User avatar
Gary350
Super Green Thumb
Posts: 7396
Joined: Mon Mar 23, 2009 1:59 pm
Location: TN. 50 years of gardening experience.

Some Plants don't like competition! What does that mean?

For years I have heard, some plants don't like competition. I always though maybe that means plants don't like crowded roots? I never really knew what means. I guess I am a slow learner, I never really knew for sure what this means. If roots from 1 plant touch roots of another plant do both plants know there is competition so they grow smaller crops?

I found a YouTube video at the very end of the video it explains what competition means. If you plant onions 4" apart there is a certain about of moisture & fertilizer for each plant. If you plant the same onions 6" apart their is 2.560 times more moisture & fertilizer for each plant. Onions planted 6" apart could grow 2½ times larger onions compared to onions spaced 4" apart.

Potatoes planted 9" apart instead of 6" apart will have 2.250 times more moisture & fertilizer per plant.

Garlic planted 6" apart instead of 4" will have 2.5 times more moisture & fertilizer per plant.

Corn planted 9" apart instead of 6" will have 2.25 times more moisture & fertilizer per plant.

Video also says, there is a happy place where extra spacing does not produce a larger crop. Is corn capable of growing 2 times larger, probably not, maybe 25% larger.

Video also said, if you plant 2 identical size onion beds, only difference is, 1 bed is 4" spaced onions, the other bed is 5" spaced onions. Both beds produced about 70 lbs of onions. 5" spaced onions are larger heaver onions so it takes fewer onions to = 70 lbs of onions. What size onions do you want?

imafan26
Mod
Posts: 13961
Joined: Tue Jan 01, 2013 8:32 am
Location: Hawaii, zone 12a 587 ft elev.

Sometimes it is nutrients, other times it is root space or even air space (sun). The more crowded plants get, the more competition there is for all of these resources. Root crops like beets and carrots need the space for the roots to grow. If you are inter planting and some plants grow faster than others, the shorter plants can't get enough light. Even if you are planting the same thing, like trees in a forest, only the most vigorous ones will survive.

For other things, they must send some kind of signal to other plants. Sun flowers and some trees prevent other plants from growing near their roots. Fennel and dill are great plant for attracting beneficial insects, especially lady bugs and lady bug larvae, but once they bloom, they can stunt the growth of plants within 10 ft of them. It is why I have to keep my fennel only by plants it won't bother like horseradish, gynuura, and ginger. I actually want the fennel to bloom since the blooms support so many beneficial insects.

Ideally, even square foot gardening spacing is too tight for me for some crops. It depends on you pruning and keeping plants in their space, like tomatoes. My tomatoes take up way more than 1 square foot and I don't like to prune them because the leaves are needed to keep the fruit from being sunburned. Hopefully, it can also hide some fruit from the birds too (wishful thinking).

I was offered some broccoli seeds and cauliflower seedlings yesterday. However, it is really late to plant them since they will be heading up in hot weather. Broccoli also takes up a lot of space. Even planting them 18 inches apart, the leaves still touch and they are better at 20-24 inch spacing. It just takes up too much space in the garden. It is why I keep most of the bigger plants in pots that I can move if they need more space.

At some point, plants will reach their limit in size with adequate spacing. But , for me day length as well as the soil nutrients also play are part in plant size. I can get tomatoes close to a pound, but not much larger because of my short day length. I can get massive plants because of the richness of the soil. I have so much nitrogen in my soil that even though I don't add much, I have massive leaves and roots are relatively small. That is why I am growing the carrots and taro (well taro has to be in pots for other reasons), in pots. In pots, I can make the soil more alkaline and adjust the nutrients to suit growing roots better. I have to grow ginger in pots to contain them, but also because they cannot tolerate nematodes.

SQWIB
Greener Thumb
Posts: 970
Joined: Tue Feb 16, 2016 9:21 am
Location: Zone 7A - Philadelphia, PA

Here's what I have Learned.
Research and Learn as much as you can.
Now take all that research and what you learned and toss it out the window.
Now, Start planting and see what works.

