Peonies are some of the most beautiful flowers to grow. But it can be frustrating when you’re doing all you can and the plants just won’t bloom. The problem is that peonies can be delicate and picky when growing.
Peonies won’t bloom because they are in too much shade and not getting the required 6 hours of full sunlight. They won’t bloom if you planted them too deeply or not providing them with the required watering.
I’ve shown you the most common reasons why your peonies are having trouble blooming. But there are several other situations you need to be aware of. I’ve written those down as well as the solutions you can use to fix this problem.
1. Lack of Sunlight
To reach its full potential, a peony plant needs at least 6 to 8 hours of sun every day. Full sun exposure is a must for peonies.
It’s possible to grow these plants in partial shade. However, the number of blossoms you’ll get to enjoy will reduce dramatically. Plants can also become leggy as they try to reach for more exposure.
In full shade, peonies are a complete wash. They will not grow without sunlight, so you need to make sure that these plants are getting the exposure they need.
If your peonies aren’t blooming, it may be encountering unexpected shade. Believe it or not, this is a common issue many gardeners face.
Many will put their plant in a seemingly ideal solution. Early in the growing season, your peonies could get full sunlight to produce buds. But, the continued growth of nearby trees or shrubs might end up casting some unexpected shadows.
Keep a close eye on your peonies throughout the day. Make note of the sun’s position and how nearby plants cast shadows. That nearby tree that was barren earlier in the season might be full of leaves that block out the sun in the afternoon.
Take some time to eliminate overhanging branches. You can also prune trees to ensure that the sun isn’t completely blocked. If push comes to shove, you can always transplant your peonies to a more suitable place in the garden.
2. Lack of Nutrients
Like any other plant, peonies can benefit from a little boost in nutrients. That said, peonies are a bit more finicky about fertilizers than most flowers.
You see, peonies have shallow roots. The root crown will only penetrate a few inches into the soil.
This can be a problem for the plant because it’s not able to reach deep to take nutrients from the soil. Once the vital nutrients close to the surface are gone, your plant will start to suffer.
If you suspect that a lack of nutrients is to blame for your lack of blossoms, consider doing some soil tests. A soil test can give you an accurate reading about the overall vitality of the soil.
Provide a single application once in the spring. That fertilization should serve you well for a couple of years. There’s no need for repeat applications. Before you consider providing more fertilizer, do a soil test to ensure that you’re not going overboard with the nutrients.
3. Transplant Shock
Transplant shock is a very real issue that affects all kinds of plants. Plants can have trouble adapting to the new location. This causes stunted growth, increased susceptibility to disease, and a range of other issues.
The peony is a bit more sensitive than others. These plants do not like the transplantation process. If you transplant a mature plant, your risks of shock are even greater.
Peony plants have a unique root structure. It looks similar to a bunch of carrots. As the plant matures over several years, this root bunch will get larger and larger. The bigger it is, the riskier transplantation becomes.
If you transplanted your peony within the last year or two, the shock could be a reason for peony not flowering.
There’s not much you can do to an already transplanted peony. It can take several years for the plant to bounce back. Just keep providing it with the care it needs until it blossoms.
The best way to avoid transplant shock in the future is to divide the plant. Division involves snipping off parts of the root. Think of it as propagating a stem. But instead of a stem, you’re dealing with the root system.
Divided plants accept transplantation much better. In fact, a division can rejuvenate the plant. Not only do you improve the chances of the divided plant growing strong, but the original plant may experience more blooms, too.
It’s best to divide peonies once they are dormant, which is around August to October. Cut back the stems of the plant and dig out one of the chunkier roots on the perimeter of the root clump. You can move this clump to another part of your garden and wait for growth next year.
4. Too Much Depth
Peonies have relatively shallow roots. Most gardeners will instinctively plant roots deep into the soil to ensure that the plant is strong. For most flowers, that’s not a problem. But for the peony, it can actually set the plant back several years.
The root mass we discussed earlier, which is sometimes called the crown, has tiny tubers on them. Some gardeners call the tubers “eyes” or “buds.” They are the tiny white or pink growths coming out of the root mass. This is what the plant will grow out of.
The tubers need to be close to the surface of the soil. If not, the plant will not blossom in the spring.
The best course of action here is to replant your peony at a more shallow soil level. This will not fix the problem immediately. It will set the plant back a year or two, so don’t expect to see blossoms now or in the following growing season.
Because it takes so long for the plant to get established, you have to make sure that you’re planting it correctly.
