Peonies do not only produce beautiful blooms—but they are also pretty easy to maintain once established and can thrive for decades when left undisturbed. It is difficult to under-water them as they can be drought-tolerant, but they may suffer from neglect, so you should water them accordingly.
You should water your peony plants once a week at moderate temperatures. The frequency of watering depends on several factors, such as the age of the plant, the size of the plant, the number of companion plants around them, and the season.
Further, we will discuss how often to water your plants based on the factors mentioned. I will also explain the effects of over-watering or under-watering on your peony plants. Read on!
Factors Affecting How Often You Should Water Your Peony Plants
There is no definite answer to how often you should water your peony plants because these plants have different watering needs at different life stages, seasons, and environments. However, based on these factors, you can decide how much and how often to water your plants.
Let’s take a look at how they affect your peony plant’s watering needs:
Age of the Peony Plant
Peonies naturally have different water requirements at different stages of their growth. The frequency and amount of water you provide your plant are crucial to how successfully they can mature.
Peony seedlings need well-draining soil in all life stages, as it can help prevent waterlogging. When placed outdoors, seedlings can receive enough moisture from the rain.
However, heavy rain can be dangerous because it can keep the soil too wet for the peonies’ developing roots. You can move the potted seedlings into a roofed area and keep the soil moist by watering them thoroughly once every two weeks.
After Growing True Leaves
It usually takes around two years before peonies develop true leaves. And when they do, they will need more water. You can start watering your peonies once a week. Other environmental factors such as the temperature and amount of rainfall may require you to adjust the watering frequency. Either way, you want to keep your soil damp but not waterlogged.
Fully Established Peony Plants
At 3-4 years old, peonies are likely already established and may require less frequent watering, except during budding and blooming periods. Water once a week but at higher volumes, as adult plants also need large amounts of water to stay healthy and happy.
Add water gradually until the soil stops absorbing the water. You will know this when you see a small pool building up at the base of the plant.
Your peonies will need more water when they are in the budding stage. Note that peonies typically bud early in the spring and bloom from the middle of spring to early summer.
To help the buds bloom, you will need to provide water more frequently (i.e., twice a week). However, you may have to cut off the buds when your peonies are less than two years old so the plant can focus on root and foliage development.
Size of the Peony Plant
Peonies can tolerate different types of soils but will grow best in loamy soil with good drainage.
You should also take care to plant your peonies at the right depth.
Regardless of the age and size of the peony plant, as long as they are planted correctly and the soil has good drainage, you wouldn’t have to worry about over-watering them.
Heavy and continuous rains are the main reason peonies get overwatered. That is why it is best to grow them in pots as seedlings while they are still developing their roots.
You can then transplant seedlings with healthy roots into the ground in your garden. Just be careful in choosing a spot, as the peonies will ideally stay there for several years or even decades.
Bigger plants naturally need more water than smaller plants. However, you don’t need to water them more frequently because their fully developed roots can absorb water quickly, while their stems and leaves can store them efficiently until the next watering session.
That is why it is necessary to water mature peonies (over three years of age) thoroughly every week and allow the soil to dry a bit before watering them again.
Peonies have various watering requirements like any other plants depending on the season. Beyond the age and size of the plant, you should consider the seasons and the environmental temperatures when watering your plants.
Some peonies may form buds in their first year. You need to nip them off to prevent them from competing for nutrients otherwise intended for root and foliage growth.
Buds from mature plants, however, will need more water to open and bloom. They typically come out in the middle of spring. Therefore, water your plants more frequently than you usually do.
Water the soil when you notice the upper surface drying up. Remember never to water your peonies from the top, as the excess moisture on the flowers and the leaves can invite fungal infections like powdery mildew and leaf spots.
However, if you intend to remove the buds to place in vases on your counter or gift your family and friends, you may not need to water the peonies more frequently. Ensure that you add enough water when the upper 1 inch (2.54 cm) of soil is dry.