I got tired of the contradiction out there.
Companion planting research is one that has boggled my mind, some sites would say never plant this with that, then another site would say completely the opposite.
Don't Like wet feet
Don't Like Crowding
Don't Like competition
yada yada yada

I plant it and if it grows I'm Happy.
I think I'm more particular about my soil then I am about my plants.

imafan26
Mod
Posts: 13961
Joined: Tue Jan 01, 2013 8:32 am
Location: Hawaii, zone 12a 587 ft elev.

Companion planting does have its roots in anecdotal evidence. I agree, I have often found that different sites give conflicting recommendations.

It is true that experience is the best teacher.

However, I have found companion planting to be useful with some caveats

Dill and fennel are usually fine with most other plants until they bloom. Then they can stunt other plants around them. In the meantime they can offer benefits as pest traps and deterrents. Even though they can stunt plants near them once they do bloom, they still provide nectar and pollen for many beneficial insects. So, I plant them in the garden for their benefits but keep them at least 10 ft away from plants that will be affected by them once they bloom.

Some plant combinations are just common sense. Plants that need the same water, soil, and climatic conditions usually will work well together. Plants that occupy different spaces (root vs leaf) and use different nutrients don't compete with each other if there is adequate water and nutrition for the both of them. Inter planting a short crop of lettuce or radish in the space between long maturing big crops like tomatoes and eggplant, maximizes the yields. The long and usually large crops need to be planted far enough for them to have room to grow, but while they are young, shorter crops of 21-40 days can be grown and harvested before the larger plants get big enough to need the space for themselves.

Some plant families just don't get along. It may be because they require different soil and water needs or just because they don't like each other. I have found this out the hard way.

For crop rotation it is easier if you have the beds and space to rotate sections with different families of plants. It works out most of the time, but not always. Parsley, dill, fennel, and coriander don't really like to be next to each other especially when they start to bloom. Members of the same family will usually have the same pests, so if you have problems, everything in that family may have problems.

I do have to depend on companion planting because my garden is small. Rotation does not really keep pests from moving across the yard. So, a true rotation for me is to rotate out of a problem crop for 2-3 years or plant a more resistant variety. Rotation does work as far as soil nutrient and soil borne diseases are concerned.

I do find it helpful to separate plants that have the same pests so that maybe one of them could be saved. Whenever I plant zucchini, I lose more cucumber and bitter melon to melon flies. If I don't have zucchini, I don't even have to bag the cucumber in most cases. When I separate the zucchini and cucumber by 10-15 ft, it greatly reduces the melon fly damage to the cucumber and bitter melon.

I inter plant so that I can maximize yields in a small space. I try to space out plants in the same family just because I do not like to set up a buffet for pests who will just go down the line and consume one cabbage after another if they are planted in a row. Lettuce is a short crop and it is best planted between other crops or as under plantings in containers. I can't eat that many heads at one time and putting them in as fillers when I take out plants or redo pots, works for me.

Even companions that should go together does not always work. Even companions will compete with each other if one is at maturity and does not allow the other plant space or nutrients to get established.

I think after a while many gardeners figure out what grows best in any section of their garden. As long as the plants do well, they plant the same thing there over and over.
The only time they are forced to change will be if they encounter serious problems.

However, it is not a bad idea to change things up once in a while just to try something new. Tried and true varieties can make you complacent. It is actually hard for that to happen to me because I do live in a pest paradise and the introduction of basil downy mildew and TYLCV in 2009 has forever changed what cultivars of basil and tomatoes I can grow.

Climate change is affecting what I grow and even when I grow it. Seasons are subtle here, but we do have seasons. Right now the popcorn oncidium orchids are blooming two months early. I have araimo with leaves that are starting to yellow, and will probably need to be harvested in about a month. I had to plant the ginger a month early in March, because the buds were starting to sprout. Even though it is still cold, there have been warm days mixed with the cold fronts, so even the peppers and eggplant have continued to produce fruit. Normally, they don't like to flower when it is cold. The fruit does grow slower.

