gardenorcz
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Diagnosing an unsuccessful raised bed vegetable garden

Hi,

I am posting this on behalf of a relative in Atlanta, Georgia. He has planted vegetables in a raised bed for the past two years, without success.

The bed is a 4 ft square raised bed plot, filled with bags of topsoil and miracle-gro.
The bed is south-facing but in the shadow of a neighboring house after 3 pm.
Watered 4 to 5 times a week.

I don't have statistics on the 2013 garden, but here are the numbers for 2014:
Planted one tomato plant, 1 cherry tomato plant, 2 summer squash plants, one pepper plant and one cucumber plant from seed.
All plants developed well but had no or few flowers.
Yield: Less than 2 dozen cherry tomatoes, 1 regular tomato, no squash (one plant died suddenly), no cucumbers. 3 peppers developed when the weather turned cooler.

Any thoughts on why this garden would not have produced a better yield?

Thanks.

Bobberman
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The soil needs living mater like worms or worm castings and other organic materials.. I would add some blood meal and bone meal along with composted cow manure. The fertilizer in bought top soil may be stopping the plant roots from absorbing water also. Ground up leaves or even compost will help!

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applestar
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The soil mix and fertility issue IS a point of concern, but this was the first thing that caught my eye:
The bed is a 4 ft square raised bed plot, filled with bags of topsoil and miracle-gro.
Planted one tomato plant, 1 cherry tomato plant, 2 summer squash plants, one pepper plant and one cucumber plant from seed.
I think for the size of the bed, that's two too many summer squash plants, even if one of them died off (Squash Vine Borer would be my guess) One summer squash plant could probably occupy the entire 4 ft square bed by itself, though I might try for one summer squash and two cucumber plants on a trellis.

It will also depend on the depth of the bed and whether the raised bed is bottomless/directly on the ground. (This year, I had 6 tomato plants, one seed started 2 yr old asparagus, 1 nasturtium, 1 runner bean, 1 pole bean, 1/2 dozen beets that didn't do well, and 4 garlic -- all planted in a 4x4x12" high sides directly on the ground raised bed)

Tomato production will also depend on the variety.
The bed is south-facing but in the shadow of a neighboring house after 3 pm.
How many hours of direct sun does the bed actually get? These are all fruiting crops which means they need full sun -- at least 6 hours of direct sun.

If the plants "developed well" as in grew lush and green, then there might have been too much Nitrogen and not enough Potassium and Phosphorus, especially at critical time when they should have been budding and blooming.

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digitS'
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The square foot garden regime is a little too exact and seems unnecessary for my gardens. I have just about as much space as I care to use.

The usual SFG spacing is one tomato plant per square foot. It must require attentive staking, tying up and pruning for most varieties or a choice of dwarf. Vining squash and cucumbers, are grown vertically on trellises.

The Square Foot Gardening book recommends a 3' by 3' space for zucchini. Two plants alone would be too many for a 4' by 4' bed.

Steve

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rainbowgardener
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People have mentioned Square Foot Gardening: it is a system of gardening intensively in small spaces like your friend has. But it is based in having really excellent soil, not only fertile, but loose and well draining. The mix they recommend is 1/3 compost/ manure, derived from a variety of sources such aged cow manure, aged chicken manure, kelp meal, bat guano and worm castings, homemade garden compost etc; 1/3 peat moss or coconut coir; and 1/3 coarse vermiculite.

Bagged topsoil, even with Miracle-Gro added, can be pretty much anything and is not necessarily good soil. If you look at those bags, they probably say "not for use in containers." That's because it is heavy and tends to pack down. Then there are no channels for air and water circulation. He should think of his 4x4 as a large container.

One of my guesses might be that the soil, being dense, stayed wet too much (did you have a rainy summer?) and didn't drain well enough. One of the commonest reasons for poor performance is over-watering, too much moisture.

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ElizabethB
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DITTO RBG - SFG requires a special mix of ingredients - compost, peat and horticultural vermiculite in even amounts. I have had many years of super production from my SFG except for this past year. A crazy cold winter and excessive rain left me with very little production from my garden. :twisted:

Compost is essential for SFG. MG soil won't cut it. With the proper soil mix little or no fertilization is needed. Proper planting is important - the right plants at the right time. Mature growth spacing. Vertical growing for cucumbers and tomatoes - indeterminate varieties. You can grow squash vertically as well. It takes a little practice to get it right.

