Can you plant Photinia red robin under gum trees?

[s321]

I'm wanting to plant a hedge along this fenceline to block out the road. I've engaged a landscaper who has recommended and quoted on planting 1.5m tall photinia trees along the fenceline with 800mm spacing.

I've seen lots of other houses around my area with photinia hedges so it's definitely suited to the area, but my concern is that I have tall gum trees that partially shade the fenceline. I can't cut down or even really prune the trees so they will always be there.

I understand that photinia prefers full sun and that I'm not going to get optimal growth by planting them here, but will they still grow and form a decent hedge? The landscaper is charging a lot of money (it's a long fenceline) so I'd hate to spend that much and have them struggle or even die altogether.

[JacobZ]

Hi @s321,

A warm welcome to the Bunnings Workshop community it is fantastic to have you with us.

While Photinia's do prefer full sun, they should still grow if they are in partial shade. As long as they are getting a minimum of about 4 hours of sun a day, they should grow, although it would take longer for them to fill in than if they got more sun. 

Aftercare is what will decide your photinia's success. I'd suggest laying a 100mm blanket of mulch, keeping a 50mm gap around stems to prevent rot. This will help to conserve moisture and regulate soil temperature.

Ensuring they are getting enough water is also essential. Deep watering at least once a week during the hotter months will ensure they are getting plenty of water. 

I'd also suggest feeding with a slow-release, balanced fertiliser like this Scotts Osmocote All Purpose Controlled Release Fertiliser in early spring to ensure they are receiving the nutrients they need to thrive in the warmer growing months.

Once plants are established and growing, start light, regular tip-pruning every 4–6 weeks in the warm seasons to encourage branching, which will help to fill in bare areas and create the screening effect you are after.

Overall, Photinia will grow there and make a decent hedge if you invest some time and maintenance into them; just budget for slower progress and slightly looser density than a full-sun planting.

Check out How to Grow, Prune And Propagate Photinia for some further guidance.

Jacob