Polyculture is when you mix plants up rather than sowing them in huge patches. It can help avoid pest problems by breaking up the smells of plants and making them harder for insects and pests to find.

It is the opposite of monoculture which is the planting of one crop in a space.

Polyculture includes multi-cropping, intercropping, companion planting, and beneficial weeds.

Multi-cropping means having two crops from the space in one season – often radishes can be uses as part of a multicrop system as they grow quickly, but any quick growing crop can be used. They can be used to mark the line of a row of slower to germinate seeds. This harvesting in relay can be useful for getting more food from a small space. The three sisters planting – corn, beans and squash is an example of this.

Inter-cropping is when one crop is grow between the space between another. Some people use garlic – a tall growing plant – to fill in gaps. The garlic never takes much space and so is happy dotted about in gaps. Intercropping can be used with smaller spacing as some of the crop will be removed before taking too much room, allowing the remaining crop more space to grow.

Companion planting – example is when a combination of tomatoes and marigold can be multi-cropped to help deter some tomato pests.

Use of beneficial weeds – can be seen as a green manure waiting to be hoed into the soil. If you remember to hoe before they seed then this is fine. Some weeds can protect plants by keeping away pests either by smell or physically making it hard to get to. Nettles allow early aphids which in turn benefits ladybirds making it a good plan to allow a corner of your space to have some in.

Issues which might occur include not identifying the crops as seedlings if they’re not in rows. More experienced gardeners shouldn’t have this problem.
Some plants may be too vigorous for sharing space with other plants and cause issues over light, air, watering and feed requirements.