Dig a shallow hole that’s wide than the root mass. Take note of where the tubers are. Arrange the roots so that all of the tubers are facing upwards. Place the root mass into the ground and make sure that the tubers are only 1.5 to 2 inches below the surface of the soil.
This may take some trial and error. If the depth isn’t right, put some soil back into the hole until the depth is perfect.
5. Lack of Cold
Did you know that peonies need a certain amount of cold exposure to blossom? In gardening, we often view cold weather as the enemy. But for many plants, it’s essential.
This cold exposure requirement is its “chilling hours.” If your peony isn’t blooming, it probably didn’t get enough chilling hours. This is pretty common with those in warmer climates.
The plant might have only gotten a portion of its required chilling hours but not enough to fully bloom. This is evident if you have buds but no blossoms.
A peony needs between 500 and 1,000 chilling hours. The ideal temperature for this chill time is around 40 degrees Fahrenheit. Generally, any time in temperatures below 45 degrees but above freezing.
There’s not much you can do this growing season if chill hours are the problem. Next year, remove any barriers that could block the wind. Don’t cover the plant and let it get the exposure it needs.
6. The Plant is Too Young
Did you recently plant your peony? If so, the problem can be staring you right in the face.
Peonies take a long time to grow. They are perennials after all. Perennials rarely bloom in the first year. The plant needs to mature first.
Chances are, you’re not going to see any flowers in the first year. This is for peonies that you get at the nursery. If you’re starting from seed, you could be looking at up to five years before the first flowers appear.
Even then, the first flowering year is going to be sparse. It’ll take a few more years until the blooms really start taking off.
There’s only one solution here: Wait.
Be patient and give your peony some time. Trust me: the wait is worth it.
7. Too Much Pruning
Over-pruning is a big problem with peonies. This hardy plant needs its leaves to gather sunlight and photosynthesize. The photosynthesis process that occurs while a plant is blooming actually creates energy for next year’s blooms.
Think about how you pruned the flower last year. Did you cut back stems and spent buds once the flower fell off? That could be your problem. You removed the plant’s ability to collect energy, which is having an impact on its ability to bloom now.
Pruning can be beneficial. But, you have to be careful not to overdo it. The foliage on the peony will naturally die off in the winter. This occurs after the plant goes dormant.
If your plant is already pretty healthy, there’s no reason to prune. Doing so could just damage the plant and cut off its energy supply.
Never prune more than a third of the plant. Furthermore, you should avoid pruning in the fall. Let nature do its thing. When you prune stems in the fall, those stems will not produce buds the next year.
You can prune unruly branches in the spring before the plant goes dormant. But only do this if the branches are affecting the plant’s ability to develop further.
Earlier, I said that a lack of nutrients could be the problem that’s preventing your peonies from blooming. However, the opposite could be true, too.
Too much fertilizer can stunt the development of flowers. That’s why you have to be extra careful about not overdoing it.
The main issue with overfertilization is excess nitrogen. Nitrogen is one of the “Big Three” nutrients in commercial fertilizers. It’s responsible for promoting more leafy foliage.
Therein lies the problem. When the plant has an overabundance of nitrogen, it’ll use that nutrient to produce more leaves and stronger stems. But, none of that nitrogen will help produce buds. As a result, you’ll have a lush peony bush with no flowers.
Pay close attention to the fertilizer you’re using. Go for one that’s low in nitrogen.
Even then, you might want to consider doing a half-strength application. Use only have the recommended amount of water-soluble granules to dilute the fertilizer to a safer level.
9. Late Frost
Exposure to cool weather is important to peonies. But too much of it could lead to some problems.
For the most part, these plants are quite hardy and can withstand late frosts without too many problems. However, they have their limits.
Exceptionally deep frosts with temperatures below 28 degrees Fahrenheit could kill the plant. This is especially true if the frost occurs after some flower buds appear. The frost will kill the buds, resulting in a year without blossoms.
Always stay on top of weather conditions. If you receive a hard freeze advisory in the late winter or early spring, you need to take some steps to protect your peony.
Cover the plant with an old blanket. Use stakes to hold the blanket over the plant and avoid physical damage. Make sure to secure the bottom of the blanket as well.
The blanket will keep the plant insulated enough to avoid major frost damage.
10. Poor Soil
Sometimes, the issue could be right underfoot. Peonies aren’t suitable for all types of soil. While your garden soil might be conducive for growing other plants, there’s a good chance that you need to do some amending for peonies.
The ideal growing medium is soil that’s loose and well-draining. Peonies prefer moist soil that’s also on the acidic side. A pH balance between 6.0 and 7.0 is ideal.
