What's the optimum spacings for veggies in containers?
How far apart do you need to space seeds and plants in a container? Do you follow the guidelines on the side of the seed packet – or can veg in containers be grown closer together? This is something I've tried to work out over the years. After playing around with different spacings, I've come up with some general rules of thumb that I hope you will find helpful. After playing around with different spacings, I 'discovered' some general rules of thumb. The spacings depend on whether you are sowing leaf, root, or fruiting vegetables - and what size of veg you want to grow - as summarised in the table below:-
Most leafy crops - salad leaves, kale and chard - and a few leafy herbs like coriander, can be sown nearly touching for microgreens (harvested very small), or a bit further apart for baby leaves (as small plants with true leaves). For full sized leaves, the seeds need to be sown at the distance recommended on the seed pack, or close to it. Alternatively, it's possible to sow close and then 'thin out' (remove) some of the seedlings. This gives the remaining plants the space they need to grow to full size. And the 'thinnings' are usually tender and tasty! Some root crops - like beetroot, turnip, spring onions / scallions - can also be sown nearly touching for microgreens (many root crops can be eaten as microgreens but not all - check first!), or a bit further apart (say 3cm / 1 inch between seeds) for baby roots. As with leafy veg, they need approximately seed packet spacings to grow full sized roots. One strategy that can work well is to sow for baby roots, then to thin to let the remainder grow larger. Most fruiting veg on the other hand need plenty of space. This is because a squash plant, for example, needs to grow to almost full size before it can fruit. For this reason, it's best to sow fruiting veg at, or close to, the spacings recommended on the seed packet.
What's the best spacing option?
There isn't a right or wrong here. But I hope you'll find it useful to know that - with the exception of fruiting veg - most leafy and root veg can be sown either close for smaller plants or further apart for larger ones. Try different spacings to find which you like best. Quite often, I prefer to sow leafy and root veg quite close (1 - 2 cm apart), then thin them out as they grow. This is because:
- If slugs or blackbirds eat some seedlings or dig them up, there are usually a few left over!
- I get an early and extra harvest when I thin out the seedlings - most baby leaves are very tasty.
- Or I can move the extra seedlings into other pots where there is space. For example I will move some of the spinach seedlings (photo below) into another pot I've just emptied of French beans. These will be three weeks further ahead than if I sowed spinach seeds into the same empty pot.
Sowing seeds close together does require more seeds. However, seed packs (particularly for leaf and root veg) often contain many more seeds than we actually need for a small container garden. So it's one way to make good use of the extra.
Exceptions to the General Rules
These general rules can help you to work out how far apart to sow different seeds but, as with most rules of thumb, there are a few exceptions, most notably:
- Potatoes or anything else grown from a tuber. In general these need plenty of space, there is no benefit of cramming them into a container. For example, I normally only plant one potato tuber or one Jerusalem artichoke tuber in a bucket sized container.
- Climbing beans and peas. Unlike tomatoes and squash, climbing peas and beans seem to grow well closer together. I generally grow at least 12 climbing beans in a 50 litre container and up to 18 peas. It may be possible to cram even more into a pot, it would be interesting to try. (If you have, I’d love to hear in the comments). Dwarf peas and beans, on the other hand, are bushier and quickly overcrowd a pot if grown close together.
- Most perennial herbs. Some annual herbs like coriander and basil will grow well if sown close together (thinning out if desired). But most perennial herbs like thyme, bay, and mint need more space.
When is it better to start seeds in smaller containers?
Of course, there are times when sowing seeds in the final container isn’t always the best strategy. For example, it's best to start fruiting veg like tomatoes, chillies and squash inside in small pots. Then move them outside into their final container. And sowing seed trays or modules of leafy veg will give you seedlings to move straight into pots as soon as they become empty. This can be a great strategy for growing more in a small space. On the other hand, sowing leafy and root veg quite close in their final container does save the time of sowing them in small pots or trays first.
What’s your experience?
How do you space your veg in containers? Do you use seed packet spacings or have you developed your own method? Have you noticed if you get better results from close spacings or more further apart? Are there any veg you've had particular success with by growing them close together? Or any other thoughts on spacing? I'd love to learn from your experience in the comments below.