Plant This Companion Flower By Your Peonies To Help Them Truly Flourish

For many gardeners, growing peonies (​Paeonia​ spp.) is one of the best ways to create a gorgeous landscape without needing to do a ton of work. Not only are they ridiculously easy flowers to grow once you get them settled in, but those giant bursts of blooms come back every year and look oh-so dramatic. Companion planting around giant peony bushes can be difficult, however, as few plants are able to handle being around such big shrubs. Luckily, the hardy geranium (Geranium spp.) is happy to be your peony's next-door neighbor.

Hardy geraniums make fantastic underplantings around bushes, trees, or shrubs, as they can handle the partial shade created by the bigger plant's canopy. Plus, they like the same growing conditions as peonies, and they come in so many colors that you can create plenty of different landscape designs with them. Should they match your peony's blooms for a consistent color scheme, or contrast them to make your garden more dynamic? The options go as far as your imagination. To begin, though, you need to understand which type of geranium will do best next to your peonies.

To be transparent, some sources believe that there's not much scientific proof that companion planting is as helpful as it's made out to be. That said, hardy geraniums bring a lot of benefits to peonies that are hard to ignore. For one, they're, well, hardy, and have exceptional disease and pest resistance, so putting them next to a peony won't make your shrub more likely to contract the more common diseases peonies get, like powdery mildew or blight.

Since they're also low growers, hardy geraniums make excellent weed suppressors since they block the light and water that weeds would need to flourish. This can come as a relief to your peony, especially in its early growth stages, when it needs as many resources as possible, and competing with weeds might stress the plant to the point of smaller or no blooms. But maybe you're wondering if the geraniums would compete with your peony. The answer is: not likely. Hardy geraniums aren't heavy feeders, so they require little nutrients, and if you plan the bloom times just right, peony and hardy geraniums' growth periods will pass each other by, ensuring every plant gets what it needs when it needs it.

So, first, let's be clear that the "hardy" in hardy geraniums isn't just a descriptor  — it's actually a specific type of geranium. These plants are best grown in USDA zones 4 to 9. There are around 300 species out there, and they run the gamut in terms of height, color, and bloom periods, so you're sure to find at least one type that fits your garden and growing conditions. The trick is to study your peonies first so that you can choose a companion plant accordingly.

As we've mentioned, you can pick your hardy geranium companion based on bloom color to either complement or contrast your peonies. The next thing to consider is timing. Different types of peonies will bloom at different times, so you may want to grow a hardy geranium variety that will bloom when your peonies are dormant; this means that they won't compete for resources, and it'll help keep your garden packed with color. 

You should also consider the height of the plants. Larger hardy geranium varieties can reach similar heights to peonies, which grow up to 3 feet tall. Others, however, are much shorter. As such, your geraniums may need to be planted with a little space between them and your peonies. This will prevent the peonies' canopies from completely shading them out of the sunlight that they need to thrive. If your geraniums start to get a little leggy, that's a sign they're getting overshadowed — literally — by your peonies, in which case they'll need a little more room.