As always, rich nutrients are a must, too. The soil needs to be fertile enough to support the plant for years to come.
Resolving soil issues after your plant has started growing is difficult. You may have to transplant the peony to a better spot to see results. Even then, it will take some time for the plant to bounce back.
Choose an appropriate planting site and take some time to prepare the soil. Loosen the dirt to aerate it. If your soil is high in clay, add compost or soil mix to keep it loose. The compost will also help to improve the nutrient content.
To raise pH levels, mix in some peat moss. Work the soil well and test it frequently to ensure that it’s ready for your peony.
There are a handful of different pests that will invade your peonies. Generally, peonies aren’t as susceptible to pest infestations as other flowers or crop plants. But if bugs get the chance to move in, they will do a lot of damage to this delicate perennial.
Pests will feed on sap within the stem and leaves. Some will even attack the root crown or buds.
Needless to say, any form of pest damage is not good for the plant. Your peony will have to focus on healing those wounds, resulting in less energy for blooming.
Severe damage could also have a bigger impact on the plant. Depending on the size of the pest problem, you could end up with shriveled leaves and dying stems. Plus, physical damage to buds will kill them off before they get a chance to blossom.
The most common pests to attack the peony plant are mealybugs, thrips, Hoplia beetles, bulb mites, and armored scales.
The good news is that pests aren’t too difficult to get rid of with the right pesticide. You can use an organic pesticide, such as neem oil, or a chemical-based product.
Whatever you choose, it’s best to apply the product relatively early in the growing season. Most pests will start to appear once the flower buds appear. Time your application just right and you should be able to get rid of pests quickly.
Apply the pesticide early in the mornings so that the foliage has time to dry before peak temperatures.
Peonies are at risk of suffering from various diseases. Most of them are fungus-based. One of the most devastating diseases is botrytis blight.
Botrytis blight will wreak havoc on several parts of the plant. It can cause cankers on the stems, black and brown patches on leaves, and more. In severe cases of botrytis blight, the stem can suffer so much that it just turns black and falls over.
However, one of the most devastating effects it has on the plant is killing the buds. The disease turns buds brown and makes them fall out.
The key to addressing diseases like botrytis blight is to create an environment where it can’t survive.
Fungus thrives in moist environments with poor aeration. Make sure that your plant can breathe. Soil should have good drainage and prevent standing water.
If you see affected buds, snip them off immediately to avoid the spread of the disease. Keep patchy leaves. The plant still needs those to photosynthesize. However, you can cut them off at the end of the season.
Apply a layer of fresh mulch around the base of the plant. This might seem counterintuitive. But, it can prevent spores from returning.
Fungal spores will overwinter in the soil and migrate back up to disease the plant once the weather warms up. With a layer of fresh mulch, the spores will stay put.
13. Environmental Stress
Did you experience any severe weather this year? If so, your peonies might have experienced some environmental stress it’s trying to recover from.
Environmental stress can be many different things. Everything from severe cold to excess heat will put undue stress on the plant. Anything outside of its ideal growing conditions is not good.
The problem with environmental stress is that it stunts the development of buds. It causes bud blast.
Bud blast occurs when otherwise healthy buds turn brown and black. The bud withers and falls off rather than blooming.
Environmental stress is one of the leading causes of bud blast. Another common cause is botrytis blight.
Unfortunately, there’s not much that you can do to fix growth issues from environmental stress.
Make sure that your garden has optimal conditions for peonies. These flowers don’t grow well in tropical or subtropical climates. They require mild summers and cool winters. If you live in an area with extreme weather, peonies aren’t an ideal plant to cultivate.
14. Overwatering or Underwatering
Peonies need just the right amount of water to truly thrive. Too much or too little will result in growth problems.
Too much water is a serious problem that will impact the overall health of the plant. Peonies hate standing water. The soil must have adequate drainage to prevent issues like root rot and fungus.
They also hate long dry periods. Peonies are drought tolerant to a small degree. But prolonged dry spells will only harm the plant’s ability to produce blossoms.
Your peony plant will need roughly 1 inch of water each week. It may need a little more or a little less depending on the weather and temperature.
If there’s any plant to use a moisture gauge on, it’s the peony. Use it to determine if the soil is too dry or too moist. Don’t rely on a set schedule alone. These plants are sensitive and will not tolerate major watering issues.
When you water your plant, make sure to concentrate on the base. Avoid getting the foliage wet to prevent mold and fungal issues.