When you’re gardening in a small space, you need to get creative. Spacing is something that new gardeners are often confused about because the directions on the seed packet are often meant for large-scale farming. I discovered multi-sowing when I started learning more about intensive gardening, and it’s been a method that has been very productive for certain crops.
Multi sowing is a simple method of obtaining more seedlings within the same cell when starting your seeds in trays. Simply sow a number of seeds (usually from 3 to 8), and don’t thin the seedlings. Plant them outside at the recommended spacing for one plant, and they will grow in clumps.
Multi-sowing isn’t a method that can be applied to all kinds of vegetables. If you’re worried that not thinning your seedlings will affect your plants’ growth, that’s usually right. However, there are certain crops that thrive when being sown in clusters, and those are exactly the ones you need to know about, so you can get a better harvest.
What vegetables to multi sow
Multi sowing works impressively for plants with roots or bulbs that develop above the ground, such as beetroot, radish, leeks, and onions. However, plenty of leafy greens and herbs do very well without any kind of thinning.
Here’s a comprehensive list of all the plants I’ve successfully grown with the multi-sown technique:
- Onions for bulbs
- Spring onions
- Peas for shoots
- Peas for pods
- Dill, Parsley, Basil
- Looseleaf lettuce
When multi-sowing these plants, the general rule is to sow 4-6 seeds for larger plants and 6-8 seeds for smaller plants, such as leafy greens or onions for salads. Later on, you can discard some of the weaker seedlings by pinching them at the base. This way, you’re left with the exact number of plants you want in your cluster.
Beets, radishes, and onions grow nicely when sown in clumps, because, as they’re developing their roots and bulbs, they are pushing each other apart.
The general concern about multi-sowing is that we’ll get small-sized plants: 4-5 small roots instead of a large one, but that’s not always the case. Check out this article on multi-sowing beetroot to see the ridiculous size of beets I’ve grown this way.
Actually, I’ve learned that, when sown in clumps, you can harvest the roots and bulbs successively, as one root or bulb will develop sooner than the others. Simply twist it out, careful as not to dislodge the other roots, and the remaining plants will continue to grow.
One note on leeks: I’ve noticed that when sowing them in clumps of 5 or more, they were indeed producing smaller-sized leeks, but plenty of them. I like them better because they’re more tender.
But if you’re looking to grow big leeks, multi-sowing isn’t for you.
PROS and CONS of multi sowing
Multi sowing is very simple, and you shouldn’t be afraid to give it a try. But if you’re not yet convinced, here are the pros and cons of this method:
Multi sowing PROS
- You have absolute control over how many plants to have in one cell, by selective thinning. You can get rid of the weakest seedlings.
- You have control over where exactly to plant your clumps, as well as the spacing between them.
- This, in turn, means better use of space.
- You will work less on thinning, and there will be fewer weeds because your densely sown plants will shade each other.
- Some plants like companionship.
- You can harvest in succession by choosing the bigger roots or bulbs and leaving the smaller ones to grow.
- Plants don’t grow homogeneously inside the clump, they have a staggered growth (but that can be a pro as well, depending on how you see it)
- You will need a warm, bright place to start your seeds, like a greenhouse or grow lights.
- You will need seedling trays and bottom flat trays to keep the water in.
- Many plants aren’t suitable for the multi-sowing method.
How to sow seeds with the multi sowing method
We’ve been talking about how to sow your seeds inside module trays using the multi sowing technique and you’re now probably wondering: what is the best tray size for this method.
I found that a 72-cell module tray that is 21.25 inches long, 11 inches wide, and 2.25 inches deep, is both the most generous yet economical size for starting most seeds, including multi-sowing.
If the soil mixture is right, and you stay on top of watering, you should be fine.
If, however, you choose to go with a smaller tray, bear in mind that there will be multiple seedlings in one very small cell, growing a lot of roots and occupying that space very quickly.
If you transplant these seedlings too soon, they’ll fall apart, while if you leave them in for too long, they’ll eat up all the nutrients inside the cell. You can also go wrong by overwatering or underwatering in cells that are too small.
When your multi-sown seedlings are about 4 weeks old, harden them off and transplant them as you would any other seedling. Don’t be afraid to plant them deeply, even bury their stems a little bit – this will make for sturdier plants.
Can you multi sow carrots?
You should sow carrots directly in the ground, that’s their preferred method, as transplanting them will hurt their roots and you will get forked or distorted carrots.
When carrots grow about 4 inches tall, you should thin them to ensure better root development. If you don’t do this, you’ll still get carrots, but they will most likely resemble baby carrots.
You shouldn’t multi-sow carrots for these two reasons alone: they hate being transplanted and they need room to develop – their roots won’t push each other apart.
What about multi-sowing bigger plants?
While no one would imagine multi-sowing tomatoes or peppers, there are some plants that are initially sown in small clumps, and then thinned out until only the strongest seedling remains.
This process is called station sowing, and it consists of making holes in the ground, instead of drills. This method serves plants that have very large seeds such as corn, squash, zucchini, cucumber, peas, and beans.
It’s very different than multi-sowing because station sowing is a method that is meant to ensure germination and leave the strongest seedling, whereas multi-sowing aims for a bigger harvest from the same space.
You shouldn’t attempt to plant large plants too close together or in clumps, it will most definitely stunt their growth.
However, I’ve tested planting pepper seedlings in pairs, and it’s been a great success. It was a tip an old gardener gave me, but I still need to investigate why this works so well.
I hope I’ve convinced you to give multi-sowing a try. Here’s a summary of everything you’ve learned:
- Crops like beetroot, radish, onion, turnip, and leek will push each other apart while growing, and they will grow to a normal size;
- The crops above will have a staggered growth – pick them as they mature;
- When harvesting one root or bulb at a time, carefully twist them out;
- You can sow between 4 to 8 seeds inside a cell, depending on your plant;
- When transplanting them, space them as you would with just one plant, or maybe a little more;
- The ideal tray size is 72 cells, 21.25 x 11 x 2.25 inches;
- Don’t confuse multi-sowing with station sowing;
- Bigger plants that need space can’t be multi-sown.
Gardening in a small space is all about efficiency: working less and harvesting more. Multi-sowing is the perfect way to do that, and it’s proven to work. You can triple or even quadruple the number of plants you harvest in this way and enjoy them at a medium size.