Some peonies continue to bloom until the middle of summer. When you notice buds forming early in the season, you will need to water the plants more. High temperatures can remove moisture more quickly through evaporation.
Water the plants twice a week. Peonies can benefit from deep watering to replenish the moisture lost through transpiration during hot weather.
If your area is prone to heavy summer rains, you may want to cut back on watering. It also helps to check weather forecasts to know how much precipitation to expect. The last thing you would like is to over-water your peonies.
In the fall, you can return to your regular watering schedule. Peonies will be fine with weekly watering and can endure dryness on the soil layer’s upper 1-2 inches (2.5-5 cm) before the next watering session.
Adjust your watering schedule depending on the amount or frequency of autumn rain in your area to prevent the soil from being waterlogged. Also, you can reduce the watering frequency as temperatures drop below 60°F (15.6°C).
You can water your plant once every two weeks. Be sure to always check the soil for moisture. If you cannot trust your judgment from physical observation, you can use a device to check the moisture level in the soil. It can help you decide when it’s time to water your plants and address any issues of over-watering or under-watering.
You can cut back on watering during winter, but you must ensure that the soil stays damp. When the ground feels dry, feed your peonies tepid distilled water to protect them from cold shock. During this time, your peonies do not need deep watering.
Winter is also the best time to remove weeds around your peony plants. Since you won’t be adding more water to your plants during winter, you wouldn’t want weeds stealing what little moisture your peonies have.
Apply mulch to the soil around the base of the plant in winter. The mulch can provide insulation to protect the roots from freezing temperatures and help retain moisture during dry winter days.
Type and Number of Companion Plants
Whether herbaceous or tree-type, peonies do not like being grown alongside other trees or plants as it can limit the amount of water and nutrients they can get from the ground due to competition.
Although they look exceptionally well with other flowering plants or those with colorful foliage, it would be best to select plants that can be safely grown in pots to avoid competition.
If you have to grow them with other companion plants on the same ground, you may need to water them more frequently. Growing plants with similar water requirements are best to protect them from water-related problems.
What Happens When You Over-Water Peonies?
Your peonies are more likely to suffer irreversible damage from over-watering than under-watering. That is why you should pay attention to your peonies’ watering needs and avoid overdoing it.
When you over-water peonies, they will become vulnerable to root rot and show physical signs of damage, such as leaf blights, wilting, and drooping. In worse cases, they can die and infect other plants in your garden.
Most symptoms of overwatering are associated with secondary fungal infections. The constantly wet conditions make the soil conducive for microbial growth and weaken the plant’s structures, making them vulnerable to diseases.
Some signs that your peonies are over-watered:
- Water-soaked lesions on the leaves or stems.
- Black roots.
- White, powdery mildew on the leaf surface.
- Brown leaf spots.
- White webby structures on the stem.
Peonies become especially susceptible to various fungal diseases during rainy seasons. The constantly water-logged conditions can cause peonies to die and may require you to pull them out and burn them to avoid infecting other nearby plants.
What Happens When You Under-Water Peonies?
Once fully established, adult peonies are a bit drought-tolerant. They can store and live off some moisture in their stems and leaves. However, they can suffer from chronic under-watering.
When you under-water peonies, you will not see any negative signs right away since the plants can endure a bit of dry soil. However, extended periods of drought will cause the plant to wilt and fail to form flowers.
Some signs your peony plants are under-watered include:
- Crisp, dry leaves.
- Leaves browning on the edges.
- Failure to open the buds.
- Dry, cracked soil.
Peonies are pretty sturdy and drought-tolerant once fully established. They require little maintenance as long as the roots stay undisturbed.
How often you should water your peony plants largely depends on several factors, including:
- The peony’s size.
- The plant’s age.
- The season.
- The plants around them.
The most important thing to consider when watering peonies is to avoid over-watering them, as the problems it may cause are typically harder to deal with than when they are under-watered.