.

I just wanted to add the there is a 1 inch space between the bottom of my "pond" beds and the top of the water reservoir. Only the wicks go into the water and the bed that was not made with cups had an excess water problem last month during heavy rains. I poked some more holes into the weed block lining the bed and it started draining again. It was fine the next day and the plants are doing well.

Kay

Thought I'd give a quick update on my original post about my plants not doing well. On Wednesday, I gave the garden a shot of liquid fertilizer, then went and bought some mushroom compost, Black Kow and another type of compost with forestry compost in it and dug it into the squares that I replanted and around some of the things I left in. Yesterday when I went out to look, I thought that things were looking greener, especially the radishes, which had gotten very yellow. (Sorry, no pictures because I don't know how to get them from the camera to the computer yet). Today, I'm sure they are greener. Also, the poor little broccoli plant I left in has already gotten a bit taller and is putting out a second little set of leaves! Woo hoo!