12

I don't quite understand why so many tutorials, photos and videos show people planting a bunch of seeds together in one hole. Is there some benefit to this?

I have very little experience with gardening, but common sense tells me that planting just one seed per hole is the efficient thing to do. Somewhere I heard that plants grow better in distance from other plants because they get more water, sun and minerals from earth that way, which totally makes sense.

I can totally understand the desire to ensure that at least one seed grows into a healthy plant from a hole by putting multiple seeds in it, but that doesn't seem like a rational use of seeds.

Are there any other benefits to putting multiple seeds in a hole besides that?

user1306322
  • 747
  • 2
  • 5
  • 14

9 Answers9

11

You determine how many you want to put based on the germination rate. You should perform a germination test to what percent of the seeds sprout. If half of the ones you sow sprout. Then you plant multiple seeds into a hole.

Generally if you plant multiple seeds into a hole, if both plants grow out you will have to cut, kill or transplant the secondary (usually weaker) plant.

A third reason to plant multiple seeds into a hole is companion planting where plants that are next to each other provide some benefit (such as repelling pest, fixating nitrogen, or providing a climbing stalk) for their neighbors.

user3084006
  • 441
  • 3
  • 10
7

Eliot Coleman talks about planting multiple onions, beets, or similar other crops in the same planting hole. The end result is that you get multiple small plants from the same place -- e.g. three or four mini beets instead of one large beet, which may be more enjoyable or more marketable.

As @Bamboo's answer said, another reason might be that you are going to thin plants if more than one comes up. I've also done this with old "last chance" seed that I was pretty sure was going to have a poor germination rate. I was pretty sure that not all of the seeds were going to come up, so I just put a few seeds into each planting hole. This makes it so that there aren't gaps in the planting area, and it didn't matter that I was "wasting" seed since I'd have thrown it out anyway.

bstpierre
  • 41,452
  • 7
  • 111
  • 235
6

I use this method to grow Datil Pepper plants that are nearly 4 feet tall. When you plant 5 or 6 seeds in one spot, 90% of them germinate and begin competing for resources in the soil. the strongest plant usually prevails, and sometimes grows in unison with a second plant, nevertheless growing to a huge size with very strong stems. Each of these plant yield about 1-1.5 lbs (.7 kilograms) of peppers in it's 3 month fruiting cycle. These plants die with the first winter freeze. I collect the seeds from the strongest plant and restart the process in the spring, around March-April. (I live in North Florida.)

I hope this helped to answer your question.

Bobby Engel
  • 61
  • 1
  • 1
4

I used to work planting onion seeds in plug trays on a farm. They found that small onions sold better than giant onions, I think due to portion size when cooking. So I would sow 3-4 seeds in each plug to ensure small plants grew into a valuable crop.

Nic
  • 1,043
  • 5
  • 18
3

Germination rates are not always accurate, let alone in every kind of soil. Some soils are difficult to germinate seeds in, and if you just plant one seed in each hole, you may get no plants at all in any holes. If your season is short, you may not have time to try again effectively, especially where plants take weeks or months to germinate.

If you're not familiar with how well seeds germinate in your soil because it's the first time you've tried that seed source in your soil, planting lots of seeds can be helpful, for insurance, if you like insurance.

As an example, I direct-seeded lots of okra seeds per hole (four holes for each of six varieties), and I only got germination in six of the twenty-four holes (well, maybe eight or nine, but some of them died). If I had only planted one seed per hole, I might not have gotten any, statistically speaking. I also planted all the peanut seeds of two packs, and so far I only have one plant. The corn, squash and cucumbers on the other hand, had better germination. I imagine it's just a difficult soil for some plants to sprout in. There's probably a nutrient issue. Also, it's a different sort of climate. I imagine wetter, less desert-like areas would be easier for germination with direct-seeding. I could have had better rates if I started them in small containers in the greenhouse (or indoors).

Anyway, when I save seeds this year, I imagine those seeds will be more disposed to sprout in our soil than the parent seeds, which were grown elsewhere.

Now, to answer your question (because I haven't really done it, yet), there are other reasons to plant multiple plants per hole, in a variety of contexts.

  1. Some plants need a pollinator. Growing two or more in the same hole can potentially help with that. Some plants do better than others in this situation.
  2. Some plants will be smaller while growing with another plant, and still produce fruit, whereas they might be huge otherwise. Tomatillos are an example here. If you want smaller plants, this may be helpful.
  3. If you're breeding plants, it helps to have lots of plants. If the traits you're selecting for show through when they're planted together, this can save you space and time. There's a lot to be said for genetic diversity, even within the same variety.
  4. Some plants don't seem to suffer from being planted with another. However, they may end up using soil nutrients faster, and may suffer as a result at the end of the season.

In my experience, you can have at least up to three cucurbits per hole with decent results. Tomatoes usually like to have their own space, though (at their final transplant location; starting lots per container inside before the transplant and then dividing them at transplant time can work if you know what you're doing). Physalis don't seem to mind much being planted with lots of seeds per hole.

Brōtsyorfuzthrāx
  • 17,794
  • 4
  • 27
  • 65
3

Hmm, well I'm desperately trying to think of any time I've seen a whole bunch of seeds shoved into one small hole, and I can't. Generally, with larger seeds, they are planted individually, though possibly close together if in a seed tray just for germination and growth initiation purposes, and smaller seeds are broadcast across the top of the growing medium. Planting straight into the ground with larger seeds (like nasturtium) you may put 2 seeds to a hole and remove one plant later if they both grow, but smaller seeds are either sprinkled lightly in pre prepared furrows or just broadcast onto friable ground, depending on what it is you're growing.

I'd like to know where these tutorials, videos and photos are showing this method of sowing, because in all my 35 years of being in horticulture, I've never seen it nor been advised to do it, so I'm wondering what on earth the purpose of this might be, and curious as to whether it's something useful that I don't know.

Bamboo
  • 131,823
  • 3
  • 72
  • 162
2

If you are confident of a high germination rate then you can plan one seed per hole. With that strategy, would waste less seeds but risk the chance that that particular location may be underutilized if the seed does not germinate. The main reason people plant multiple seeds in a hole is to ensure that something grows in the designated space to ensure maximum utilization of space and produce while sacrificing a few seeds. So, it is really a trade-off depending on what you want to maximize and how confident you are with the germination rate.

JStorage
  • 7,844
  • 6
  • 32
  • 72
1

germination rate: in my experience commercially purchased seeds sprout very roughly about

2 years later - 90%
3 years later - 70%

seed size: as always, @Bamboo is hard on point. Large seeds need burying, we're not even talking tulip or lilium but rather things of Ø~2mm. My carrots and lettuce sprout after throwing away some seeds over the dirt and then watering in a way that it disturbs the soil - thus burying the seeds shallowly.

too many plants: this is always the case. The three options I know of are

  • thin out
  • replant
  • have zero yield.

And to finally address the question in some way. If the seeds are less than 2 years old, I would plant 2. Else 4.

Vorac
  • 1,083
  • 1
  • 8
  • 16
0

You can plant more than one seed per hole. But make provision for possible competition for nutrient especially for plants that are heavy feeders.

Sylvester
  • 1