Tell your friend to keep trying. Adjust the soil mix, grow vertically when possible. Be careful with night shades - tomatoes, eggplant and peppers. The are subject to soil born virus and the crops need to be rotated to a different box every spring for 3 years in a row. So a minimum of 3 boxes.

Happy gardening

imafan26
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I agree with everything that has been said. Bagged topsoil isn't really topsoil. Topsoil is what you find in the first 2-8 inches in a forest and it is loaded with critters, roots and organic matter. Bagged topsoil is probably subsoil which contains a few minerals but is poor in organic matter. Just as you would not use soil in pots potting soil does not mix well with dirt.

To grow vegetables and get good production, you need to build up the organic matter in the soil. Organic matter adding 2-4 inches every time you plant replenishes what is lost mainly through harvesting activities. Compost also sinks over time as it decomposes to feed the soil organisms. Organic matter will help hold on to moisture as well as help to improve drainage. If the raised bed drained well then it may be enough, or add coarse sand to 1/3 of the volume of the bed for drainage if it got pooled a lot.

You can start with manures, blood meal, bone meal, fish meal etc if you want to be organic, but it takes about 3 years to get production to be competitive with synthetics.

You did not mention adding any kind of fertilizer, either synthetic or organic or if he was using miracle grow. Plants can be grown closer together in a small space but it takes planning and diligence to make sure each one has enough growing room and enough nutrients so they don't starve. There should be some starter fertilizer and supplement based on plant needs. If he gets a soil sample tested, your local extension will make recommendations. Mine gives recommendations based on 100 sq ft, but some labs will give recommendations per acre so you need to do some math. If you want organic, then request organic recommendations.

He should not have needed to water 4-5 times a week unless he watered shallowly. If the beds are watered deeply, they should be able to go a few days before needing water again unless it was extra hot or windy. Deep rooted plants are more vigorous and withstand stress better. Again more organic matter and mulching would keep down weeds and reduce the water loss.

Finally location, is important for the kinds of plants you are growing tomatoes, squash and cucumbers. They all like to be in full sun for at least 6 hours a day. If he cannot get that much sun, then it is not the best location. South facing is best and away from any shadows cast by things like buildings or trees. You said the plants grew well but did not produce flowers or fruit. Usually that happens when 1) they get too much nitrogen and produce green at the expense of flowers and fruit 2) there aren't enough hours of light.

If the plants were given high nitrogen and little else they would be lush. But, saying that, I over feed my tomatoes; they are 8 ft tall but in full sun they still produce a lot of fruit and I do not prune them.

If this is the only place he can build the garden, he may have to choose plants that will grow in less light. If he gets at least 4 hours of light there are some leafy greens and herbs that will tolerate that or if he can relocate to where the garden can get at least 6 hours of sun, that would be better.

a 4X4 garden can produce enough vegetables for one person if it is planted well. For such small gardens I would plant things that don't require a lot of growing space. I plant my cucumbers on a trellis in my main garden, but tomatoes take up too much space so I plant them in pots elsewhere where they can get the room the need and I save the space they take up for other things in the garden. Zucchini takes up a lot of space. I only put in two plants and they took up a 2 x4 ft space in my garden and half the plants were hanging over into the pathway. I did not get that many zucchini because they got stung a lot and they were not parthenocarpic seeds so the flowering was not syncing well. My cucumbers are parthenocarpic so they usually produce well.

Finally, cultivar selection matters. It is best for a beginner especially to stick with cultivars recommended for your location. After you figure out the plants basic needs, you can experiment with different cultivars. If pollination is an issue for things like cucumber and squash, get parthenocarpic seeds which do not require pollination to produce fruit. Tomatoes are wind pollinated as well as insect so it is less of an issue. But in humid climates some tomato pollen will become sticky and won't set fruit as well. BTW, if you live in a hot climate, you need heat resistant cultivars or tomatoes will stop producing. Cherry tomatoes are more heat tolerant but even they will stop producing when it gets hot enough.

gardenorcz
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Wow - These are great responses, offering a lot to think about. My relative is reading all of it, and I hope he will have a better yield next year. Thank you.

jrcmillett
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@imafan26 Can you please explain: what is a cultivar?

