How Much and How Often Should You Water Hydrangeas?
Are you struggling to figure out how much or how oftern to water your hydrangeas to heep them looking great? Overwatering and underwatering hydrangeas is a common problem that's easily solved. In this article, gardening expert and hydrangea enthusiast Jill Drago examines how much water your hydrangeas need, and how frequently you should water them.
The hydrangea inherited its name from two Greek words: hydros (water), and angos (jar or vessel). It is said that this is because the flowers reminded botanists of an actual pitcher of water, but the irony is not lost on me.
Hydrangeas are classified as plants that need a lot of water. This is both true and false. Yes, they need a lot of water while they are becoming established. They are not considered drought tolerant plants, so they will always need some supplemental watering where other shrubs and perennials may not.
Getting a handle on how much water your hydrangea needs, and how to water correctly will set you off to a successful hydrangea garden. Let’s dive in and take a deeper look at how much water they need, and how often you should be watering them!
Contents
The Short Answer
Once established, hydrangeas should be watered about one inch per week, spread across 3 watering sessions. The water should be evenly distributed at the roots, and never over the top of the plant. Watering top down will encourage fungal disease, and potentially harm the plant. You may need to water slightly more, and more frequently during periods of extreme heat.
Why Watering Correctly Matters
Watering really is a no brainer task. While it may be simple, it is so very important if you want to have long living, healthy plants in your gardens. Overwatering can cause many common problems, and introduce fungal diseases. Underwatering can cause stress and browning of the foliage and flowers.
Overwatering Symptoms
- Leaves may be brown and wilted.
- Leaves may turn yellow and fall off.
- One side of the plant may show signs of root rot.
- This will look like the plant is dying.
- Stunted or no flower growth.
Underwatering Symptoms
- Wilted leaves that will pop back when the day cools.
- Flowers will turn brown.
The Long Answer: Watering Correctly
Now that you understand the drawbacks of both underwatering and overwatering, let’s take a look at the correct way to water your hydrangeas, how often you should be watering them, and how much water you should be using on a consistent basis.
Water Slow and Deep
Watering with a nice shower setting on your hose is a good way to go with your hydrangeas. This will provide gentle watering that will be able to be absorbed by the soil. If you water with too much pressure, the water will likely just run off.
If you are able to use a soaker hose or drip irrigation, that would be ideal. This slow and controlled method of watering will get the water exactly where it needs to go, and limit the water waste that comes along with run off.
Avoid Overhead Watering
Hydrangeas are susceptible to fungal diseases. When you use an overhead sprinkler, or if you aim your hose at the top and simply spray your leaves, you will be doing more harm than good.
Many fungal diseases spread through the splashing of water. When you allow water to collect on the flowers and leaves you are increasing the risk of the spread of these diseases. Keep in mind, it is the roots that need the water not the leaves.
Using a soaker hose, drip irrigation, or just paying close attention while hand watering will keep the water you are providing your plant at the base. This will save water, keep the top of the plant nice and dry, and provide your plant with plenty of available water.
Add Mulch
Whether or not they struggle with drying out, it is recommended to add an inch or two of mulch around the base of your plant. This will hold moisture in the soil as well as keeping weeds at a minimum. Those annoying little weeds suck up a lot of water in the hot summer months, and can actually rob your hydrangeas of a drink.
Gardens that are mulched have a much higher success rate of retaining water, and preventing runoff. This is important for water as well as fertilizer, so it’s a win-win.
Watering Frequency
The rule of thumb for watering hydrangeas is three times a week. Now since we don’t all live in a bubble there are other factors, such as weather, that you will need to take into consideration when deciding if you need to water or not.
Species Matters
Bigleaf, mountain and smooth hydrangeas need more water than other hydrangea species. If you are looking for a species that is a bit more drought tolerant you will want to plant oakleaf or panicle hydrangeas.
This is important to keep in mind, as is where you end up planting them. Some varieties that prefer more shade can still live with more sun, but may need extra moisture to compensate for that additional exposure.
Climate and Rainfall
Hydrangeas grow in USDA zones 3-8. Some species grow better in cooler climates while others do better in the warmer climates.
No matter what, if you are planting in a warmer climate (even if it is in the shade) you will need to water more frequently than if you are in a cooler climate. These warmer climates could be anywhere from zones 7 and up! The rate of evaporation will be higher, and can lead to trouble.
Soil Conditions Matter
Hydrangeas do best in well-draining soil. They love the soil around them to be moist, but not wet. Wet feet can lead to root rot, but it can also lead to smaller flowers and in some cases no flowers at all.
If you have sandy or heavy clay soil it is a good idea to amend your soil with some compost, peat moss, or other organic material that you feel comfortable using. This will help retain the right amount of moisture.
Location
The amount of water your hydrangea may need will differ on where it is situated in your garden. For instance: those planted in containers will need to be watered more frequently.
Containers can only hold so much, so the slow, deep watering that is best for gardens won’t work here. Depending on the size of your container and the size of the plant, you may need to water every day. The best way to know this is if the leaves are drooping, and if the soil is dry to the touch.
Life Stage Matters
When you have fresh transplants, you will want to be watering it more frequently to help it get established in your garden. Fully establishing a hydrangea in your garden can take anywhere from 1-3 years.
If you have a happy healthy plant that has been living in your gardens for a while now, you will not need to water as frequently. This is where the three times a week comes into play.
How Much Should I Water?
Hydrangeas need about one inch of water per week. How do you figure that out?
Well, if you will be getting a lot of rain you can always use a rain gauge in your garden to see how much rain you have gotten. Position this rain gauge near your plant to get an accurate measurement.
If you plan to be watering by hand it is really hard to measure how much water they are getting. In this case, it will be best to get familiar with your soil. Sticking your finger into the soil will give you a good idea of how dry it may be. It should be moist, not sopping wet.
Final Thoughts
If you are in your garden and watering regularly, you are likely doing enough for your hydrangeas. Keep your eyes open for the tell tale signs of over watering, and drought stressed plants and you will have a better understanding of what your plant needs from you.
Hydrangeas are resilient plants, and can overcome drought and drowning with a little bit of love from you. Do not get discouraged, with a little bit of practice this will become second nature and you will have gained a bit of new gardening knowledge!
