Peonies are a popular plant in gardens because they are so beautiful and are often considered the star of spring. They are fragrant, easy to grow, and come in a variety of colors, shapes, and sizes that make them perfect for any type of garden. Peonies also have a long history in China, and it is believed that the flower brings good luck.
When Peonies don’t bloom there can be a number of reasons for their failure to produce flowers. We are going to categorize the causes into when buds don’t appear and when buds appear and don’t open.
When Buds Don’t Appear
Plant Is Not Getting Enough Sun – Peonies need at least 4-6 hours of direct sun to bloom. This enables the plant to store enough energy for beautiful blooms.
Your Peony Is Not Supposed To Bloom – With there being so many different peony cultivators, you need to make sure you know the proper bloom time. Many bloom, in late spring but others bloom in mid-summer. Also, the climate you grow your peony in has an effect on bloom time too.
Newly Divided Or Transplanted Your Peony – If you just divided or moved your peony in the late summer it is typical, they do not bloom well the following spring. It might even take 2 to 3 years for the plant to re-establish itself.
Peony Is Planted Too Deeply – If you are planting a new peony or a root division make sure you do not plant it too deep. The tiny shoots or eyes of the peony tuber need to be about one to two inches below the soil surface. If you happen to do this you will grow beautiful foliage, but very few flowers.
Your Peony Is Too Young – If your plant is too old it might not bloom but if it is too young this can occur too. It can take up to 3 years for a plant to mature and even longer if you grow your peony from seed. If your plant is newly planted, it will take time for the plant to get used to its location. Plants grown from seed can take 4 to 5 years before they bloom.
Too Much Fertilizer – If the peony receives excess amounts of nitrogen, the plant will rarely flower regardless of your ideal growing conditions. Nitrogen promotes the growth of foliage at the expense of flowers. Use a balanced formula (10-10-10) or one low in nitrogen (5-10-10) in early spring before the new growth occurs.
Pruned To Much Or Too Early – Once the peony has stopped flowering, the plant is still working hard to produce next year’s bloom. This occurs under the surface of the soil. If this process is disrupted by pruning too much or too early, this can have an adverse effect next year.
When You Have Buds But They Don’t Open
Late Seasonal Freeze – This is often the cause of having buds but no flowers. If you get a late freeze in the winter or early spring it may damage the flower buds causing them not to bloom. It is worse when you get some early warm weather and then the freeze. The plant is tricked into it thinking it is time to bloom. This is referred to as “bud blast.” It is really regrettable when this happens.
Fungal Diseases – The most common fungi that attack flower buds, when the conditions are wet and cool is Botrytis blight, also known as gray mold. With this, you will see dark splotches on the stem and leaves, and the plant will look wilted. The bud will turn brown and shrivel. While there are sprays to help with this the blight spreads rapidly and is difficult to catch. The best solution is to clean the diseased foliage and buds and wait for the following year. Try to improve the air circulation around the plant and keep the foliage dry when watering the plant.
Pests – While this is rare, thrips or other insect pests can damage the flower bud and will reduce flowering. Insecticides do not usually work as the damage has been done early in the season.
Malnourished – This is another cause that does not happen that often but if your plant is not growing well (the plant is off-color, yellow, weak, or spindly), it is not strong enough to bloom, but it has buds. The solution is to move the plant to a better location and fertilize it lightly after the plant is established.
Can’t Compete With Plants Nearby – While peonies are not territorial and don’t spread aggressively but they do need their space. If they are near other shrubs or trees, they could have problems because they can’t compete with a tree’s root system. This will create dry conditions and compacted soil, causing poor or no blooming.
Hopefully, these reasons will help you out if you find you are having problems with your peonies!