How do I stop birds and cats damaging my garden?

Physical barriers and deterrents that work, applied humanely, plus the ones that reliably do nothing.

Difficulty: beginner
Time: 45 min
Read: 2 min

Short answer

Physical barriers are the only thing that reliably works — netting over seedlings, twigs or prickly cuttings pushed into bare soil, and mesh over newly sown beds. Sonic and visual deterrents work briefly and then get ignored.

Both problems are about bare soil and new growth: cats dig where there is loose earth, birds eat seedlings and fruit. Anything that physically prevents access works; anything that relies on frightening them works only until they learn it is harmless.

What you'll need

Netting or mesh
Prunings or twigs (optional)
Canes (optional)

Step by step

Cover newly sown or planted beds with netting or mesh.Supported on canes so it does not touch the plants. This is the only fully reliable answer for seedlings.
Fill bare soil so cats cannot dig.Push prunings, twiggy cuttings or short canes into the surface. Cats want loose, open earth and will go elsewhere.
Mulch bare soil with something coarse.Bark chips, pine cones or gravel are all unpleasant to dig in. It also helps the soil, so nothing is wasted.
Net fruit properly, with the right mesh size.Fine enough to exclude birds but installed so nothing can get trapped inside. Check it daily — this matters.
Use bird-safe deterrents around fruit.Reflective tape and old discs work for a while. Move them regularly, since birds habituate within days.
Give birds an alternative water source.Much of the damage to soft fruit is birds seeking water in dry weather. A bird bath genuinely reduces it.
Water where cats are using the soil.Cats avoid wet ground and strongly scented plants. Damp soil plus a scented barrier planting is quite effective.
Protect the specific plants, not the whole garden.Trying to exclude wildlife from a whole garden fails. Protecting seedlings and fruit for a few weeks succeeds.

Tips

Birds also eat enormous numbers of aphids, caterpillars and slugs. Excluding them entirely trades one problem for several.
Check netting daily for trapped birds or hedgehogs, and use taut netting rather than loose drapes — loose netting is where entanglement happens.
Cats return to the same spot from habit. Interrupting them for two weeks usually breaks it permanently.

Common mistakes

Relying on sonic or visual scarers alone — Both birds and cats habituate within days once nothing bad happens. Physical barriers do not wear off.
Using loose netting — Birds and hedgehogs get tangled in slack netting. Taut, well-supported mesh avoids it.
Leaving fine soil uncovered after sowing — It is exactly what cats look for. Covering it immediately prevents the problem entirely.

Questions people ask

How do I stop cats using my garden as a toilet?

Remove the appeal — cover bare soil with coarse mulch, push twigs into the surface, and keep it damp. Cats want loose dry earth and will find it elsewhere.

How do I stop birds eating my seedlings?

Netting or mesh on canes over the bed, so it does not touch the plants. It is the only reliably effective method; scarers stop working within days.