Many acid-adapted plants we admire in magazines can’t thrive in our alkaline soils. Luckily, there are several stunning substitutes in drought-hardier packages!
We’re lucky to have a long growing season in San Antonio, but there are a few things to consider when you bring a new plant into your garden.
We often discuss watering requirements and soil type, but one topic that isn’t too well known is soil pH: The logarithmic measure of the relative abundance of hydrogen ions that determines a soil’s acidity or alkalinity.
Bexar County soils are mildly or moderately alkaline because we sit on limestone — meaning many of the acid-adapted plants we admire in garden magazines (and some home improvement stores) are unable to thrive for long in our soil. These include azaleas, rhododendrons, blueberries, gardenias and my personal favorite, hydrangeas (which actually change color based on soil pH).
These plants are all adapted to acidic soils, and that’s something we can’t reliably achieve in South-Central Texas. Sure, you can make soil amendments and use supplements around the root zone, but this is only a temporary measure that requires a lot of work. As their name suggests, hydrangeas must be watered frequently, and they don’t tolerate heat well. Our soil further compromises their ability to obtain the nutrients they need to thrive.
Plants accustomed to acidic soils often suffer from iron chlorosis locally because pH is linked to iron absorption. The higher the pH, the more alkaline the soil, and the harder it is for the plant to absorb iron. Iron is instrumental in producing chlorophyll, which chlorosis often manifests as a yellowing of the leaves.
When it comes to the home landscape, approach it like you’re giving a good friend some advice: Be yourself, don’t force it, don’t stay where you aren’t thriving.
Plants won’t bother to conceal their unhappiness with conditions where they can’t cope. So don’t feel down because your favorite plants won’t make it here. Instead, consider the many gorgeous native and well-adapted options that can fulfill the same roles or offer similar appearances. Plumbago is a lovely swap for hydrangea with a similar effect but in a drought-hardier package!
Our find a plant feature can you help find the perfect replacement — just sort by watering requirements, flower color, soil type, sun requirements and many more characteristics.
