Space to Grow: Thinning and Spacing

I have just recently thinned my lettuce and spinach.

Plants need space to grow!

How much space they need depends on the size of the mature plant.

So when you are planting your plants it is important to take note of the recommended spacing which can usually be found on the plant label or on seed packets.

Seed packet spacing info

This will also give you an indication of the number of plants you can grow in your particular container.

Sometimes your desired end use can have an influence on spacing used. If for instance you want to harvest leaf lettuce rather than letting them fully mature and form hearts you can have your plants closer together. This is my preferred method of growing and harvesting lettuce. I like to just harvest the amount I wish to use and use it fresh rather than harvesting a whole mature lettuce and storing some of it in the refrigerator for later use.

I do the same for spinach. I grow them quite close together and just harvest them leaf by leaf according to what I need. You can harvest them over a long period of time in this manner.

When harvesting anything in this manner it is important to always harvest the outside leaves as the plant continues to grow from the center. If you remove the growing center it won’t keep on producing.

If you are starting off with transplants you will be planting at the desired spacing right away and eliminate the need to do the important thinning step required when you are starting from seed.

Some larger seeds you can place at the desired end spacing when you are sowing but with smaller, finer seeds this is pretty much impossible so you will have to thin the plants to the desired spacing at a later date.

This is important to do especially if you have been a bit heavy handed in your seed distribution at sowing or you have had a spectacular germination of the seeds you have sown. If your little seedlings have come up really close it is quite important to thin them quite early on so that they don’t all end up spindly and competing with each other. This is also the time to fill any gaps with the seedlings you are discarding.

You could do your thinning in more than one go. To begin with you could just give the seedlings space to breathe and grow and then at a later stage you could thin to the desired end spacing. You could do your final thinning as you harvest by removing the whole plant when it is at a usable stage; this works for lettuce and the like when you can use them at a young stage.

Thinning lettuce

It can also work for carrots where you can strategically harvest baby carrots and make room for the rest to grow bigger.

If your plants aren’t too thick at the start you could just thin out the whole plants as you start to harvest.


Thinned lettuce ready for use in salad


Thinning spinach at a usable size.


Sometimes it is very tempting to just let all the plants grow especially when they are looking so good when they are young. But I’m afraid you just have to be a bit ruthless and give the plants the space they need to reach maturity.

Growing too many plants in close proximity will give you disappointing results down the track. As the plants get bigger  and older they will compete against each other for precious water and nutrients, and remember when growing in containers there is only a limited amount to go around. If there are too many mouths to feed and not enough food for everyone they are going to starve or at best be very stunted unable to reach their potential. You won’t get the results you could have done if you had carried out this step.

You sort of have to be cruel to be kind; you have to sacrifice some plants in order for the others to survive and flourish!

You can find out more about thinning and spacing in “The Easy AZ Method”