Dip-treated trellis has a surface coating of preservative applied by immersion. It offers good protection but will need retreating every year or two to maintain it. Pressure-treated trellis has the preservative forced deep into the timber fibres under pressure, giving it far greater resistance to rot and insect attack over the long term. Pressure treatment is the better choice if you want a lower-maintenance option that holds up well through wet winters.
Garden Trellis Panels for Climbing Plants, Privacy and Screening
Trellis panels do more than just support climbing plants. MacBlair stocks a range of pressure-treated timber trellis to suit gardens of all sizes, whether the goal is screening, adding height to an existing boundary, or simply bringing structure to a bare wall or fence. The timber is treated to resist rot, insect attack and the kind of sustained wet weather Northern Ireland regularly delivers.
The range covers the most popular styles and sizes, including:
- Square lattice trellis panels, clean-lined and suited to both modern and traditional gardens
- Diamond lattice panels, a classic choice for plant support and decorative screening
- Fence topper trellis, which adds height above existing fence panels without replacing the whole run
- Expanding trellis sections, useful for smaller spaces or curved installations
Trellis topper panels are a practical solution where a boundary needs extra height. Fixing them to the top of fence posts keeps the light coming through while gaining useful privacy. The open lattice structure also lets wind pass rather than resist, which reduces load on posts and fixings over time. Note that combined fence and trellis height must not exceed 2 metres without planning permission in most residential situations.
For plant support, the gap size of the trellis matters. Smaller holes suit finer climbers like jasmine and clematis, while larger square openings work better for training roses or fruiting plants. Once plants are established, trellis also acts as a natural privacy screen. Pair trellis with wood preservative treatment to extend its service life, or use fence paint to match it to the rest of the garden scheme.
Trellis FAQ's
Yes, fence topper trellis panels are made specifically for this purpose. They fix to the tops of your existing fence posts to add extra height above the fence panels. The key thing to check is the total combined height once the trellis is fitted. In most residential situations in Northern Ireland, a boundary fence or wall must not exceed 2 metres in height without planning permission. If the finished height would go above that, you would need to apply to your local council before proceeding.
Climbing plants are the obvious choice. Clematis, honeysuckle, jasmine and roses are all popular options and respond well to trellis support. For smaller-gapped square or diamond trellis, finer-stemmed climbers like clematis and jasmine work best. Roses and fruiting plants such as trained apple or pear benefit from larger-gapped panels that give stems room to be tied in. Ivy is effective for fast, dense coverage but can become heavy once fully established, so make sure the trellis and its fixings are secure.
For a wall, use masonry wall plugs and screws at the top and bottom of the trellis frame. It is worth leaving a small gap of around 2–3cm between the trellis and the wall surface, as this allows air to circulate behind the panel and helps plants get their stems around the structure. For attaching to an existing fence, screw through the trellis frame directly into the fence posts rather than the fence panels themselves. This gives a much more secure fixing than attaching to the panel boards.
Pressure-treated trellis panels generally do not need immediate additional treatment, but applying a wood preservative or fence paint after installation will extend their life and keep them looking good. Dip-treated panels benefit from an annual coat of preservative to maintain protection, especially in wet climates. You can also paint or stain trellis to match the rest of your fencing or garden scheme. Use a product suited to exterior timber and make sure the surface is clean and dry before applying.