I have had to look for new varieties of plants with better disease and heat resistance. I am planting more of the tropical vegetables that are better suited for my climate and less work, and more Asian vegetables that give me better yields and have longer seasons than temperate crops. There are more TYLCV tomatoes being developed but most of them will not set in the heat. I am still waiting for a downy mildew resistant sweet basil that tastes good or a GMO variety since it has been 10 years and conventional breeding has managed to change the taste but only created a partially resistant basil that looks like sweet basil but tastes more like Thai basil.

Many of my plants have new companions now. Some are getting along and some are being bullies. I like most of the new varieties I have grown, although I still miss some of the old ones I can't grow anymore. I will find out what makes good companions over time with a little trial and error. In any ecosystem there will always be winners and losers and niches for something to grow.

User avatar
Gary350
Super Green Thumb
Posts: 7396
Joined: Mon Mar 23, 2009 1:59 pm
Location: TN. 50 years of gardening experience.

It is true that experience is the best teacher. Experiment to see what works best for you.

I think a lot of conflicting information has to do with, geographical location, different soils, different weather. What works good in Michigan may not work in Texas.

We grew 300 lbs of new potatoes from a small crop in Illinois without trying but I can't do that in TN. IL temp seldom got above 90° and they had a 10 minute rain every day about 4:30 pm. TN is 100° and we seldom get more than 2 rains per month June to Oct garden is dry as desert.

My father grew good onions when he lived near Chicago but could never grow onion after he moved to southern Illinois.

Some people know how to grow certain things but don't know why. The magic trick is to learn what each plant likes best.

Vanisle_BC
Greener Thumb
Posts: 1354
Joined: Mon Apr 13, 2015 9:02 pm
Location: Port Alberni, B.C. Canada, Zone 7 (+?)

SQWIB wrote:
Thu Apr 01, 2021 12:04 pm
Here's what I have Learned.
Research and Learn as much as you can.
Now take all that research and what you learned and toss it out the window.
Not always valid but there does seem to be a fair amount of garden folklore masquerading as fact; even contradicting itself, sometimes within a single statement.

There's the oft-repeated advice that the biggest garlic cloves grow into the biggest bulbs. I've tested this more than once and found it false; not just unreliable, - quite wrong (but I check year after year in case I'm missing something :)).

Then there's the thing about hilling up potatoes. I've read that this is done to keep them from being turned green by sunlight; then that it's because, as the stems grow higher they have to be kept buried so that more potatoes will grow on them (although elsewhere it said the potatoes will all grow at the same depth.) Then there are supposedly determinate & indeterminate varieties and only indeterminates need to be hilled. And you have to leave 3 feet between rows because you need to walk there; or it's because that's the only way you can pile enough soil to hill them up properly; or hey, planting them 12"x12" is just fine.

Tomatoes have to be grown with long stems then transplanted with those stems buried because roots will grow from them and make a more productive plant. I've been doing this but I see no improved yield compared with the early years when I didn't "know" about this.

Some of this 'news' has to be 'fake' but people believe it fervently. Luckily stuff often just grows anyway
I plant it and if it grows I'm Happy.
I think I'm more particular about my soil then I am about my plants.
"In theory, practice is the same as theory. In practice, often it's not."

User avatar
Gary350
Super Green Thumb
Posts: 7396
Joined: Mon Mar 23, 2009 1:59 pm
Location: TN. 50 years of gardening experience.

Vanisle_BC wrote:
Thu Apr 01, 2021 7:57 pm
SQWIB wrote:
Thu Apr 01, 2021 12:04 pm
There's the oft-repeated advice that the biggest garlic cloves grow into the biggest bulbs. I've tested this more than once and found it false; not just unreliable, - quite wrong (but I check year after year in case I'm missing something :)).

Then there's the thing about hilling up potatoes. I've read that this is done to keep them from being turned green by sunlight; then that it's because, as the stems grow higher they have to be kept buried so that more potatoes will grow on them (although elsewhere it said the potatoes will all grow at the same depth.) Then there are supposedly determinate & indeterminate varieties and only indeterminates need to be hilled. And you have to leave 3 feet between rows because you need to walk there; or it's because that's the only way you can pile enough soil to hill them up properly; or hey, planting them 12"x12" is just fine.
I have experimented with determinate & indeterminate potatoes and I can not tell there is such a thing as determinate & indeterminate potatoes they all grow like determinate potatoes.

