I have a 5×7 garden with afternoon sun so it gets quite hot at times. will rhododendrons do well there?
Rhododendrons actually do better with morning sun and afternoon (light)shade, but they are pretty hardy plants and will probably do fine as long as its not too windy. If you are mulching with wood chips, you may need to add some fertilizer so it doesn’t get a nitrogen deficiency. Since they like acidic soil, it would be best to mulch with pine needles. So if there is a pine tree around, grab some of those needles for your plants. They will love it. If you want to plant other shrubs with the rhododendrons, take a look at the link below. They give several other acid loving shrubs that grow really well with rhododendrons.
There’s a lot of determining factors. If you live on the coast or somplace like Seattle, Rhododendrons will do very well in a sunny situation. If however you live somewhere like inland California you’ll probably either lose the plant or it will spend years trying to establish itself. There are azaleas that are more sun tolerant and look similar to the rhododendron such as the exbury hybrids. Also consider another flowering shrub for the area. Sweet pea shrub(polygala) is a great looking plant.
