Water, soil and containers
Practise first, or open the explanations as you go. A useful gardening answer includes the conditions in which it applies.
Water wisely
What should come before watering a pot?
Checking the compost moisture
Water according to the plant and its growing medium, not a fixed calendar rule.
What is waterlogging?
Growing medium staying excessively saturated
Excess water reduces the air available to roots.
Which part normally needs the water most directly?
The root zone
Aim water at the growing medium where the roots can use it.
What can drainage holes help excess water do?
Leave a container
Drainage holes let surplus water escape; they must not be blocked.
Which statement is safest?
Water needs change with conditions
Weather, plant size, growing medium and root condition all affect watering decisions.
Further reading: RHS guidance. Questions and explanations are original; no RHS endorsement is implied.
Compost and soil
What is a growing medium?
The material roots grow in
Soil and potting compost are examples of growing media.
Is garden compost the same thing as every bag of potting compost?
No
Garden compost is decomposed organic material; potting composts are formulated growing media.
What does organic matter help improve in soil?
Soil structure
Appropriate organic matter can help improve soil structure and moisture behaviour.
What should guide the choice of potting medium?
The needs of the plant and growth stage
Seedlings and established plants can have different growing-medium needs.
Why avoid walking on a prepared growing bed?
To reduce compaction
Foot traffic can compact the soil and reduce useful pore space.
Further reading: RHS guidance. Questions and explanations are original; no RHS endorsement is implied.
Making compost
Which material is a useful compost ingredient?
Suitable uncooked plant trimmings
Plant material can decompose; remove non-compostable packaging and hardware.
What is decomposition?
Organic material breaking down
Organisms break organic material down during composting.
Why mix soft green material with drier brown material?
To help make a balanced compost mix
A suitable mix helps the composting process and texture.
Which item should stay out of ordinary garden compost?
Plastic twine
Plastic does not turn into useful garden compost.
What can turning compost help introduce?
Air
Aeration can help composting organisms work when the heap needs it.
Further reading: RHS guidance. Questions and explanations are original; no RHS endorsement is implied.
Mulching
What is a mulch?
Material spread over the soil surface
Mulches cover the soil surface for purposes such as moisture conservation and weed suppression.
Which is an organic mulch material?
Composted bark
Composted bark is one of several organic mulch materials.
Can mulch completely remove the need to check moisture?
No
Mulch can conserve moisture but is no substitute for checking conditions.
Where should mulch generally not be piled tightly?
Against plant stems and trunks
Keep stems and trunks clear to reduce problems from prolonged damp contact.
What is one common purpose of mulching?
Suppressing some weed growth
A mulch can limit weed emergence while helping the soil retain moisture.
Further reading: RHS guidance. Questions and explanations are original; no RHS endorsement is implied.
Potting and spacing
What does potting on mean?
Moving a plant into a larger container
Potting on gives an established plant more root space when appropriate.
Why avoid a sealed container with no drainage for ordinary pot plants?
Excess water cannot escape easily
Most ordinary container plants need drainage to avoid prolonged saturation.
What is a root ball?
The mass of roots and attached growing medium
Keep the root ball appropriately supported when moving a plant.
Why leave suitable space between plants?
To allow growth and access to light and air
Crowding can make plants compete and make care harder.
What should determine whether a plant needs repotting?
Its root growth and condition
Assess the plant rather than repotting every species on the same schedule.
Further reading: RHS guidance. Questions and explanations are original; no RHS endorsement is implied.