Using Grow Bags

Method

Grow bags are a simple way to raise crops where there is no border soil. They are especially useful in a greenhouse or on a sunny patio, giving tomatoes, peppers and courgettes a ready-made root run. Their main challenge is keeping compost evenly moist through warm, bright weather.

How to do it

Place a grow bag on a level surface with good drainage before opening it. Shake the compost into an even layer, make the planting holes specified on the bag and create extra drainage holes underneath if necessary. Plant crops at the recommended spacing, firming gently around the roots. Insert canes, a frame or strings at planting time so supports do not disturb roots later. Water slowly at each plant until moisture reaches the lower compost, then check daily in summer. Feed fruiting crops as directed on the fertiliser label once they are established. Remove yellowing leaves and harvest regularly to maintain airflow and productivity.

Best plants

Classic grow-bag crops are cordon or bush tomatoes, sweet peppers, chillies and compact cucumbers in a warm greenhouse or sheltered patio. Compact courgettes can use a grow bag if given enough space and reliable water. Basil makes a useful companion in a spare corner. Avoid overcrowding with too many large plants, as each needs a substantial share of compost and moisture.

Tips

Grow bags dry faster than large tubs, particularly beside a warm wall or greenhouse glass. Water in the morning where possible, applying it slowly so it soaks in rather than runs away. Raise the bag slightly for drainage and keep its surface mulched. A reservoir planter or drip system can make holiday watering more manageable.

Using Grow Bags: frequently asked questions

How do I get started with using grow bags?

Place a grow bag on a level surface with good drainage before opening it.

What are the best plants for using grow bags?

Classic grow-bag crops are cordon or bush tomatoes, sweet peppers, chillies and compact cucumbers in a warm greenhouse or sheltered patio.

What are some tips for using grow bags?

Grow bags dry faster than large tubs, particularly beside a warm wall or greenhouse glass.

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General guidance for UK gardeners. Match plant choices to your light and shelter. Page updated 19 Sep 2026.