Oftentimes, when folks think about planting a bougainvillea or other drought-tolerant plants in their garden, they figure that all they have to do is pop the thing in the ground, water it, and, voilà, they have an instantly sustainable landscape plant that can immediately fend for itself. Not so, amigos.
Bougainvilleas have fragile roots and, apart from requiring extra care and diligence when planting one, getting it established in your garden and teaching it to be self-sufficient can often be a complicated case.
Initially they have to be kept evenly moist and not allowed to dry out, just like any other landscape plant. As the plant gets going, though, it should be encouraged to develop deep roots by watering thoroughly but less often. Their large and fibrous root systems will eventually go looking for a water source such as a nearby drip system, other irrigation areas in your garden, or even a leaky hose bib. It’s best to let the plant find its own water rather than irrigate it regularly with the rest of your garden.