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rainbowgardener
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A cultivar is a variety of a certain plant that has been bred to have certain characteristics. There are roughly a million tomato cultivars ( :) well maybe not, but lots and lots). When you see variety names like Tomato Brandywine, Tomato Big Boy, Tomato Cherokee purple, etc those are all cultivars. They are not separate species and can readily cross breed with each other and revert back to type.

The scientific name of the plant is written genus species var. (variety) xxx. For tomatoes that would be Solanum lycopersicum var. Cherokee purple (or whatever). Solanum means it is in the nightshade genus. Lycopersicum is latin for wolf peach. It is the same root as lycopanthy which meant werewolf-ism. When tomatoes were first introduced to Europe, they were thought to be toxic as other nightshades are and were thought to be associated with witchcraft, werewolves, etc.

Here's a little fun history of the tomato:

https://www.tomatoesareevil.com/tomato%20history.html

Probably more information than you were looking for when you asked the question, :) but I love the stories behind things.

turfdr
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Awesome article Rainbowgardener!!!!!!!!!!!!

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digitS'
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Lies! All lies, RainbowGardener!

Those olde Europeans wouldn't have known decent Native American food if it jumped out of the bowl and bit 'em!

They came to North America and still didn't have a clue. Lucky for them that some Italian Americans showed up and cooked them something! Italian ...?

Personally, I like those Japanese golden cherry cultivars real well.

:) Steve

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rainbowgardener
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Europeans did not know the New World foods until the Age of the Explorers when Christopher Columbus and all the ones that came after him started bringing them back to Europe. And right indeed, they still didn't know what to do with them and were slow to adopt. We think of Italian cuisine as being tomato based, but it wasn't at all before tomatoes were brought back to the old world, and tomatoes weren't fully accepted in Italy until in to the 1800's. ...

New World foods that were unknown to Europeans until the age of explorers include corn, potatoes (think of the Irish and their potatoes!), tomatoes, pineapple, chocolate, chili peppers, and many other things we now consider basic around the world.

imafan26
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That's right Rainbow. But, once a thing catches on the culture adopts it as its own quite rapidly so that a hundred years later, it can be so ubiquitous and ingrained in the culture that it seems like they had it forever.

Just like the first and still my favorite spaghetti sauce is still Bolognese which is tomato based. The tomato which comes from Central and South America made its' way to Europe where it was eventually adopted by the Italians and then made a round about return via immigrants coming to Canada and America.
I believe the first tomatoes that Columbus discovered weren't that good. It took a lot of time and patience to develop it into all of the different varieties of tomatoes that we have today. Some of them are still not that good, but others can be great.

Pineapples are associated with Hawaii, but it came from South America and is not a native plant. It was a principal crop of Hawaii second only to sugar cane. Most of the sugar and pineapple plantations have shut down and only a few fields of pineapple are still grown mainly for the fresh market.

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digitS'
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Notice how quickly tobacco was adopted.

The Jamestown people even experimented with jimsonweed!

If it is truly risky, somebody will decide that it's worth a try.

Steve

Vanisle_BC
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applestar wrote:This year, I had 6 tomato plants, one seed started 2 yr old asparagus, 1 nasturtium, 1 runner bean, 1 pole bean, 1/2 dozen beets that didn't do well, and 4 garlic -- all planted in a 4x4x12" high sides directly on the ground raised bed
Applestar, I just came across this and was surprised at the amount you grew in that 4x4 bed. Could you give some idea of the spacing pattern and support systems you used? My bed sections are 3.5x4 feet and for tomatoes I limit them to 6 plants giving each a little over 2 sf., with nothing else planted in the section. Though your beds are a bit wider I have trouble imagining all those extras - garlic, beans etc, fitting in. Even if availability of nutrients was not a problem, I imagine "structural management" of the plants could be challenging. Would appreciate any details you can give.

I'm pretty new here but already I appreciate your many informative posts.

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digitS'
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Do you think that AppleStar has densely planted garden beds, Vanisle_BC?

We are all curious how she has planted her winter Bedroom! Entire house. Garage. Neighbor's Guest Room!

;)

Steve

imafan26
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Yeah, Apple has a jungle. She must have a really big house or it must be a maze in winter getting around the plants. Applestar experiments with hundreds of tomatoes, I have room for three (and it is all I need anyway) and so many other plants. Her garden must be bigger than I imagine from the pictures. What are the dimensions Applestar?



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