I read new potatoes grow below the cutting & videos sometimes say new potatoes grow below the cuttings. I have planted many cuttings then carefully dug up new potatoes they are almost always above the cutting. Last summer I carefully dug up 50 Kennebec potato plants, 48 plants had all the new potatoes above the cuttings. The other 2 plants had 1 potato below the cutting with 2 or 3 new potatoes above the cutting. I dug up 20 red Pontiac potatoes new potatoes were always above the cuttings. I use to plant a lot of Russet potatoes, I will grow some this year.

My grandfather in IL use to plant cutting about 1" deep, 8" apart in a 3ft wide row about 40ft long. He only covered potatoes with about 1" of soil. NO hill. It took about 1 month for new potatoes to start growing. As new potatoes grew larger and pushed up the soil he tossed about 1" of soil on each potato to make sure potatoes were protected from sunlight. When plants died there was 300 lbs of potatoes to dig up.

I see lots of information that claims each potato plant will make 3 lbs of potatoes. I can only get 1 lb of potatoes in TN per plant. We probably got 3 lbs of new potatoes in IL from each plant.

I have heard big garlic grow best & also heard small garlic grows best. I need to test this to see for sure.

Farmers in Wisconsin have best crop planting yellow dent corn seeds 4" apart. Farmer in southern IL have best luck growing corn with seeds 5" apart. It is hotter & less rain in IL. Wisconsin gets a lot of rain.

imafan26
Mod
Posts: 13961
Joined: Tue Jan 01, 2013 8:32 am
Location: Hawaii, zone 12a 587 ft elev.

I have grown garlic from big bulbs and smaller ones. Garlic does not grow well in Hawaii with short days. Long day garlic cloves are smaller than the ones I started with and short day garlic made small bulbs. I've decided that it is better to just buy my garlic from the store.

I have not grown potatoes, I would rather grow sweet potatoes in my climate and the leaves are edible too.

As for tomatoes, I bury the tomato transplants deep and only let the top four leaves stick up above the soil. I don't know if it helps with growth or not. I just don't need a lot of leg on the tomatoes in my cages (7 ft cage). All my tomatoes end up going into the ground from the drain holes of the 18 gallon pots anyway. Indeterminate tomatoes can produce up to 10 months It could have been longer, but disease usually kills them since they could be perennials here. Some tender annuals in climates with frost are perennials here.

As Gary said location and climate matters. You have to pick the right plants or cultivars for your conditions. I love Applestar's tomatoes. I did try coyote, but found that it is better adapted to cooler conditions and it did not have the disease or heat tolerance to live long in my garden.

Vanisle_BC
Greener Thumb
Posts: 1354
Joined: Mon Apr 13, 2015 9:02 pm
Location: Port Alberni, B.C. Canada, Zone 7 (+?)

Oh, here's another piece of gardening advice I haven't seen before. A website about peppers says that when seed packages recommend spacing it's meant to be the diameter allowed for roots - not the spacing between plants. So if the packet says 12 inch spacing, the seeds or transplants can be 6 inches apart giving each one a potential 12 inch root circle.

That's the first time I've heard such a statement and I'm pretty skeptical - actually more like incredulous; it sounds nutty. There's plenty more to consider about plant spacing than root spread. Has anybody else come across this?

User avatar
Gary350
Super Green Thumb
Posts: 7396
Joined: Mon Mar 23, 2009 1:59 pm
Location: TN. 50 years of gardening experience.

I found this information. I man in Wisconsin was having trouble with wind from summer rain storms blowing down his corn crop. So he started planting corn rows so they are parallel to prevailing wind. Now wind blows between the rows and corn survives better than before. Next he decides to reduce seed spacing to 5" between seeds so more plants per row will be stronger, plants will hold each other up better than before. Problem solved corn has survived year after year much better than before.

LOL, a bit funny. Prevent 20% of the corn from blowing down and crop is 5% less because it is planted too close your ahead 15%.



Return to “Vegetable Gardening Forum”