A general rule is that slow growers need more space and fast-maturing vegetables need less. Many of the vegetables in this chapter are slower to grow and mature.
Vegetables at 35–37 cm
As spacings grow wider, growth happens more quickly to fill that space. Celeriac is an exception, though you can pop spring onion transplants between them as a catch crop (see the photo below).
Kaibroc (Brokali) and Chinese cabbage
Both of these make fantastic growth in the cooler conditions of autumn and they tolerate some frost, perhaps to –3°C / 27°F. They mature exceptionally fast and this influences spacing.
- Kaibroc needs less space than other broccoli types because it matures quickly – it can be spaced as close as 30 cm, rather than at 45 cm. On average, I favour 35 cm.
- Chinese cabbage needs more space for heading than, say, lettuce, so that it can pull more moisture and food from the larger area of a 35 cm spacing, compared to 30 cm for lettuce heads. Another advantage is more air between plants and less habitat for slugs, which can cause much damage to Chinese cabbage.
At Homeacres, both of these vegetables grow well from sowing in late July to early August. Chinese cabbage has time for a head to develop, of worthwhile size and at a time of year when fresh leaves are becoming scarce. Kaibroc may continue to give small broccoli even after first frosts.
Celeriac and swede
Strictly speaking, these are swollen stems, sitting between roots and leaves. They swell outwards as much as downwards, and a 35–37 cm spacing allows for growth of a decent-sized root.
It is possible to space them at 30 cm, even 25 cm for swedes. However, mostly one grows them for use through winter, when larger roots store better and are less fiddly to harvest in cold conditions.
Celeriac, in particular, grows a lot of leaf proportionate to root when spaced too close. 37 cm gives room to grow, without wasting space. After trimming all the small roots, each celeriac can weigh as much as 1 kg / 2.2 lb, giving a high yield per area used.
Large brassica plants and potatoes at 40–60 cm
Brassicas in this category include cabbages for large heads, most broccoli, cauliflower, Brussels sprouts and kale for large leaves.
Cabbage
For large heads in autumn, space cabbage as wide as 60 cm. Cabbage for smaller heads can be at 35–40 cm, or even 30 cm for early-heading spring cabbage.
Calabrese
Calabrese is fast-growing. Transplant in early April at 45 cm, for large heads of green broccoli from early summer to mid-autumn, followed by some regrowth of sideshoots for another month or so. Then twist them out and plant April-sown leeks or June-sown beetroot.
A second sowing in mid-June can be transplanted in early July, again at 45 cm. You can also plant at 40 cm, for slightly earlier harvests of smaller heads.
Cauliflower
Cauliflower leaves grow very long and these are space-hungry plants. 45 cm is the minimum spacing, while up to 60 cm gives larger curds.
Romanesco, the plant of fractal geometry, makes a nice head at a minimum spacing of 45 cm, of medium size, depending on variety. They have a more upright habit than many cauliflowers.
Potatoes
My suggested spacing is 45 cm for second early varieties, but you could go wider, up to 60 cm. For maincrop potatoes, 60 cm is a good spacing.
Second early potatoes have many virtues compared to maincrop:
- They do most of their growing before the possible arrival of blight, in midsummer.
- Their early cropping means there is time to grow another vegetable in that bed.
- They can make a decent harvest, with less space per plant, as they mature more rapidly.
- Many of them store almost as well as maincrop varieties.
Winter Brussels and spring broccoli
Overwintered broccoli needs both time and space, from which it rewards you with large and beautiful harvests in the hungry gap. The exact timing of harvests depends on both weather and which variety you grow – it’s vital to check the small print on each seed packet.
These plants survive to about –8 or –9°C / approximately 16°F. They don’t grow a lot in winter but make up for it in early spring.
Brussels sprouts give best results at spacings as wide as 60 cm. They need a few months to grow before they form buttons and, if they are cramped for space, the chances are they will run out of moisture and food, as well as light. This would result in a poor harvest of small buttons, probably also with diseased leaves.
Tomatoes, cucumbers and melons at 45–60 cm and more
Spacing varies according to the type of tomato and cucumber, such as bush or cordon, and whether you grow them outside or under cover. This is a brief overview, starting with the closest and going to the widest:
- Outdoor bush and cordon tomatoes, at 45–50 cm, have space for growth all summer, and the spacing is wide enough for you to find ripe fruit when picking bush tomatoes.
- Outdoor ridge cucumbers, at 60 cm, allow space for plants to trail in all directions, which they do very quickly in warm conditions.
- Under cover cordon tomatoes, at 50 x 80 cm, have space for access and ventilation (less risk of late blight), as well as growth continuing over five to six months.
- Under cover cucumbers, at 70 x 80 cm, give cucumbers of a decent size and quality over the whole season.
Melons and watermelons need wide spacing, preferably 60 cm. To save space, you can grow melons up a string, as with cucumber and tomato, and spaced at 50–60 cm.
Early Moonbeam is a good watermelon variety for cooler summers, and in 2019 one plant gave three watermelons of 4 kg / 9 lb each, in the greenhouse. They are easy to grow, provided you have enough warmth.
Widest spacings
All the cucurbit family need a lot of space, but only for the few months of high summer. Then, as autumn arrives, their old leaves become covered in powdery mildew, which is a normal sign of old age and nothing to worry about.
Winter squash and pumpkin
A spacing of 1 m works well for all squash, but they will take more room if you allow it. For example, Crown Prince are super vigorous and you can let them run, say, under fruit bushes, even over grass, as in the photos below. The stems are not there for long; by early autumn they start to die back, and you then have more harvest for little extra work.
A squash I recommend for eating in autumn and winter is Red or Uchiki Kuri, which you can space a little more closely than 1 m. It grows ripe fruit so readily that you can even harvest them in early autumn, clear the leaves and stems, and then plant spring onions, spinach or salads.
Pumpkins need more space to grow, for the really large ones, and they can be as much as 2 m apart. For a giant pumpkin, you could grow just one plant and give it as much space as you can. All cucurbits make new roots from their trailing stems, hence the ability of one plant to produce many fruits, or just one really large one.
- For a giant pumpkin only, prune off all other fruits.
- For squash harvests, leave the plants alone and allow them to self-prune. You don’t need to remove any fruits or trim any leaves, apart from keeping plants to the space you have allocated.
Downloadable PDF: Spacing Guide
