RAISED BED LINER FREQUENTLY ASKED QUESTIONS
1. Are weeds suppressed?
If the bed is positioned over ground with persistent weeds they may push through so we recommend using a liner to help prevent this and weeding beforehand.
Weeds are suppressed more when growing in raised beds as the crops can be planted closer together due to the fertile well aerated soil. This is more likely to starve the weeds of light and nutrients.
Also the lighter, un-trampled condition of the soil makes weeding a doddle.
2. Do raised beds require more watering?
It very much depends on what you are comparing them to and what substrate they are sitting on.
If you have very sandy soil in your garden and you switch to raised bed gardening, you can select a soil for the raised beds that is better at retaining water, coupled with a liner this will help reduce water loss.
Raised beds will warm up faster than a traditional bed so you do need to keep an eye on how dry the soil is.
If the soil under the bed is heavy clay and water logged, obviously drainage may be a problem. A few inches of gravel in the base of the bed will help in this situation.
3. How much soil do I need to fill my bed?
Multiply the depth cm x width cm x length cm = (result) ÷1000 = amount in Litres
e.g. for a 4ft x4ft x 1 tier bed: 120cm x 120cm x 15cm = (216,000) ÷ 1000 = 216 Litres
1000 Litres = 1m3 = 35.3 ft³
4. Do you need to put anything in the raised bed to help with drainage?
This depends on where the raised bed will be situated in the garden. If the raised bed is being placed directly onto soil the drainage should not be a problem because the excess water will drain through the grass/soil underneath it.
If the soil is heavy clay and water logged obviously drainage may still be a problem. A few inches of gravel in the base of the bed will help in this situation.
On free draining soil a liner may help conserve water as it will prevent the water draining too fast. consider the type of soil/compost that you are going to fill the bed with and tailor it to suit the site.
If the raised bed is being placed onto a patio, we recommend lining the inside of the bed, this will help retain water and also prevent fine sand from washing out of the bed onto the patio.