I planted some peonies a couple of years ago. They are blooming for the first time this year, but the flower buds have ants all over them. What should I do? LT

Peonies are a long-time garden favorite and a perennial in every sense of the word. Cold in the winter actually helps peonies because they need a good winter chill to break dormancy and grow. To accomplish this, temperatures must be below 40 degrees, but peonies are hardy to minus 50 degrees making them a lot tougher than the plants so many of us lost during the great deep-freeze a while back.

Peonies are native to Asia, Europe, and Western North America. They have been grown and cultivated in Asia for more that 2000 years. These cultivated varieties were brought to the United States around 1800. Not only are they beautiful, but peonies can continue growing and flowering for more than 50 years, some for even 100 years or more.

You should expect peonies to bloom from late spring to early summer. Traditionally peonies were white, pink, or red, but now due to creative breeding, peonies can be found in coral, yellow, and several patterned varieties. Peonies can grow 2 to 3 feet tall with potentially a 3 to 4 foot spread when mature making them a wonderful plant for your garden.

When planting peonies you need well-drained, loamy soil for best results. Good drainage is also essential since it will help you minimize root rot and fungal disease issues. If you have soil with a high clay content, you should amend it with compost or other organic matter to improve drainage.

You mentioned that your peonies did not bloom for the first couple of years. This is typical since it can take 2-3 years for peonies to get established before blooming. For those whose peonies still aren’t blooming after 2 or 3 years, it’s likely your plants aren’t getting enough sun. Peonies prefer full sun but can tolerate a little shade. If they are not in a place that provides them with full sun, it’s time to move your peonies to a better location but be prepared to wait a couple of years for blooms while your peony gets established in this new location.

Another potential issue for peonies that are not blooming could be that they are planted too deep. For your peony to thrive, the crown of the plant shouldn’t be planted more than two inches below the surface. If planted below this level, you will get great foliage but few blooms.

Over-fertilizing can also reduce the blooms on peonies. Too much nitrogen can cause the plants to grow a robust crop of foliage but will reduce the number of blooms. Established peony plants only need to be fertilized every few years and then only fertilize after they are done blooming.

Peonies don’t have a lot of disease or insect issues, but powdery mildew can be a problem. Powdery mildew is a fungal disease that thrives in plants that don’t get a lot of air circulation. You will probably first notice powdery mildew on your plant as small, individual whitish spots, but these spots expand rapidly to make the entire plant look like it was dusted with flour or a similar substance.

As a first line of defense, plant your peonies in a place that allows for a lot of air circulation, in other words, don’t crowd them. If you do start to notice indicators that powdery mildew is developing, begin treatment with a fungicide such as copper fungicide following the directions on the label. In the fall, you can cut back the dead stems down to the ground and dispose of them. Doing this will help minimize any carry-over disease problems for next year.

Now let’s talk about ants on peonies. As the buds on peonies begin to develop in the spring, flower buds can become home for a sometimes-unnerving quantity of ants. The question is: are these ants hurting or helping?

The reality is that peony buds have something called extrafloral nectaries on the leaf-like structures that surround the flower before it opens. The nectaries excrete nectar prior to the flower blooming. This external nectar source attracts ants. When an ant locates nectar on a peony, it emits an odor or pheromone trail on the way back to it’s nest. There, the other ants are alerted and then follow the trail back to the peony to feed on some delicious nectar.

Secondarily it is believed that the presence of ants on peonies helps to deter other perhaps less beneficial insects such as thrips. But that is where the relationship between ants and peonies ends; the ants are not necessary for peonies to bloom.

So, there’s no reason to fear or try to eliminate the ants on your peony buds. They aren’t hurting and may actually be helping. See you in the garden!

You can get answers to all your gardening questions by calling the Tulsa Master Gardeners Help Line at 918-746-3701, dropping by our Diagnostic Center at 4116 E. 15th Street, or by emailing us at mg@tulsamastergardeners.org.

Photo courtesy Tom Ingram